TO 35-1-3

TECHNICAL MANUAL

CORROSION PREVENTION AND CONTROL, CLEANING,

PAINTING, AND MARKING OF USAF SUPPORT
EQUIPMENT (SE)
This manual supersedes TO 35-1-3 dated 26 April 2014, Change 20 dated 26 January 2022.

DISTRIBUTION STATEMENT A - Approved for public release; distribution is unlimited. PA Case Number 05-07173. Other requests for this
document shall be referred to 406 SCMS/GUEE, Robins AFB, GA 31098. Questions concerning technical content shall be referred to
AFLCMC/EZPT-CPO.

Published Under Authority of the Secretary of the Air Force

13 DECEMBER 2024
TO 35-1-3

INSERT LATEST CHANGED PAGES. DESTROY SUPERSEDED PAGES.

LIST OF EFFECTIVE PAGES NOTE The portion of the text affected by the changes is indicated by a vertical line in the outer
margins of the page. Changes to illustrations are indicated by shaded or screened
areas, or by miniature pointing hands.

Dates of issue for original and changed pages are:

Original . . . . . . . . 0 . . .13 December 2024
TOTAL NUMBER OF PAGES IN THIS PUBLICATION IS 104, CONSISTING OF THE FOLLOWING:

Page *Change Page *Change Page *Change

No. No. No. No. No. No.

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2-1 - 2-22 . . . . . . . . . . . . . . .0
3-1 - 3-29 . . . . . . . . . . . . . . .0
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A-1 - A-6 . . . . . . . . . . . . . . .0

* Zero in this column indicates an original page.

A USAF
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TABLE OF CONTENTS
Chapter Page

LIST OF ILLUSTRATIONS ............................................................ vi

LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

SAFETY SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

1 CORROSION THEORY, IDENTIFICATION, CAUSES AND EFFECTS . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.1 PURPOSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.2 DEFINITION OF CORROSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.3 CHEMICAL DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.3.1 Atom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.3.2 Electron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.3.3 Ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.3.4 Electrolyte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.4 THEORY OF CORROSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.4.1 Anode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.4.2 Cathode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.4.3 Electrolyte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.4.4 Electrical Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.5 DEVELOPMENT OF CORROSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.5.1 Corrosion Origination Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.5.2 Corrosion Under Painted Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.6 FACTORS INFLUENCING CORROSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1.6.1 Type of Metal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1.6.2 Dissimilar Metal Coupling (Galvanic Corrosion) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1.6.3 Anode and Cathode Surface Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1.6.4 Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1.6.4.1 Desert . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1.6.4.2 Temperate Zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1.6.4.3 Tropics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1.6.4.3.1 Factors of Influence in Tropical Environments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1.6.5 Heat Treatment and Grain Direction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1.6.6 Electrolytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1.6.7 Microbial Induced/Influenced Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
1.6.8 Mechanical Stress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
1.6.9 Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
1.6.10 Manufacturing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
1.6.11 Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
1.6.12 Degradation of Non-metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
1.6.13 Preventive Maintenance (PM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
1.7 TYPES OF CORROSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
1.7.1 Uniform Etch Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
1.7.2 Galvanic Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
1.7.3 Pitting Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
1.7.4 Intergranular Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
1.7.5 Exfoliation Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
1.7.6 Concentration/Crevice Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
1.7.7 Stress Corrosion Cracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
1.7.8 Hydrogen Embrittlement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
1.7.9 Corrosion Fatigue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13

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1.7.10 Filiform Corrosion . . . . . . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13

1.7.11 Fretting Corrosion . . . . . . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
1.8 METALS AFFECTED BY CORROSION .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
1.8.1 Magnesium . . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
1.8.2 Steel . . . . . . . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
1.8.3 Aluminum . . . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
1.8.4 Copper and Copper Alloys . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
1.8.5 Stainless Steel . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
1.8.6 Nickel and Chromium . . . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15

2 CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.1.2 Support Equipment (SE) Wash Cycles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.1.2.1 War Reserve Materiel (WRM) Support Equipment Wash Exemption Waivers . . . . . . . . . . . . . 2-1
2.1.3 Definition of Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
2.1.4 Types of Cleaners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
2.1.5 Methods of Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
2.1.6 Cleaning Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
2.1.7 General Cleaning Material and Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
2.1.7.1 Cleaning Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
2.1.7.2 Cleaning Compounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
2.1.7.3 High Pressure Wash/Hot Water Wash Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
2.1.7.4 Water Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
2.1.7.5 Deployed/Remote Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
2.1.7.5.1 Water Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
2.1.7.5.2 Engines and Engine Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
2.1.7.6 Water Quality/Recycled Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
2.1.8 Cleaning of Non-metal Parts Prior to Painting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
2.1.8.1 Composites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
2.1.8.2 Plastics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
2.1.9 Cleaning of Electrical Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
2.1.10 Preparation of SE for Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
2.1.11 Cleaning of Engine Components and Enclosures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15
2.2 MECHANICAL CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16
2.2.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16
2.2.2 Coating Removal on Composite Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16
2.2.3 Coating Removal on Metallic Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17
2.2.4 Grinding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17
2.2.5 Wire Brushing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17
2.2.6 High-Pressure Water (HPW) Paint Removal Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18
2.2.6.1 Authorized HPW Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18
2.2.6.2 Training Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18
2.2.6.2.1 Manufacturer Provided Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18
2.2.6.2.2 Locally Developed Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18
2.2.6.3 Personnel and Equipment Preparation Prior to HPW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18
2.2.6.4 HPW Paint Removal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19
2.2.6.5 Post HPW Paint Removal Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19
2.2.7 Handheld Laser (HHL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20

3 PAINTING, SEALING, CORROSION PREVENTIVE COMPOUND APPLICATION . . . . . . . . . . . . . . . . . . 3-1

3.1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

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3.1.1 Coating Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.2 DEFINITION OF EXPOSURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.3 REQUIREMENTS FOR PAINTING-FIELD LEVEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.3.1 Coating Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.3.1.1 Corrosion Control Scoring Program and Complete Repainting Criteria . . . . . . . . . . . . . . . . . 3-1
3.3.1.1.1 Corrosion Scoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.3.1.2 Scoring Categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
3.3.1.2.1 Complete Repaint Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
3.3.2 Abrasive Blasting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
3.3.2.2 Medium Pressure Water Blasting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
3.3.2.3 Scuff Sand and Overcoat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
3.3.2.3.3 Preparation and Priming of Plastic Components/Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
3.3.3 Temporary Coating Repairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
3.3.3.1 Rust Converters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
3.3.4 Touch-up Primer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
3.4 REQUIREMENTS FOR PAINTING-DEPOT LEVEL AND CONTRACTOR SUPPORT . . . . . 3-5
3.4.1 Coating Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
3.4.1.1 Corrosion Rework Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
3.4.2 Contractor Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
3.5 AUTHORIZED COLORS, SEMPENS, AND MATERIALS . . . . . . . . . . . . . . . . . . . . . . . . 3-6
3.5.1 SE Standardized Colors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
3.5.2 SE Standard Topcoat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
3.5.3 Authorized Colors for Liquid Oxygen, Nitrogen, Storage Carts and Tanks . . . . . . . . . . . . . . . 3-6
3.5.4 Passenger or Loading Ramps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
3.5.5 Presidential Support Equipment and USAF Demo Team . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
3.6 CORROSION TREATMENT FOR STEEL CABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
3.7 PIANO TYPE HINGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
3.8 MATING SURFACES PROTECTION REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . 3-14
3.8.1 Mating Surfaces-Bare Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14
3.8.1.1 Mating Surfaces-All Other Metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14
3.8.2 Sealers and Sealant Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14
3.9 ACOUSTICAL MATERIAL PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
3.9.1 Coustifoam Polyurethane Insulation and Acoustic Foam . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
3.9.2 Nonmetallic Fasteners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
3.10 DRAINAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
3.10.1 Fluid Collection Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
3.10.2 Modifying Fluid Collection Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
3.11 MAINTENANCE STAND RAILS AND RAIL HOLDERS . . . . . . . . . . . . . . . . . . . . . . . . . 3-17
3.11.1 Drain Holes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17
3.11.2 Drain Hole Corrosion Prevention and Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17
3.12 HOLLOW STRUCTURAL MEMBERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18
3.12.1 Drainage for Closed Hollow Members, When Open Drain Holes are Possible . . . . . . . . . . . . . 3-18
3.12.2 Drainage for Closed Hollow Members, When Open Drain Holes are Not Possible . . . . . . . . . . 3-18
3.13 CORROSION PREVENTIVE COMPOUNDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18
3.13.1 MIL-PRF-81309 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19
3.13.2 MIL-DTL-85054 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19
3.13.3 MIL-PRF-16173 CPC Solvent Cutback, Cold Application . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19
3.13.4 MIL-PRF-63460 Lubricant, Cleaner, and Preservative for Weapons and Weapon Systems . . . . . 3-20
3.13.5 MIL-L-87177 Lubricants, Water Displacing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20
3.13.6 CPC Methods of Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20
3.14 CPC APPLICATION ON FERROUS ALLOYS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20
3.15 CPC APPLICATION ON OTHER ALLOYS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20
3.16 COATING APPLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
3.16.1 Material Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
3.16.2 SE Surface Preparation Categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22

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3.16.3 MIL-PRF-85285 Polyurethane, Type IV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22

3.16.4 Thermal Spray Coating Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23
3.17 FIELD LEVEL MAINTENANCE PAINTING REQUIREMENTS . . . . . . . . . . . . . . . . . . . . 3-24
3.17.1 Touch-Up Painting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25
3.18 MAINTENANCE PAINTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25
3.18.1 Maintenance Painting Restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25
3.18.2 Prepackaged Coating Touch-Up Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25
3.18.3 Radiators Coatings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25
3.19 LIQUID OXYGEN AND LIQUID NITROGEN SERVICING CARTS AND STORAGE
TANKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25
3.19.1 Authorized Materials for Liquid Oxygen and Nitrogen Tanks . . . . . . . . . . . . . . . . . . . . . . . . 3-26
3.20 WALKWAYS AND STEPPING SURFACE COATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
3.21 COLORS FOR WASTE CONTAINERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
3.22 SE UNDERCOATING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
3.22.1 SE Undercoating Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
3.23 STORAGE COMPARTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
3.24 SPLIT WHEEL ASSEMBLIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27
3.24.1 Split Wheel Coating Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27
3.25 MUFFLERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27
3.26 MISCELLANEOUS CLEANING, SEALING, AND CPC REQUIREMENTS . . . . . . . . . . . . 3-28
3.26.1 Sealing of Addressograph or Dash-A Plates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28
3.26.2 Electrical Hardware and Terminals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28
3.26.3 Light Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28
3.26.4 Internal Electrical Components: Circuit Breakers, Relays, etc . . . . . . . . . . . . . . . . . . . . . . . . 3-28
3.26.5 Electrical Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29
3.26.6 Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29
3.26.7 Wire Harness and Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29
3.26.8 Heli-Coil Insert Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29

4 MARKING OF SUPPORT EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.1 SE MARKINGS CROSS-REFERENCE ..................................... 4-1

5 CORROSION PREVENTION AND CONTROL OF HUSH HOUSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.1 MATERIALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.1.1 Fastener Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.2 REPAIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.2.1 Galvanized Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.2.2 Carbon Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.2.3 Stainless Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
5.2.3.1 Type 321 Stainless Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
5.2.3.4 American Iron and Steel Institute (AISI) 409 Stainless Steel . . . . . . . . . . . . . . . . . . . . . . . . 5-2
5.2.3.7 Sealing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
5.3 PRETREATMENT COMPOUNDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
5.3.1 Rust Remover 81287 (Naval Jelly) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
5.4 PRIMERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
5.4.1 Organic Metal-Rich Primer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
5.4.2 Inorganic Zinc-Rich Primers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
5.5 PAINTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
5.5.1 Structural Corrosion Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
5.5.2 Camouflage Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
5.6 INORGANIC ZINC PRIMED SURFACES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
5.6.1 Primer Requirements on the Door Frame Beams, Support Beams, and Exhaust Tube . . . . . . . . 5-4

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5.7 GALVANIZED SURFACES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

5.7.1 Roof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
5.7.2 Walls and Doors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

6 CORROSION PREVENTION AND CONTROL OF NOISE SUPPRESSOR SYSTEMS (NSS) . . . . . . . . . . . . 6-1

6.1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

6.2 MATERIALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
6.3 FASTENER REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
6.4 STRUCTURAL REPAIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
6.4.1 Structural Repair Carbon Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
6.4.2 Galvanized Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
6.4.3 AISI 409 Stainless Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
6.5 SEALING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
6.6 PRIMERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
6.6.1 Organic Zinc-Rich Primers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
6.6.2 MIL-PRF-23236, Type I, Class 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
6.6.3 Heat Resistant Primer Briner 2905 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
6.6.4 Heat Resistant Silicone Coating-Briner 2986 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
6.6.5 High Temperature Resistant Silicone Coating-Briner 4765 . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
6.6.6 High Temperature Resistant Silicone Coating Thurmalox 270-18 . . . . . . . . . . . . . . . . . . . . . 6-4

7 SOUTHWEST ASIA OPERATIONS AND ENVIRONMENTS ................................. 7-1

7.1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.1.1 Environmental Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
7.1.1.1 Soils and Humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
7.2 SE SWA AOR DEPLOYMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
7.2.1 Pre-deployment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
7.2.2 Deployment Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
7.2.2.1 SE Units Requiring Additional Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
7.2.2.1.1 Radiators, Vanes, Filters and Coils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
7.2.2.1.2 Portable Hydraulic Test Stands/Mobile Air Compressors . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
7.2.2.1.3 Aircraft Jacks and Tow Bars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
7.2.2.1.4 Open Circuit Boards/Cards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
7.2.2.1.5 Wire Bundles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
7.2.2.1.6 Felt-Soundproofing Insulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
7.2.3 Maintenance Touch-Up Painting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
7.2.3.1 Temporary Coating Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
7.2.3.2 Permanent Authorized Touch-Ups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
7.2.4 Equipment Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4

APPENDIX A EQUIPMENT AND CONSUMABLE MATERIALS USED FOR CORROSION CONTROL ..... A-1

A.1 EQUIPMENT AND CONSUMABLE MATERIALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

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LIST OF ILLUSTRATIONS
Number Title Page

1-1 Diagram of a Simplified Corrosion Cell and an Example of Raised Corrosion Product . . . . . . . . . . . . . . . 1-2
1-2 Galvanic Series of Metals and Alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
1-3 Corrosion Accelerated by Condensed Moisture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
1-4 Open Cell Foam and Resulting Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
1-5 View of the Results of Microbial Induced Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
1-6 Example of Uniform Etch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
1-7 Example of Galvanic Corrosion-Steel Hinge Bolted to an Aluminum Door . . . . . . . . . . . . . . . . . . . . . . 1-10
1-8 Example of Pitting Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
1-9 Illustration of an Intergranular Corrosion Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
1-10 Example of Exfoliation Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
1-11 Examples of Concentration/Crevice Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
1-12 Example of Exfoliation Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
1-13 Example of Filiform Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
1-14 Illustration of a Fretting Corrosion Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
3-1 Typical Marking for Paint Facility/Finish Identification Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
3-1.1 Example of Standing Water Due to Inadequate Drainage Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
3-2 Hollow Member Drain Hole Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17
3-3 Hollow Member Weld-Nut Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17
3-4 Corrosion Under Data Plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27
5-1 Angle Iron Sealant Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
7-1 SWA AOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
7-2 Sand/Dust Intrusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
7-3 Residue from Salts Caused by Condensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
7-4 Locally Manufactured Permeable Covers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
7-5 Wire Bundle Sand/Dust Accumulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

LIST OF TABLES
Number Title Page

1-1 Corrosion of Metals-Type of Attack and Appearance of Corrosion Products . . . . . . . . . . . . . . . . . . . . . . 1-16

2-1 Wash Interval Based on Corrosion Severity Zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
2-2 Authorized Cleaning Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
2-3 Authorized HPW Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20
3-1 Authorized Coating Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
3-2 SE Scoring/Category Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
3-3 Pretreatment Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21
3-4 Metalization Material Sources of Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24
5-1 Hush House Coating Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
A-1 Equipment and Consumable Materials List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

vi
 TO 35-1-3

INTRODUCTION
1 PURPOSE.

The purpose of this manual is to provide information necessary to prevent or minimize the impact of corrosion on Support
Equipment (SE). This manual is designed to provide basic corrosion principal, theory, identification, prevention and control
information to enable SE technicians to differentiate between the different types of corrosion in order to identify the appropri-
ate temporary repair materials and processes. This technical order is specific to SE; however, for areas not covered in this
manual, or expanded information on a particular material or process, technicians or contractors should refer to TO 1-1-691,
Aircraft Weapon Systems Cleaning and Corrosion Control. For additional guidance, refer to TO 1-1-8, Application and
Removal of Organic Coatings, Aerospace and Non-Aerospace Equipment, and TO 1-1-689, Avionic Cleaning, and Corrosion
Prevention/Control.

2 SCOPE.

This manual consist of the following chapters:

Chapter 1 Corrosion Theory, Identification, Causes and Effects

Chapter 2 Cleaning
Chapter 3 Painting, Sealing, Corrosion Preventive Compound Application
Chapter 4 Marking of Support Equipment
Chapter 5 Corrosion Prevention and Control of Hush Houses
Chapter 6 Corrosion Prevention and Control of Noise Suppressor Systems (NSS)
Chapter 7 Southwest Asia Operations and Environments

3 ABBREVIATIONS.

All abbreviations used in this manual are shown in the list of abbreviations below. Standard abbreviations are in accordance
with ASME Y14.38, Abbreviations and Acronyms for Use in Product Definition and Related Documents.

°C degrees Celsius
°F degrees Fahrenheit
AF Air Force
AFCPCO Air Force Corrosion Prevention and Control Office
AFI Air Force Instructions
AFOSH Air Force Office of Safety and Health
AFRL/RXSSR Air Force Corrosion Prevention and Control Office
AFTO Air Force Technical Order
AGE Aerospace Ground Equipment
AISI American Iron and Steel Institute
AOR Area of Responsibility
BBE Base Bioenvironmental Engineer
CAGE Commercial and Government Entity
CBRNE Chemical, Biological, Radiological, Nuclear, and Explosive
CPC Corrosion Preventive Compound
CRES Corrosion Resistant Steel
DO Dissolved Oxygen
DoD Department of Defense
DFT Dry Film Thickness
ESDS Electrostatic Discharge Sensitive
HHL Handheld Laser

vii
TO 35-1-3

Hp Horsepower
HPW High-Pressure Water
ID Inside Diameter
mg/L milligrams per Liter
MAJCOM Major Command
MWAS Metallization Process Metal Wire Arc Spray
NSN National Stock Number
NSS Noise Suppressor Systems
OSHA Occupational Safety and Health Administration
pH Potential of Hydrogen
PM Preventive Maintenance
PN Part Number
PPE Personal Protective Equipment
PSI Pound Per Square Inch
PSIG Pound Per Square Inch Gauge
QPL/QPD Qualified Products List/Database
OSHA Occupational Safety and Health Administration
RH Relative Humidity
RTV Room Temperature Vulcanizing
SC Sealing Compound
SCC Stress Corrosion Cracking
SDS Safety Data Sheet
SE Support Equipment
SWA Southwest Asia
TO Technical Order
USAF United States Air Force
WRM War Reserve Material

4 RELATED PUBLICATIONS.

The following publications contain information in support of this technical manual.

List of Related Publications

Number Title
AFMAN 10-2503 Operations in a Chemical, Biological, Radiological, Nuclear, and High-Yield Explosive
(CBRNE) Environment
ASME Y14.38 Abbreviations and Acronyms for Use in Product Definition and Related Documents.
DODI 5330.03_AFI 33-395 Document Automation and Production Service (DAPS)
MIL-HDBK-263 Electrostatic Discharge Control Handbook for Protection of Electrical and Electronic Parts,
Assemblies and Equipment
TO 00-5-1 Air Force Technical Order System
TO 00-25-195 Source, Maintenance, and Recoverability Coding of Air Force Weapons, Systems, and Equip-
ment
TO 00-25-234 General Shop Practice Requirements for the Repair, Maintenance, and Test of Electrical
Equipment
TO 00-110A-1 Guidelines for Identification and Handling of Aircraft and Materiel Contaminated with
Radioactive Debris (Fallout)
TO 1-1-691 Aircraft Weapons Systems-Cleaning and Corrosion Control
TO 1-1-8 Application and Removal of Organic Coatings, Aerospace and Non-Aerospace Equipment
TO 35-1-18 Marking of USAF General Support Equipment (SE)
TO 42B-1-23 Management of Recoverable and Waste Liquid Petroleum Products

viii
 TO 35-1-3

5 RECORD OF APPLICABLE TIME COMPLIANCE TECHNICAL ORDERS (TCTOS).

List of Time Compliance Technical Orders

TCTO TCTO TCTO

Number Title Date
None

6 HARDNESS CRITICAL ITEMS (HCI).

The HCI symbol ( ) establishes special requirements limiting changes and substitutions and that the specific
parts listed must be used to ensure hardness is not degraded. Failure to comply could result in damage to, or
destruction of, equipment or loss of mission effectiveness. Failure to comply could result in damage to, or destruc-
tion of, equipment or loss of mission effectiveness.

If included, items with nuclear survivability requirements are marked with the HCI symbol ( ). All changes to, or proposed
substitutions of, HCIs must be approved by the acquiring activity.

7 ELECTROSTATIC DISCHARGE SENSITIVE ITEMS.

All ESDS parts shall be handled in accordance with the ESDS device handling procedures in TO 00-25-234.
Failure to comply could result in damage to, or destruction of, equipment or loss of mission effectiveness.

If included, items containing ESDS parts are marked with the ESDS symbol ( ).

8 IMPROVEMENT REPORTS.

Recommended changes to this manual shall be submitted in accordance with TO 00-5-1.

ix/(x blank)
 TO 35-1-3

SAFETY SUMMARY
1 GENERAL SAFETY INSTRUCTIONS.

This manual describes physical and/or chemical processes which may cause injury or death to personnel, or damage to
equipment, if not properly followed. This safety summary includes general safety precautions and instructions that must be
understood and applied during operation and maintenance to ensure personnel safety and protection of equipment. Prior to
performing any specific task, the WARNINGs, CAUTIONs, and NOTEs included in that task shall be reviewed and under-
stood. The safety precautions in Air Force Instructions (AFI) 91-203 and Occupational Safety and Health Administration
(OSHA) Standard 1910.107 are applicable to the operation of paint shops and spray-painting equipment and shall be followed
during cleaning and repainting of Support Equipment (SE).

2 WARNINGS, CAUTIONS, AND NOTES.

WARNINGs and CAUTIONs are used in this manual to highlight operating or maintenance procedures, practices, conditions,
or statements which are considered essential to protection of personnel (WARNING) or equipment (CAUTION). WARNINGs
and CAUTIONs immediately precede the step or procedure to which they apply. WARNINGs and CAUTIONs consist of four
parts: heading (WARNING, CAUTION, or icon), a statement of the hazard, minimum precautions, and possible results if
disregarded. NOTEs are used in this manual to highlight operating or maintenance procedures, practices, conditions, or
statements which are not essential to protection of personnel or equipment. NOTEs may precede or follow the step or
procedure, depending upon the information to be highlighted. The headings used and their definitions are as follows:

Highlights an essential operating or maintenance procedure, practice, condition, statement, etc., which if not strictly
observed, could result in injury to, or death of, personnel or long term health hazards. Failure to comply could
result in injury to, or death of, personnel or long term health hazards.

Highlights an essential operating or maintenance procedure, practice, condition, statement, etc., which if not strictly
observed, could result in damage to, or destruction of, equipment or loss of mission effectiveness. Failure to comply
could result in damage to, or destruction of, equipment or loss of mission effectiveness.

NOTE

Highlights an essential operating or maintenance procedure, condition, or statement.

3 MATERIALS HANDLING.

3.1 Personnel Hazards. Many of the materials and procedures outlined in this technical order are potentially hazardous to
personnel, if used improperly. When using chemicals such as paint strippers, cleaning compounds, conversion coatings, and
solvents, follow the correct procedures and wear appropriate protective gear to prevent injury to personnel. Read the appropri-
ate Safety Data Sheet (SDS), manufacturer’s instructions and be familiar with related warnings and cautions in this technical
order prior to using any material. Misuse of certain materials can also damage parts or cause corrosion. Refer to DOD
6050.5-LR, Hazardous Material Information System, FED STD 313, Material Safety Data, Transportation Data, and Disposal
Data for Hazardous Material Furnished to Government Activities, or the appropriate systems command documents for the
handling, storage, and disposal of hazardous materials. When in doubt, contact the local safety office, base bioenvironmental
office, or regional medical center for guidance.

3.2 Environmental Hazards. Many of the materials and procedures outlined in this technical order are also potentially
hazardous to the environment. Wherever possible, methods for preventing pollution, minimizing waste, and using less toxic
materials are given. Consult the base bioenvironmental office for information about the handling, storage, and disposal of
hazardous waste.

xi
TO 35-1-3

4 GENERAL PRECAUTIONS.

The following general safety precautions are not related to any specific procedure and therefore do not appear elsewhere in
this technical manual. These are general safety precautions and instructions people must understand and apply during many
phases of operation and maintenance to ensure personal safety and health and the protection of Air Force property.

4.1 Live Circuits. Operating personnel must observe all safety requirements at all times. Do not replace components or
make adjustments inside equipment with the electrical supply turned on. Under certain conditions, danger may exist even
when the power control is in the off position due to charges retained by capacitors. To avoid injuries, always remove power,
discharge, and ground a circuit before touching it. Adhere to all lock out/tag out requirements.

4.2 Resuscitation. Personnel working with or near dangerous voltage shall be trained in modern methods of resuscitation.
Information and training sources may be obtained from the Director of Base Medical Services.

4.3 Finger Rings/Jewelry. Finger rings have caused many serious injuries. Remove rings, watches and other metallic
objects that may cause shock or burn hazards. Unless specifically allowed by shop safety procedures, remove finger rings
during all maintenance activity.

4.4 Compressed Air. Use of compressed air can create an environment of propelled particles. Do not direct air streams
towards yourself or other personnel. Air pressure shall be reduced to less than 30 Pound Per Square Inch Gauge (PSIG) and
used with effective chip guarding and personal protective equipment.

4.5 Dangerous Pressures. Care must be taken during testing to ensure that all test connections are proper and tight. All
system components must be compatible with applied pressure. Personnel must be protected by a safety shield or located at a
distance sufficient to prevent injury.

5 PERSONAL PROTECTIVE EQUIPMENT (PPE).

If unique local conditions make compliance with the protective clothing or other occupational health requirements specified in
this manual unnecessary or impractical, obtain an evaluation of the operation from the Bioenvironmental Engineer. The
Bioenvironmental Engineer or Base Safety Office will determine the required precautions and approved PPE.

6 CLEANERS/CHEMICALS/PAINTS/PRIMERS.

Some cleaners, chemicals, paints, and primers have adverse effects on skin, eyes, and the respiratory tract. Observe manufac-
turer’s warning labels, Safety Data Sheet (SDS) and other instructions for proper handling, storage, and disposal; and current
safety directives. Use only in authorized areas.

7 ELECTROSTATIC DISCHARGE.

Certain circuit card assemblies and their components will be damaged by seemingly undetectable electrostatic discharge. Care
must be exercised during handling/repair of those items. Use electrostatic discharge precautionary procedures outlined in TO
00-25-234, General Shop Practice Requirements for Repair, Maintenance and Test of Electrical Equipment, and MIL-HDBK-
263, Electrostatic Discharge Control Handbook for Protection of Electrical and Electronic Parts, Assemblies and Equipment.

8 CHEMICAL, BIOLOGICAL AND/OR RADIOLOGICAL CONTAMINATED ASSETS.

Any asset that has been contaminated or potentially contaminated must be identified, marked and decontaminated in accor-
dance with AFMAN 10-2503, Operations in a Chemical, Biological, Radiological, Nuclear, and High-Yield Explosive
(CBRNE) Environment and TO 00-110A-1.

xii
 TO 35-1-3

CHAPTER 1
CORROSION THEORY, IDENTIFICATION, CAUSES AND EFFECTS
1.1 PURPOSE.

The purpose of this chapter is to provide Support Equipment (SE) maintenance personnel with the basic knowledge necessary
to understand the causes of corrosion, identify the different types of corrosion that will in-turn help minimize corrosion
damage through prevention and early detection and treatment. To help prevent corrosion, SE technicians must first need to
understand corrosion causes and effects and be able to recognize there are several types of corrosion with different preventive
measures. This chapter is an introduction to corrosion theory, the causes of corrosion and the factors that influence its
development. The various forms of corrosion and the effect of corrosive environments normally on SE are also described in
this chapter.

1.2 DEFINITION OF CORROSION.

Corrosion is the electrochemical deterioration of a metal because of its chemical reaction with the surrounding environment.
This reaction occurs because of the tendency of metals to return to their naturally occurring states, usually oxide or sulfide
ores. For example, iron in the presence of moisture and air will return to its natural state, iron oxide or rust. Aluminum and
magnesium form corrosion products that are white oxides or hydroxides. When corrosion occurs, water is usually present in
some form (e.g., humidity, moisture, condensation, rain, salt spray, etc.), acting as an electrolyte and reacting chemically with
metal surfaces.

1.3 CHEMICAL DEFINITIONS.

1.3.1 Atom. The smallest unit of an element. There are more than 100 elements, including metals (such as aluminum,
magnesium, iron, nickel, titanium, cadmium, chromium, copper, and carbon) and non-metals (such as hydrogen, oxygen,
sulfur, and chlorine).

1.3.2 Electron. A negatively charged particle much smaller than an atom. An electrical current occurs when electrons are
forced to move through metal conductors. Electrons also flow through water solutions, but only in the presence of ions.

1.3.3 Ions. Atoms or groups of atoms bound together that is either positively or negatively charged. An electrical current
occurs when ions are forced to move through water solutions. Ions cannot move through metal conductors.

1.3.4 Electrolyte. A liquid solution (usually water) containing ions. Salt water is an electrolyte, an aqueous (i.e., water)
solution of sodium ions and chloride ions.

1.4 THEORY OF CORROSION.

A corrosion cell is much like a battery. When a metal corrodes, the metal atoms lose electrons and become metal ions in an
electrolyte solution. The positively charged metal ions can combine with negatively charged ions to form corrosion products,
such as metallic chlorides, oxides, hydroxides, and sulfides. Four conditions must exist before this type of corrosion can
occur.

1.4.1 Anode. A metal must be present that has a tendency to corrode. The corroding metal is known as the anode.

1.4.2 Cathode. A dissimilar conductive material (the cathode) that has less of a tendency to corrode than the anode must
be present. Examples include a different metal, a protected part of the same metal, or conductive plastics/composite.

1.4.3 Electrolyte. A conductive liquid (electrolyte) must connect the anode and cathode so that ions can carry electrical
current between them.

1.4.4 Electrical Path. Electrical contact between the anode and cathode (usually in the form of metal-to-metal contact)
must exist so that electrons can move from the anode, where they are released, to the cathode. Eliminating any one of these
four conditions, illustrated in Figure 1-1, will stop corrosion. For example, a paint film on a metal surface will prevent the
conducting liquid (electrolyte) from connecting the anode and cathode, thereby stopping the electric current. Another example

1-1
TO 35-1-3

is when two connected dissimilar metal parts placed in pure water corrode very slowly because of the lack of ions to conduct
the electric current. In seawater, the corrosion reaction is accelerated by a factor of 1,000 or more.

TO-35-1-3-001

Figure 1-1. Diagram of a Simplified Corrosion Cell and an Example of Raised Corrosion Product

1.5 DEVELOPMENT OF CORROSION.

1.5.1 Corrosion Origination Locations. All corrosive attacks begin on the surface of metals whether it is the inside of a
bolt hole, border of a metal crystal, hand rail interior or bottom of a frame. If allowed to progress, corrosion can penetrate into
and through the metal. When corrosion products form, they often precipitate onto the corroding surface as a powdery or
scaled deposit. Other evidence of corrosion is the bulging/blistering of the metal surfaces. Thin film corrosion forms on
electrical contact points and pins may appear as a tarnish, or powdery deposit on the metal surface.

1.5.2 Corrosion Under Painted Surfaces. Paint coatings can mask the initial stages of corrosion. Because corrosion
products occupy more volume than the original metal, frequently inspect paint surfaces for irregularities such as blisters,
flakes, chips, and lumps.

1-2
 TO 35-1-3

ANODIC (HIGH CORROSION POTENTIAL)

MAGNESIUM ALLOYS
ZINC (PLATE)
BERYLLIUM
BERYLLUM (PLATE)
URANIUM (DEPLETED)
ALUMINUM ALLOYS
INDIUM
TIN (PLATE)
STAINLESS STEEL 430 (ACTIVE)
LEAD
1010 STEEL
CAST IRON
STAINLESS STEEL 410 (ACTIVE)
COPPER (PLATE)
NICKEL (PLATE)
AM 350 (ACTIVE)
CHRONIUM (PLATE)
STAINLESS STEELS 350, 310, 301, 304 (ACTIVE)
STAINLESS STEELS 430, 410 (PASSIVE)
STAINLESS STEELS 13-8, 17-7 PH (ACTIVE)
BRASS, YELLOW, NAVAL
STAINLESS STEEL 316L (ACTIVE)
BRONZE 220
COPPER
STAINLESS STEEL 347 (ACTIVE)
COPPER-NICKEL 715
STAINLESS STEEL 202 (ACTIVE)
MONEL 400
STAINLESS STEEL 201 (ACTIVE)
STAINLESS STEEL 321, 316 (ACTIVE)
STAINLESS STEEL 309, 13-8, 17-7 PH (PASSIVE)
STAINLESS STEEL 304, 301, 321 (PASSIVE)
STAINLESS STEEL 201, 316L (PASSIVE)
STAINLESS STEEL 286 (ACTIVE)
AM355 (ACTIVE)
STAINLESS STEEL 202 (PASSIVE)
CARPENTER 20 (PASSIVE)
AM355 (PASSIVE)
TITANIUM ALLOYS
SILVER
PALLADIUM
GOLD
RHODIUM
PLATINUM
CARBON/GRAPHITE
CATHODIC (LOW CORROSION POTENTIAL)

TO-35-1-3-002

Figure 1-2. Galvanic Series of Metals and Alloys

1-3
TO 35-1-3

1.6 FACTORS INFLUENCING CORROSION.

Both natural and man-made environments cause corrosion of SE. Natural conditions that affect the corrosion process are
moisture, temperature, salt atmospheres, ozone, sand, dust, solar radiation, insects and birds, and microorganisms. Man-made
conditions that affect the corrosion process are industrial pollution, manufacturing operations, storage conditions, and
shipment. By understanding these conditions, maintenance personnel will be better able to prevent SE damage. Factors that
influence metal corrosion and the rate at which it occurs are outlined in Figure 1-2.

1.6.1 Type of Metal. The metals most commonly used in SE construction are aluminum, steel, and to some extent
magnesium. Cadmium, nickel, chromium, and silver are sometimes used as protective plating. Metals have a wide range of
corrosion resistance. The most active metals (i.e., those that tend to lose electrons easily), such as magnesium and aluminum,
corrode easily and are listed at the top of Figure 1-2. The most noble metals (i.e., those that do not lose electrons easily), such
as gold and silver, do not corrode easily and are listed at the bottom of Figure 1-2.

1.6.2 Dissimilar Metal Coupling (Galvanic Corrosion). When two dissimilar metals make electrical contact in the
presence of an electrolyte, the rate at which corrosion occurs depends on the difference in their location on the galvanic scale
(see Figure 1-2). The greater the distance between the metals, the faster corrosion occurs. For example, magnesium corrodes
very quickly when coupled with gold in a humid atmosphere. However, pure aluminum corrodes very slowly, if at all, when in
contact with cadmium. It is essential in the repair of SE that compatible metals and metal fasteners, washers, etc., be selected
for repair and refurbishment processes. If dissimilar metal coupling must occur due to the equipment design or configuration,
contact the appropriate system equipment specialist for the appropriate processes and materials to insulate the incompatible
metals.

1.6.2.1 Graphite or carbon fiber composites are materials which consist of reinforcing fibers in a matrix made of organic
resin, usually epoxy. They are an important class of SE construction materials because of their high strength-to-weight ratios
and high stiffness. Although graphite or carbon/carbon composites appear as a plastic, the graphite material is considered a
metal. Care should be exercised when attaching fasteners through the fibers. Use the appropriate sealant to insulate the
composite from the metal parts.

1.6.2.2 Since carbon is the least active metal in the galvanic series, it will accelerate the corrosion of any metal to which it
is coupled. Insulation, with sealant or other nonconductive coatings, between graphite or carbon epoxy composites and other
metals surfaces or fasteners is necessary to prevent dissimilar metal attack on the attached part.

1.6.3 Anode and Cathode Surface Area. The rate of galvanic corrosion also depends on the size of the parts in contact.
If the surface area of the corroding metal (the anode) is smaller than the surface area of the less active metal (the cathode),
corrosion will be rapid and severe. However, if the corroding metal is larger than the less active metal, corrosion will be slow
and superficial. For example, an aluminum fastener in contact with a relatively nonreactive Monel structure may corrode
severely, while a Monel bracket secured to a large aluminum member would result in a relatively superficial attack on the
aluminum.

1.6.4 Climate. Warm, moist air, typically found in tropical climates, tends to accelerate corrosion because of the higher
concentration of water vapor in the air. Additionally, high temperature environments tend to produce more rapid corrosion
because of accelerated chemical reactions. Conversely, cold dry air, typically found in colder regions of the world, tends to
slow corrosion rates due to less water vapor in the air. Corrosion does not occur in very dry conditions. For this reason,
desiccants or dehumidification systems are placed in, or connected to shipping or storage containers to create very dry local
environments. The equipment’s proposed operational environments and established corrosion prevention and control optimal
design parameters should be considered in SE design and procurement.

1.6.4.1 Desert. Hot, wind-swept deserts create a severe maintenance problem because powdery dust can penetrate even
supposedly sealed components. Typically, desert conditions are thought to have low humidity and rainfall. However, there are
areas of the world considered as desert with high daytime temperatures, moderate to low night time temperatures, high
humidity (in areas such as the Persian Gulf), ultraviolet radiation, and fine dust. These conditions pose the most serious,
destructive elements of the desert climate due to the wide range of conditions experienced daily.

1.6.4.2 Temperate Zones. The temperate or intermediate climate zone encompasses most of the North American and
European continents. These areas at various times of the year may approximate the extremes of polar, desert, or tropical
temperatures and humidity. The temperate zone temperatures range from -25 degrees Fahrenheit (°F) to +59 °F (-32 °Celsius
(C) to +15 °C) in the winter and from +59 °F to +125 °F (+15 °C to +52 °C) in the summer. The Relative Humidity (RH) also
fluctuates between five and 100 percent. The most critical areas are coastal locations, during the warm periods of the year in
which the relative humidity approaches 100 percent RH at night and the air has high concentrations of salt. Moisture from this

1-4
 TO 35-1-3

salt laden air can condense on equipment during early evening and morning hours, thereby causing serious corrosion. Because
of its relatively mild temperatures, the temperate zone is also the most heavily populated. Consequently the smoke, smog,
ozone, and corrosive fumes associated with heavy industry are also found there.

1.6.4.3 Tropics. One of the greatest challenges to SE manufacturing industries is to the design equipment that is protected
from corrosion and deterioration in the continual heat and humidity of tropical climates. Even though they encompass only a
small portion of the earth’s land area, the tropics demand the greatest amount of consideration from the standpoint of
corrosion treatment and control. Relative humidity of up to 100 percent RH at ambient air temperatures of 85 °F (29 °C) and
above create a formidable threat of corrosion. When high humidity and temperature conditions are combined with saltladen
air, the corrosive environment becomes extremely severe. The critical combination of high temperatures, condensation, high
relative humidity, and contaminants such as salt and sand may cause premature structural failure of equipment due to
corrosion. Deterioration of the materials used in electronic equipment may also be accelerated. Thin film corrosion on
electrical contact points and pins act as insulators to electrical current adversely affecting the operations of SE.

1.6.4.3.1 Factors of Influence in Tropical Environments. Tropical environments are noted for long periods of heavy
rainfall, during which 100 inches or more of rain may fall. Extended periods of high heat and humidity contribute to rapid
corrosion of metals, cracking and flaking of rubber and plastic materials, and deterioration of seals. Equipment, whether
stored or in use, requires special protective containers/measures and frequent preventive maintenance. Microorganisms
multiply excessively in tropical environments and attack many non-metallic materials. Many items become covered with fungi
in a matter of hours. Electronic equipment requires special efforts for effective operation in the tropics. Intensive preventive
maintenance and the best possible protective techniques are necessary for SE and their components in tropical environments.

1.6.5 Heat Treatment and Grain Direction. When heat-treated, heavy sections of metals do not cool uniformly because
the metallic grain/crystalline structures tend to vary in chemical composition from one part of the metal to another. This can
cause galvanic corrosion if the metal crystals are more active than another or contain contaminates. Alloys that are fabricated
by rolling, extruding, forging, or pressing have properties that depend highly on the metal grain/crystal direction (parallel to
grain elongation vs. cross grain). For example, exposed end grain corrodes much more easily than flattened elongated
surfaces in sheet stock. This explains why exfoliation occurs at the structural edges or next to countersunk fasteners on certain
types of alloys.

1.6.6 Electrolytes. Electrically conducting solutions are easily formed on metallic surfaces when condensation, salt spray,
rain, or rinse water accumulate. Dirt, salt, and carbon deposits from engine exhaust and engine exhaust gases can combine
with water on wet surfaces thereby increasing the electrical conductivity of the electrolyte and the rate of corrosion. Improper
dilution of cleaning chemicals, combining cleaning compounds together, or the use of unauthorized cleaning material can
cause the cleaning solution to become an electrolyte.

1.6.6.1 Moisture is present in air as a gas (water vapor) or as finely divided droplets of liquid (mist or fog) and often
contains contaminants (such as chlorides, sulfates, and nitrates) that increase its corrosive effects. Moisture will enter all areas
of SE that air can enter. All enclosed areas, that are not hermetically sealed, will allow air to enter and leave as the difference
in pressure between the inside and outside the equipment changes. These pressure differences occur when atmospheric
pressure changes and when the air temperature inside an enclosed area changes. As the surrounding surfaces are heated,
moisture-laden air is drawn into the enclosed area or absorbed in open cell foam. As the air around the equipment cool,
moisture will condense in the enclosed areas and settle in the lowest area of the part. The enclosed areas are often hidden
and/or inaccessible. Moisture is difficult to remove and the subsequent corrosion may be difficult to identify in the early
stages.

1.6.6.2 Salt laden atmospheres pose a continual problem in locations operating near coastal environments. When dissolved
in water, salt solutions form very effective electrolytes. The ocean, which is 3.5 percent to 3.9 percent salt, is the world’s
primary source of salt. Normal sea winds carry from 10 to 100 pounds of sea salt per cubic mile of air. Bases located close to
marine environments are continually exposed to the salt laden atmosphere. Because dissolved salts are strong electrolytes, it is
easy to understand why coastal environments are listed in the moderate to severe corrosion prone categories and require
frequent rinsing and cleaning to remove the salt deposits.

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Figure 1-3. Corrosion Accelerated by Condensed Moisture

1.6.6.3 Condensed moisture will usually evaporate as the surrounding air warms but will leave behind its contaminants
(residues), including salts. This can result in the build-up of soils and salt contamination. Salt-laden condensation may collect
at the lowest surface of the equipment. The lowest surfaces are usually the last to dry. As the condensation continues to collect
at the lowest surfaces the contaminates/electrolytes become more concentrated. Condensed moisture and its contaminants can
also be trapped in close fitting, wettable joints, such as faying surfaces. Some gasket and packing materials will absorb several
times their weight in water and, when heated, can transmit this retained moisture into the sealed area. Moisture can accumu-
late in such areas through successive cycles of warming and cooling and cause corrosion on the interior of the part resulting in
premature structural failure as shown in Figure 1-3.

Figure 1-4. Open Cell Foam and Resulting Corrosion

1.6.6.4 Open cell foam, (see Figure 1-4), is a sponge-like material used mainly for sound suppression and insulation.
Humidity, condensation, rainfall, etc., is absorbed into the foam and ultimately migrates to the mating metal surface to which
it is attached. The absorbed moisture is very slow in drying out and provides the moisture/electrolyte against the metal
surfaces. When possible, open cell foam should not be used. Closed cell types of foam may be suitable substitutes for this
material and will not absorb moisture. If open cell foam is the only material suitable for your needs, prior to installation in the
SE, seal all open cell surfaces and sides of any perforations in the foam with a polysulfide type sealant such as MIL-PRF-
81733. Sealing any tears in the foam or any unsealed sides and edges of the foam will preclude any fluid absorption by the
foam.

1.6.6.5 Airborne industrial pollutants also contribute to the deterioration of nonmetallic materials and severe corrosion of
metals. The most aggressive are: carbon (from internal combustion engine exhaust), nitrates (from agricultural fertilizers),
ozone (from electrical motors and welding operations), sulfur dioxide (from engine exhaust and industrial and ship smoke
stacks), and sulfates (from automobile exhaust).

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1.6.6.6 Sand, dust, and volcanic ash are present in many areas, but particularly in industrial areas where they often contain
a number of tar products, ashes, and soot. Dust is also found in tropical zones with plentiful rainfall and arid zones where
there is little or no rainfall. Sand and dust are extreme problems in deserts because the wind carries dry, powdery sand and
dust. During sandstorms, sand and dust can penetrate sealed equipment and many internal areas of SE. Sand, dust, and
volcanic ash are hygroscopic and can absorb and hold moisture when present on internal or external surfaces of SE or
electronic parts. Dust from volcanic areas contains chlorides and sulfates, dust from desert areas may contain chlorides,
carbonates, and sulfates. These materials are extremely corrosive in the presence of moisture. Although small amounts of sand
or dust may be unnoticed by operating personnel, they may be sufficient to initiate and accelerate corrosion.

Figure 1-5. View of the Results of Microbial Induced Corrosion

1.6.7 Microbial Induced/Influenced Corrosion. Although rarely seen on SE, microbial induced/influenced corrosion, as
the term is used in this manual, includes the aggressive action of bacteria, fungi, or molds that can be found on SE. Microor-
ganisms are nearly everywhere and outnumber all other types of living organisms. Those organisms causing the greatest
corrosion problems are bacteria and fungi. Damage resulting from microbial growth can result from: (1) the tendency of the
growth to hold moisture which then causes corrosion; (2) digestion of the substrate as food for the microorganism; or (3)
corrosion of the surface beneath the growth by secreted corrosive fluids of the action of bacteria, fungi, or molds on a metal
surface, (see Figure 1-5).

1.6.7.1 Bacteria may be either aerobic or anaerobic. Aerobic bacteria require oxygen to live. They can accelerate corrosion
by oxidizing sulfur to produce sulfuric acid or by oxidizing ammonia to produce nitric acid. Bacteria living adjacent to metals
may promote corrosion by depleting the oxygen supply or by releasing metabolic products. Anaerobic bacteria, on the other
hand, can survive only when free oxygen is not present. The metabolism of these bacteria requires them to obtain food sources
by oxidizing inorganic compounds such as iron, sulfur, hydrogen, and carbon monoxide. The resultant chemical reactions
cause corrosion.

1.6.7.2 Microbial attack can be prevented by frequent and thorough cleaning of the affected areas and applying moisture-
proofing coatings to nutrient materials or by drying the interiors of compartments with desiccants. However, some moisture-
proofing coatings are attacked by microorganisms, especially if they are used on contaminated surfaces.

1.6.7.3 When dry, some microorganisms can survive in spore form for long periods and can become active when moisture
is available. When desiccants become saturated and unable to absorb the moisture passing into the affected area, microorgan-
isms can begin to grow. Dirt, dust, and other airborne contaminants are the least recognized contributors to microbial attack.
Unnoticed, small amounts of airborne debris may be sufficient to promote fungal growth.

1.6.8 Mechanical Stress. Manufacturing processes such as machining, forming, welding, or heat treatment can leave
stresses in SE parts. Almost all alloys in SE construction are sensitive to a form of corrosion known as Stress Corrosion
Cracking (SCC). This residual stress causes corrosion to proceed more rapidly in structurally important regions of the part
until failure occurs.

1.6.9 Time. As time goes on, metals naturally tend to corrode. In some cases, the corrosion process occurs at the same rate,
no matter how long the metal has been exposed to the environment. In other cases, corrosion can decrease with time (because
of the barrier formed by corrosion products) or increase (if a barrier to corrosion is being broken down).

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1.6.10 Manufacturing. During the manufacture, assembly, or repair of SE, many factors can cause the introduction of
corrosion. Use of unsuitable materials and improper materials processing can cause corrosion. Shearing or hole-punching
operations on some metal alloys, especially on high-strength aluminum, may create stresses that will lead to corrosion or
provide a slight lip to inhibit complete drainage from an area. Raised edges of the hole-punching operations may cause
incomplete drainage of electrolytes once the panels are installed. Assembly of parts in areas contaminated by fumes or vapors
from adjacent operations may entrap fumes in the equipment, which might lead to future corrosion. Areas without humidity
control may be sources of condensed moisture. Inadequate or nonexistent sealant usage, improper material selection, use of
open cell foam for sound suppression are other causes that contribute to premature structural failure of SE.

1.6.11 Storage. Even traces of corrosive vapor in packages containing SE parts may result in serious corrosion. Moreover,
the natural breathing of packages may introduce moisture into parts and equipment. Decomposed packing materials can emit
corrosive vapors during prolonged storage, which can create serious corrosion of equipment and the parts stored in these
packages.

1.6.12 Degradation of Non-metals. Nonmetallic materials (plastics, elastomers, paints, and adhesives) are not subject to
electrochemical corrosion because ions are not easily formed from nonmetallic elements and the electrical conductivity of
non-metals is extremely low. The degradation of non-metals depends on the chemical make-up of the material and the nature
of the environment. In general, nonmetallic materials used on equipment are selected for their performance properties
(flexibility, transparency, strength, electrical resistance, etc.) and their resistance to heat, impact, abrasion, ultraviolet
radiation, moisture, ozone and other detrimental gases, and operational fluids (such as hydraulic fluid, lube oil, cleaners,
deicing fluids, etc.). However, the use of unauthorized maintenance chemicals and procedures can accelerate degradation and
ultimately lead to material failure resulting in leakage, corrosion, electrical shorts, crazing, and/or mechanical failure.

1.6.13 Preventive Maintenance (PM). PM is probably one of the easiest, most effective, and least expensive means of
preventing corrosion and is the process organization maintenance personnel can control. Each type of corrosion has its own
peculiarities and will require special treatment. However, there is a common four point approach in developing an effective
corrosion prevention and control program. The four point approach consists of (1) the early identification of corrosion, (2) the
early and thorough removal of corrosion and proper treatment of the corroded area (3) the complete removal of electrolytes
through frequent cleaning with approved, properly mixed cleaning compounds, (4) and the application and maintenance
upkeep of effective protective coatings.

1.6.13.1 Corrosion can be minimized by frequent washing because the extent of corrosion depends on the length of time
electrolytes are in contact with metals. If Qualified Product List/Database (QPL/QPD) approved cleaners and additives are
used, frequently cleaning of equipment based or operating in a corrosive environment will reduce the likelihood and severity
of corrosion.

1.6.13.2 Keeping chemical treatments and paint finishes in good condition will minimize corrosion. The degradation of
nonmetallic materials can be minimized by avoiding the use of unauthorized maintenance chemicals, coatings, and proce-
dures.

1.6.13.3 Dedication to proper preventive maintenance practices will maximize equipment reliability and availability.

1.6.13.4 A typical PM program should include personnel trained in corrosion identification, prevention, thorough corrosion
removal, chemical treatment, paint removal, sealing, and repainting. An effective PM program also includes:

• Proper SE washing and cleaning cycle based on the corrosion severity zone the equipment operates in.

• Daily cleaning or wiping down of all exposed unpainted surfaces such as actuating rods of hydraulic cylinders.

• Keeping all drains and drain holes open, and low parts of the SE dry and free of salt deposits.

• Initial use, inspection, and reapplication of the appropriate Corrosion Preventive Compound (CPC) following SE
washing, repairs, and component replacement.

• Early detection and thorough removal of corrosion and replacement of the damaged protective coatings and
sealants.Early detection and thorough removal of corrosion and replacement of the damaged protective coatings and
sealants.

• Sealing gaps, seams, and holes to prevent moisture entry. This is especially important around spot-welded areas.

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• Application/reapplication of sealants, where required, to insulated dissimilar metals or prevent water intrusion
following SE repairs, and component replacements.

• Technician awareness of the importance of corrosion prevention during regular maintenance activities (while
performing daily repairs and maintenance tasks, always look for signs of corrosion or corrosion damage).

• Track causes of initial corrosion to the source and eliminate the source.

1.7 TYPES OF CORROSION.

Corrosion is cataloged and classified in many ways. Occasionally, different names are used for the same type of corrosion.
Common types of corrosion are described below.

Figure 1-6. Example of Uniform Etch

1.7.1 Uniform Etch Corrosion. Uniform etch corrosion results from a direct chemical attack on a metal surface and
involves only the metal surface. On a polished surface, this type of corrosion is first seen as a general dulling or etching of the
surface, and, if the attack continues, the surface becomes rough and possibly frosted in appearance. This type of corrosion
appears uniform because the anodes and cathodes are very small and constantly shift from one area of the surface to another.
An example is the etching of metals by acids or by the use of unapproved or improperly mixed cleaning compounds (see
Figure 1-6). The discoloration or general dulling of metal created by exposure to elevated temperatures is not considered to be
uniform etch corrosion.

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Figure 1-7. Example of Galvanic Corrosion-Steel Hinge Bolted to an Aluminum Door

1.7.2 Galvanic Corrosion. Galvanic corrosion (see Figure 1-7) occurs when different metals are in contact with each other
and an electrolyte (such as salt water). It is usually recognizable by a buildup of corrosion at the joint between the metals. If
two dissimilar metals that are widely separated in Figure 1-2 are in direct electrical contact, galvanic corrosion is probably
occurring. The less corrosion-resistant metal (the higher metal in Figure 1-2) becomes the anode and the more corrosion-
resistant metal (the lower metal in Figure 1-2) becomes the cathode. As stated earlier, the anode will corrode. The farther
apart the metals are in Figure 1-2, the more severe will be the corrosion of the anodic metal if the metals are joined electri-
cally and placed in an electrolyte. In most cases, the galvanic series listed in Figure 1-2 is a good predictor of how metals will
corrode in a galvanic couple. A major factor in galvanic corrosion is the size of the anode and cathode. A small anode in
contact with a large cathode will corrode much more severely than a large anode in contact with a small cathode.

TO-35-1-3-008

Figure 1-8. Example of Pitting Corrosion

1.7.3 Pitting Corrosion. The most common corrosion on aluminum and magnesium alloys is called pitting corrosion (see
Figure 1-8). It is first noticeable as a white or gray powdery deposit, similar to dust, that blotches the surface. When the
deposits are cleaned away, tiny pits or holes can be seen in the surface. Pitting corrosion may also occur in other types of
alloys. The combination of small active anodes to large passive cathodes causes severe pitting. Pitting starts as an advanced
form of uniform etch. It can worsen into very severe corrosion that results in localized and relatively deep holes in the metal.
Pits are isolated holes that can vary in shape and size and usually take several months to a year before they become visible.
Pitting is an extremely destructive and insidious form of corrosion. It causes equipment to fail because of perforation with
very little weight or material loss on the entire structure. It is also difficult to detect because the pits are often covered with
corrosion products. Pitting usually initiates at anodic points on a metal surface such as breaks in protective coatings or films,
scratches, and irregularities that are exposed to an aggressive electrolyte. Even though a pit is slow to initiate, once started, it
will progress at an ever-increasing rate and will tend to undercut the surface as it grows.

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CORROSION CORROSION
BLISTER RUST LAYER BLISTER
ALUMINUM
CLADDING

EXPOSED
END GRAINS
CAPILLARY VOID

INTERGRANULAR
ROLLED-ALUMINUM ALLOY ATTACK
(ELONGATED GRAINS)
(ANODE)
CADIUM-PLATED STEEL
FASTENER
(CATHODE) TO-35-1-3-009

Figure 1-9. Illustration of an Intergranular Corrosion Cell

1.7.4 Intergranular Corrosion. Intergranular corrosion (see Figure 1-9) is an attack on the grain boundaries of the metal.
A highly magnified cross-section of any commercial alloy shows the granular structure of the metal. This consists of quanti-
ties of individual grains, each having a clearly defined boundary that chemically differ from the metal within the grain. The
grain boundaries are frequently anodic (i.e., tend to corrode more easily) to the metal within the grain. When in contact with
an electrolyte, rapid corrosion occurs at the grain boundaries.

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Figure 1-10. Example of Exfoliation Corrosion

1.7.5 Exfoliation Corrosion. Exfoliation corrosion (see Figure 1-10) is an advanced form of intergranular corrosion and
occurs when the surface grains of a metal are lifted up by the force of expanding corrosion products occurring at the metal
grain boundaries. The lifting up or swelling is visible evidence of exfoliation corrosion. Exfoliation occurs on extruded, rolled,
wrought, and forged high strength aluminum and magnesium parts.

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TO-35-1-3-011

Figure 1-11. Examples of Concentration/Crevice Corrosion

WASHER LOW OXYGEN CONCENTRATION

INSIDE CREVICE (ANODE)
CORROSION AT ANODE HIGH OXYGEN CONCENTRATION
INSIDE CREVICE OUTSIDE (CATHODE)

TO-35-1-3-012

Figure 1-12. Example of Exfoliation Corrosion

1.7.6 Concentration/Crevice Corrosion. Crevice corrosion (see Figure 1-11 and Figure 1-12) occurs when the electrolyte
in a crevice has a different concentration than the area adjacent to the crevice. This type of corrosion is also known as
concentration cell corrosion. Electrolyte inside the crevice contains less oxygen and more metal ions than electrolyte just
outside the crevice. As a result, the metal surfaces have different activities, even though they may be part of the same metal,
and corrosion occurs inside the crevice. This form of corrosion often occurs between faying surfaces or when a surface is
covered by a foreign material (such as dirt) or under gaskets, rubber, or plastic tape. The mechanisms involved in crevice
corrosion are very similar to pitting corrosion. Crevice corrosion most often occurs where there are stagnant solutions
(electrolytes) in holes, gasket surfaces, lap joints, under surface deposits (sand, dirt, corrosion products, etc.), and in crevices
under bolt and rivet heads. To become a site for corrosion, a crevice must be wide enough to allow liquid entry but narrow
enough to keep the liquid stagnant. As with pitting, crevice corrosion is slow to start, but once started, progresses at ever
increasing rates (due to various electrochemical factors). Crevice corrosion is also most intense in solutions containing
chlorides (saltwater). Metals susceptible to pitting (stainless steel, aluminum, magnesium) are also susceptible to crevice
corrosion. However, not all metals that are susceptible to crevice corrosion will be susceptible to pitting. Three general types
of crevice corrosion are: Metal ion concentration cells, Oxygen concentration cells, Active-passive cells.

1.7.7 Stress Corrosion Cracking. Stress corrosion cracking is the intergranular cracking of a metal caused by the
combined effects of constant tensile stress (internal or applied) and corrosion. Internal or residual stresses are produced by
cold working, forming, and heat treatment operations during manufacture of a part and remain concealed in the part unless
stress relief operations are used. Other hidden stresses are induced in parts when press or shrink fits are used and when
slightly mismatched parts are clamped together with rivets and bolts. All these stresses add to those caused by applying
normal loads to parts in operation. Metals have threshold stresses below which stress corrosion cracking will not occur. This
threshold stress varies from metal to metal and depends on the characteristics of the stress that is applied. The following
conditions must be present for SCC to occur. The component or structure must be under a tensile stress. This tensile stress
may be provided by an externally applied service load or a residual stress resulting from manufacturing procedures such as
rolling, punching, deep drawing, or welding. The material must also be exposed to an environment that causes SCC. Whereas
all metals will form stress corrosion cracks in some environment under the proper conditions, there is no one environment

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that will cause SCC in all metals. SCC is most prevalent and of the most concern in high strength steels, stainless steels
(mostly in the austenitic group), high strength aluminum alloys (2,000 and 7,000 series), copper-based alloys, and titanium
alloys.

1.7.8 Hydrogen Embrittlement. Hydrogen embrittlement is the weakening of materials such as high-strength steel
(typically 180 Ksi and above), some high-strength aluminum, titanium, and some types of stainless steels when they are
exposed to acidic materials such as acid paint removers, acidic metal pretreatments and cleaners, plating solutions, and some
alkaline materials. This occurs when the materials causes a cathodic reaction on the metal surface that produces hydrogen.
The hydrogen diffuses into the bulk metal, accumulating at grain boundaries and weldments weakening the structure. If the
part is under load or contains residual manufacturing stresses, sudden catastrophic failure occurs when the part can no longer
sustain the internal and/or applied stresses. Hydrogen embrittlement has been known to occur in parts stressed to only 15
percent of nominal tensile strength.

1.7.9 Corrosion Fatigue. Corrosion fatigue is the cracking of metals caused by the combined effects of cyclic stress and
corrosion and is very similar to stress corrosion cracking. If it is in a corrosive environment, no metal is immune to some
reduction in resistance to cyclic stressing. Corrosion fatigue failure occurs in two stages. During the first stage, the combined
action of corrosion and cyclic stress damages the metal by pitting and forming cracks in the pitted area. The second stage is
the continuation of crack propagation, in which the rate of cracking is controlled by. In simplified terms, corrosion fatigue is
mechanical fatigue aggravated by a corrosive environment. In corrosion fatigue, the corrosive environment causes a lowering
or reduction of the fatigue limit (the ability of a metal to resist fatigue cracking) of a metal as it undergoes cycles of stress. In
the absence of a corrosive environment, this same metal would be able to withstand significantly more cycles of stress before
cracking. Corrosion fatigue seems to be most prevalent in environments that cause pitting corrosion.

TO-35-1-3-013

Figure 1-13. Example of Filiform Corrosion

1.7.10 Filiform Corrosion. Filiform corrosion is a special form of oxygen concentration cell corrosion (or crevice
corrosion) that occurs on metal surfaces having an organic coating system. It is recognizable by its characteristic wormlike
trace of corrosion products beneath the paint film (see Figure 1-13). Filiform occurs when the relative humidity of the air is
between 78 percent and 90 percent and when the surface is slightly acidic. It starts at breaks in the coating system (such as
scratches and cracks around fasteners and seams) and proceeds underneath the coating because of the diffusion of water vapor
and oxygen from the air through the coating. Filiform corrosion can attack steel, magnesium, and aluminum surfaces and may
lead to more serious corrosion in some locations. Filiform corrosion can be prevented by: storing equipment in an environ-
ment with a relative humidity below 70 percent; using coating systems with a low rate of diffusion for oxygen and water
vapors; maintaining coatings in good conditions; and washing equipment to remove acidic contaminants from the surface
(such as those created by air pollutants). Filiform corrosion most often occurs in humid environments. Once the humidity
drops below 65 percent, Filiform corrosion stops. When the humidity rises above 95 percent, blisters form rather than
filaments. Filiform corrosion forms mostly on steel, aluminum, magnesium, and zinc.

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LOOSE JOINT
RELATIVE MOVEMENT
CORROSION
PRODUCTS

FRETTED AREAS
(WEAR AND CORROSION)

BEFORE AFTER
EXPOSED
METAL
OXIDE
OXIDE
LAYERS
PARTICLES
TO-35-1-3-014

Figure 1-14. Illustration of a Fretting Corrosion Cell

1.7.11 Fretting Corrosion. Fretting corrosion (see Figure 1-14) is a special form of concentration cell corrosion that
occurs in combination with surface wear. The corrosion products increase the wear of the surface, and the wear exposes
additional bare metal surface to be corroded. The overall effect is greater than the single effects of corrosion and wear added
together. It has the general appearance of galling, in which chunks of metal are torn from the surface with corrosion at the
torn areas or ragged pits. This type of corrosion occurs on faying surfaces of close tolerance and on parts under high pressure
in a corrosive environment when there is slight relative movement of parts (such as that caused by vibration). Fretting
corrosion is normally encountered in heavily loaded static joints that are subject to vibration and that are not sealed to prevent
moisture entry. Fretting corrosion is corrosion that occurs between metals that are under load and subject to vibration and/or
slip. It appears as pits or grooves in the metal surrounded by corrosion products. Fretting corrosion can be very destructive in
that it loosens mated parts and close tolerance fittings that in turn lead to stress or fatigue failures. In the case of iron alloys,
brown to red iron oxide will be visible from the area or interface experiencing fretting corrosion. On aluminum alloys, a black
corrosion product is evident. Fretting corrosion is most commonly found in heavily loaded joints that are subject to vibration
such as press fitted ball bearing races, bolted flanges, fayed surfaces, electrical connections, and riveted areas.

1.8 METALS AFFECTED BY CORROSION.

The characteristics of corrosion on SE metals are summarized in Table 1-1. The following is a discussion of corrosion
characteristics of commonly used metals.

1.8.1 Magnesium. Magnesium alloys are the lightest structural metals used for SE construction. These alloys are highly
susceptible to corrosion, which appears as white, powdery mounds or spots when the metal surface is exposed to the environ-
ment without a protective finish. The normal oxide-carbonate film formed on magnesium alloys does not provide sufficient
corrosion protection even in the mildest environment. The rate of corrosion of a magnesium alloy increases when the alloy is
immersed in water or periodically subjected to moisture. Corrosion may also be accelerated by dissimilar metal couples and
when conductive contaminants are dissolved in water. Corrosion of magnesium alloys can be greatly diminished by the use of
the proper protective finish. Some magnesium parts in use were originally protected by anodizing processes, such as HAE and
DOW 17 coatings. The HAE process can be identified by the brown to mottled gray appearance of the unpainted surface.
DOW 17 coatings have a green to grayish-green color. Electrolytic coatings are thicker than those applied by immersion or
brushing. Electrolytic finishes cannot be restored in the field. Take care to minimize removal of these coatings. At the field
level, corrosion removal and surface pretreatment on magnesium parts should be referred to the Aircraft Structural Mainte-
nance Technicians for repair of the conversion coatings.

1.8.2 Steel. Ferrous (iron) alloys are used to manufacture many components and assemblies in SE and other equipment
such as frames and bodies of trailers, and lesser structural parts such as brackets, racks, and panels. If unprotected, ferrous
alloy surfaces, (with the exception of stainless steels also known as Corrosion Resistant Steel (CRES), corrode easily in the
presence of moisture. Ferrous alloy surfaces are normally painted or plated and painted to prevent corrosion. Corrosion of
steel is easily recognized because the corrosion product is red or black color. When ferrous alloys corrode, a dark corrosion
product usually forms first. When moisture is present, this coating is converted to the common red or black corrosion product.

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Effective sacrificial coatings that prevent corrosion on ferrous alloys are cadmium plating or low hydrogen embrittling zinc
nickel (LHE Zn-Ni) plating per drawing 201027456 (for all steels including high strength steels) or 201427084 (for low
strength steel fasteners). LHE Zn-Ni is an environmentally friendly alternative to cadmium that provides equivalent corrosion
protection for ferrous alloys including high strength steels. When switching from cadmium to LHE Zn-Ni, the LHE Zn-Ni
should be specified with the same Type and Class (thickness) as the original cadmium coating. Paint is often applied over
cadmium or LHE Zn-Ni plated surfaces to provide additional protection. Testing has shown good performance when painting
LHE Zn-Ni coatings with epoxy primers per MIL-PRF-85582 Type I, Class N or MIL-PRF-23377 Type I, Class N, MIL-PRF-
32550, Type I, Form A, Class S, or MIL-DTL-53022, Class L, Type IV.

1.8.3 Aluminum. Aluminum and aluminum alloys are widely used for SE construction. Aluminum is highly anodic, as
evidenced by its position in the galvanic series. However, the formation of a tightly adhering oxide film offers increased
resistance under mild corrosive conditions. Some aluminum parts are protected with an electrochemically applied anodized
coating. Aluminum oxide film on aluminum is a naturally occurring protective film; anodizing increases the thickness of the
oxide film. When this coating is damaged, it can only be partially restored by chemical surface treatment. Avoid unnecessary
destruction of the anodized surface layer during the processing of anodized aluminum.

1.8.3.1 The corrosion product of aluminum is a white to gray powdery material (aluminum oxide or hydroxide), which can
be removed by mechanical polishing or brushing with an abrasive. Aluminum is anodic to most other metals, and, when in
contact with them, galvanic corrosion of the aluminum will occur. Aluminum alloys are subject to pitting, intergranular
corrosion, and stress corrosion cracking. In some cases, the corrosion products of a metal in contact with aluminum are
corrosive to aluminum. Therefore, it is necessary to clean and protect aluminum and its alloys against corrosion.

1.8.3.2 Because pure aluminum is more corrosion-resistant than most alloys, aluminum sheet stock is often covered with a
thin layer of nearly pure aluminum called cladding. Cladding is often removed by harsh treatment with abrasives and tooling,
exposing a more corrodible surface. In such areas, paints and CPCs are especially important. However, in environments where
SE is exposed to salt-laden atmosphere or significant industrial pollutants, all bare aluminum surfaces require protection.

1.8.4 Copper and Copper Alloys. Copper and copper alloys are quite corrosion-resistant, with corrosion usually limited
to staining and tarnish. Generally, such changes in surface conditions are not dangerous and usually do not affect the part.
Copper corrosion is evidenced by the accumulation of blue or blue-green corrosion products. Protective paint coatings are
seldom required because of the inherent resistance of the metal. However, paint finishes may be applied for appearance
purposes. The green patina is merely a thin coating consisting mainly of basic copper sulfate and perhaps some hydrated
copper carbonate. The patina in the thin, firmly adhering state actually offers increased corrosion protection to the base metal,
but the patina in a rough or frosted state should be removed. When coupled with most metals used in SE construction, copper
is the less active metal and greatly accelerates the corrosion of other metals. This is especially true in copper/aluminum
couples. Examples are usually found in electrical components and in areas where copper bonding strips or wires are fastened
to an aluminum chassis or structural components.

1.8.5 Stainless Steel. Stainless steel or CRES, as they are more properly described, are alloys of iron with chromium.
Many other elements such as nickel, sulfur, molybdenum, vanadium, cobalt, columbium, titanium, and aluminum are added in
various amounts and combinations to develop special characteristics. Stainless steels are much more resistant to common
rusting, chemical actions, and high-temperature oxidation than ordinary steels because of the formation of an invisible oxide
film or passive layer on the surface of these alloys. Corrosion and heat-resistance are the major factors in selecting stainless
steels for a specific application. However, it should be emphasized that stainless steels are not a cure for all corrosion
problems because of service conditions that can destroy the oxide film on their surfaces. Stainless steels are highly susceptible
to crevice corrosion and stress corrosion cracking in moist, salt-laden environments. In addition, if proper techniques of
sealing and protective coating are ignored, they can cause galvanic corrosion of almost any other metal with which they are in
contact. Stainless steels may be magnetic or nonmagnetic. Magnetic steels are identified by numbers in the American Iron and
Steel Institute (AISI) as 400-series (such as 410 and 430). These steels are not as corrosion-resistant as nonmagnetic steels,
which are identified by numbers in the AISI 300-series (such as 304 and 316). The AISI 300-series steels have nickel contents
ranging from 6 percent to 22 percent; the 400-series steels have nickel contents of only 2 percent.

1.8.6 Nickel and Chromium. Nickel and chromium are used as protective plating. Chromium plating is also used to
provide a smooth, wear resistant surface and to reclaim worn parts. A nickel undercoat is used for corrosion resistance in a
marine environment. The degree of protection depends on plating thickness. Both of these metals form continuous oxide
coatings that can be polished to a high luster and still protect themselves and any underlying metal. Chromium coatings
contain cracks, and corrosion originates at the base metal below these separations.

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Table 1-1. Corrosion of Metals-Type of Attack and Appearance of Corrosion Products

Alloy Corrosion Susceptibility Appearance of the Corrosion

Magnesium Pitting Rough, white powdery deposits
Low Alloy Steel Surface oxidation, pitting, concentration Reddish-brown or black deposits
cell
Aluminum Alloy Surface oxidation, pitting, intergranular, White to gray powdery deposits
exfoliation, stress corrosion, fatigue, and
fretting, concentration cell
Stainless Steel/CRES (300-400 Series) Crevice corrosion, some pitting in a Rough surface, sometimes a red,
marine environment or water storage brown, or black uniform stain or pits
containers with high chlorine levels,
corrosion cracking intergranular
corrosion (300 series) and surface
corrosion (400 series)
Copper-Base Alloys, Brass, Bronze Surface oxidation, pitting Blue to blue-green powdery deposits
Chrome/Nickel Pitting (promotes rusting of the substrate Usually there are no visible corrosion
steel where the pits in the plating occur). products on the plating surfaces.
Blistering of the plating is due to the
rusting and lifting of the substrate
metal.

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CHAPTER 2
CLEANING
2.1 GENERAL.

2.1.1 Introduction. A well developed cleaning program utilizing approved cleaning materials and processes is a key factor
in reducing the impact of corrosion. Use of untested or unauthorized cleaning materials may cause premature coating system
failure and or accelerated corrosion.

2.1.2 Support Equipment (SE) Wash Cycles.

NOTE

Washing is a critical element of a comprehensive corrosion program which also includes using only qualified
products for washing, painting, and other corrosion prevention processes. This program must include refurbishment
of the equipment prior to deterioration from corrosion, routine touch-up of the coating system, use of Corrosion
Preventive Compounds (CPC) where touch-up cannot be accomplished immediately, and covered storage where
practical.

For the purpose of this chapter SE refers only to powered and non-powered Aerospace Ground Equipment to include
propulsion and munitions handling trailers. However, when unique operational requirements exist for specific equipment, the
wash schedules, corrosion prevention and inspection processes can be extended and called out in the equipment/end-item
specific commodity manual, if approved by the cognizant engineering authority. Corrosion prevention, maintenance inspec-
tion, repair and overhaul addressed in equipment/end-item commodity manuals take precedence over this manual. Major
Command (MAJCOMs) may add additional types of equipment to the wash program. SE must be washed in accordance with
Table 2-1. Wash can be scheduled in conjunction with phase inspection if scheduled within due month. MAJCOMs and local
units may mandate or implement wash intervals more frequently than those reflected in Table 2-1. When determining more
frequent wash cycle intervals, a variety of factors should be considered. If the corrosion protective systems (primers and
topcoats) are in poor condition or are compromised in any way, the coatings have not been touched up, the equipment is
stored outdoors, and/or there is already evidence of corrosion, more frequent washing and/or rinsing is of increased impor-
tance. Where corrosion of this equipment is already a problem, wash cycles even more frequent than 90 days/quarterly is
recommended. If the SE is temporarily assigned to locations where cleaning is not practical, the affected equipment shall be
cleaned, inspected, and lubricated within 30 days of returning to home station. Base locations not listed in Table 2-1 will use
the requirements of the nearest base location unless within 1.25 miles of salt water. Locations within 1.25 miles of salt water
are considered severe and require 90 day wash. Contact Air Force Corrosion Prevention and Control Office (AFCPCO) for
further guidance if needed.

2.1.2.1 War Reserve Materiel (WRM) Support Equipment Wash Exemption Waivers. In accordance with Air Force
Instructions (AFI) 21-101, acceptance inspections are required for newly assigned SE. During acceptance inspections, the
equipment’s corrosion condition will be evaluated and scored in accordance with Paragraph 3.3.1.2 of this technical order. All
newly assigned WRM SE must be cleaned/washed prior to storage. Afterwards, in accordance with this chapter’s instructions,
minimum wash intervals must comply with Table 2-1 requirements.

2.1.2.2 The wash interval for WRM SE (Use Code D) located at a SEVERE location (see Table 2-1) and stored inside a
fully enclosed facility may be extended from a 90 day interval to a 180 day interval when the following practices and
requirements are met:

• WRM SE removed from a fully enclosed facility for more than two (2) hours in a 24 hour period must be washed
prior to placing the equipment back in the storage facility.

• The facility’s access doors (e.g. rollup doors, hangar doors, etc.) must not exceed four (4) hours of being partially or
fully opened during a 24 hour period. Exceeding the total allowed time of being partially or fully opened during a 24
hour period will result in the stored WRM SE reverting back to its regular wash interval as outlined in Table 2-1.
Wash will be due based on date of last wash.

2-1
TO 35-1-3

• Waiver requests must be coordinated through the respective MAJCOM’s Head Quarters Fabrication and Aerospace
Ground Equipment (AGE) Functional Managers to ensure the facility is qualified and meets all requirements as well
as assessing the overall corrosiveness of the environment and condition of the AGE at the operating base location.

NOTE

• Tropical environments experience long periods of heavy rainfall. Extended periods of high heat and humidity
contribute to rapid corrosion of metals, cracking and flaking of rubber and plastic materials, and deterioration of
seals. Intensive preventive maintenance and the best possible protective techniques are necessary to safeguard
the readiness of SE within tropical environments. Climate/humidity controlled storage facilities greatly enhance
corrosion prevention/control programs and increase the likelihood of operating within this waiver.

• For WRM SE located in MODERATE/MILD locations, waiver requests to extend the wash interval from a 180
day interval to a 365 day interval can be submitted to the respective MAJCOM’s Head Quarters Fabrication and
AGE Functional Managers for review and approval/disapproval.

2.1.3 Definition of Cleaning. Cleaning is a broad term covering methods and materials needed to remove soils from a
surface. Selection of an appropriate cleaning method in any given case depends on three important factors: (1) type and
amount of soil, (2) base material composition and surface condition, and (3) degree of cleanliness required.

2.1.4 Types of Cleaners. Cleaners that are used in this technical manual may be placed in types as follows:

2.1.4.1 Alkaline cleaners remove soil by displacement of the contaminants from the surface rather than by direct solution in
the cleaner. After displacement, the soils may be carried in the body of the cleaner as a suspension; it may separate, or in the
case of fatty soils, it may react partially or completely with the cleaner to form water-soluble soap. Cleaners of this type
usually have components that aid in cleaning by lifting the soils and other contaminants from a surface.

2.1.4.2 Solvent cleaners remove a soil by dissolving the soil and usually leave a thin film or residue of an oily nature.
Removal of this oily film or residue is accomplished by using an alkaline cleaner.

2.1.4.3 Solvent emulsion cleaners remove a soil by emulsifying the oil constituent of the soil and holding it in suspension
until rinsed from the surface with water.

2.1.5 Methods of Cleaning. Methods of cleaning used in this technical manual are four types, as follows:

2.1.5.1 Hand cleaning is commonly used when the parts/equipment cleaning volume of work is too small, or the parts too
large to justify the expense of special equipment. Cleaning solutions may be applied by means of brushes, swabs, or cloths.
Wherever the cleaning materials may be harmful to the skin, personnel shall be supplied with proper safety equipment. Hand
cleaning is time consuming and may use more water than other washing techniques. Pressure washers are normally used;
however, organizations sometimes use Foamers to wash equipment.

2.1.5.2 Spray washing is usually the most-rapid method for cleaning. The chief feature of spray washing is the application
of the mechanical force of the spray in addition to the chemical and physical actions of the cleaning solution. By means of
these combined actions, the soil is rapidly wetted, penetrated, loosened, removed from the surface, and suspended in the
solution in a free-rinsing condition.

2.1.5.3 Immersion in cleaning tanks is usually used for disassembled parts submerged in an authorized cleaning com-
pound(s). Since the cleaning compounds may act as an electrolyte between two or more metals, care shall be taken not to
intermingle the different metals together in the same cleaning tank.

2.1.5.4 Use of foamers involve injecting air into a tank containing a soap solution, which rapidly mixes the air and solution
as it leaves the tank via a hose. This process produces a very thick, foamy solution that adheres well to the exterior of the SE
allowing the cleaning solution to maintain contact with the surface being cleaned.

2.1.5.4.1 The solution is allowed to dwell on the SE briefly, scrubbed with wash pads or mops, then is rinsed off the SE
with fresh water.

2.1.5.4.2 Detergent can be added at a pre-set and controlled rate when using foamers or pressure washers for SE cleaning.
Therefore, these methods are preferred over hand washing, which cannot regulate the amount of detergent used.

2-2
 TO 35-1-3

Table 2-1. Wash Interval Based on Corrosion Severity Zones

Severe Moderate/Mild
Location (90 days) (180 Days)
Afghanistan (All Locations) X
AJ Taif, SA X
Al Dhafra, UAE X
Al Jouf, SA X
Al Udeid AB, Qatar X
Ali Al Salem, Kuwait X
Allen C. Thompson Fld.; Jackson, MS (ANG) X
Altus AFB, OK (AETC) X
As Sulayyil, SA
Anderson AFB, GU X
Anchorage IAP, AK (ANG) X
Andrews AFB, MD (DC) X
Atlantic City, NJ (ANG) X
Aviano AB, IT X
Bahrain X
Balad X
Bangor IAP, ME (ANG) X
Barksdale AFB; Shreveport, LA X
Barnes M. Apt; Westfield, MA (ANG) X
Battle Creek, MI (ANG) X
Beale AFB; Marysville, CA X
Boise Air Term., ID (ANG) X
Bradley IAP; Windsor Locks, CT (ANG) X
Brindisi/Casale AB, IT X
Buckley ANGB; Denver, CO (ANG) X
Burlington IAP, VT (ANG) X
Byrd Fld.; Richmond, VA (ANG) X
Camp Lemonnier, Djibouti X
Cannon AFB; Clovis, NM X
Capital Mun. Apt.; Springfield, IL (ANG) X
Channel Island; Port Hueneme NAS, CA (ANG) X
Cheyenne Apt., WY (ANG) X
Charleston AFB, SC X
Charleston Apt., WV (ANG) X
Columbus AFB, MS (AETC) X
Curacao, Netherlands, Antilles X
Danelly Fld.; Montgomery, AL (ANG) X
Davis-Monthan AFB; Tucson, AZ X
Des Moines IAP, IA (ANG) X
Dhahran, SA X
Diego Garcia X
Dobbins ARB; Marietta, GA (AFRC) X
Douglas IAP; Charlotte, NC (ANG) X
Dover AFB, DE X
Duluth IAP, MN (ANG) X
Dyess AFB; Abilene, TX X

2-3
TO 35-1-3

Table 2-1. Wash Interval Based on Corrosion Severity Zones - Continued

Severe Moderate/Mild
Location (90 days) (180 Days)
Eareckson (Shemya) AFB; Aleutian Is., AK X
East WV Reg. Apt; Martinsburg, WV (ANG) X
Edwards AFB; Rosamond, CA X
Eglin AFB; Valparaiso, FL X
Eglin AFB (Aux Fld. #3), FL X
Eielson AFB, AK X
Ellington Fld.; Houston, TX (ANG) X
Ellsworth AFB; Rapid City, SD X
Elmendorf AFB; Anchorage, AK X
Fairchild AFB; Spokane, WA X
Fairford, UK X
Falcon AFB, CO X
Forbes Fld., KS (ANG) X
Fort Smith Mun. Spt., AR (ANG) X
Fort Wayne Apt., IN (ANG) X
Francis E. Warren AFB; Cheyenne, WY (ANG) X
Fresno Air Term., CA (ANG) X
Geilenkhirchen, GE X
Gen. Mitchell IAP.; Milwaukee, WI (ANG) X
Grand Folks AFB; Emarado, ND X
Great Falls IAP, MT (ANG) X
Greater Peoria Apt., IL (ANG) X
Griffiss AFB; Rome, NY X
Grissom ARB; Peru, IN (AFRC) X
Hancock IAP; Syracuse, NY (ANG) X
Hanscom AFB; Bedford, MA X
Harrisburg IAP, PA (ANG) X
Hector IAP; Fargo, ND (ANG) X
Hickam AFB; Honolulu, HI X
Hill AFB; Ogden, UT X
Holloman AFB; Alamogordo, NM X
Homestead AFB, FL (AFRC) X
Howard AB, Panama X
Hulman Reg. Apt., IN (ANG) X
Hurlburt Fld.; Fort Walton Beach, FL X
Incirlick AB, Turkey X
Istres AB, France X
Jacksonville IAP, FL (ANG) X
Jeddah, SA X
Joe Foss Fld.; Sioux Falls, SD (ANG) X
Kadena AB, Japan X
Keesler AFB; Biloxi, MS X
Key Fld.; Meridian, MS (ANG) X
Khamis Mushay, SA X
Khandahar, Afghanistan X
Kiruk, Iraq X

2-4
 TO 35-1-3

Table 2-1. Wash Interval Based on Corrosion Severity Zones - Continued

Severe Moderate/Mild
Location (90 days) (180 Days)
King Khalid, SA X
Kingsley Fld.; Klamoth Falls IAP, OR (ANG) X
Kirtland AFB; Albuquerque, NM X
Fort Kutaka Army Base, AZ X
Kunsan AB; S. Korea X
Lackland AFB, TX X
Lajes Fld.; Azores, Portugal X
Lambert Fld.; St. Louis IAP, MO (ANG) X
Langley AFB; Hampton, VA X
Larnaka International Apt., Cyprus X
Laughlin AFB; Del Rio, TX X
Lincoln Mun. Apt, NE (ANG) X
Little Rock AFB, AR (AETC & ANG) X
Luke AFB; Glendale, AZ X
MacDill AFB; Tampa, FL X
Malmstrom AFB; Great Falls, MT X
Manas, Kyrgystan X
Mansfield Lahm Apt., OH (ANG) X
Mantas, Ecuador X
March ARB; Riverside, CA (AFRC & ANG) X
Martin St. Apt.; Baltimore, MD (ANG) X
Maxwell AFB; Montgomery, AL X
McChord AFB; Tacoma, WA X
McConnell AFB; Wichita, KS X
McEntire ANGB; Columbia, SC (ANG) X
McGhee Tyson Apt; Alcoa, TN (ANG) X
McGuire AFB; Wrightstown, NJ X
McMurdo Station, Antarctica X
Memphis IAP, TN (ANG) X
Minot AFB, ND X
Minn.-St. Paul IAP, MN (ARFC & ANG) X
Misawa AB, Japan X
Moffett Fld., CA (ANG) X
Moody AFB; Valdosta, GA (AETC) X
Moron AB, Spain X
Mountain Home AFB; Boise, ID X
NAS Fort Worth, TX (ANG & AFRC) X
NAS Keflavik, Iceland X
NAS New Orleans, LA (ANG & AFRC) X
NAS Rota; Rota, Spain X
NAS Sigonella; Sicily, Italy X
NAS Souda Bay (Chania Apt.), Crete X
Nashville Met. Apt, TN (ANG) X
Nellis AFB; Las Vegas, NV X
Newburgh Apt., NY (ANG) X
New Castle Co. Apt.; Wilmington, DE (ANG) X

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TO 35-1-3

Table 2-1. Wash Interval Based on Corrosion Severity Zones - Continued

Severe Moderate/Mild
Location (90 days) (180 Days)
Niagara Falls IAP, NY (AFRC & ANG) X
Offutt AFB; Omaha, NE X
O’Hare IAP; Chicago, IL (AFRC) X
Osan AB; S. Korea X
Otis ANGB; Falmouth, MA (ANG) X
Patrick AFB; Cocoa Beach, FL X
Pease ANGB; Portsmouth, NH (ANG) X
Peterson AFB; Colorado Springs, CO X
Pittsburgh IAP, PA (AFRC & ANG) X
Pope AFB; Fayetteville, NC X
Portland IAP, OR (ANG) X
Prince Sultan AB; Al Kharj, SA X
Puerto Rico IAP/ Muniz ANGB; San Juan X
Quonset St. Apt; Providence, RI (ANG) X
RAF Akrotiri, Cyprus X
RAF Lakenheath, UK X
RAF Mildenhall, UK X
Ramstein AB, GE X
Randolph AFB; San Antonio, TX (AETC) X
Reno/Tahoe IAP, NV (ANG) X
Rhein-Main, GE X
Richenbacker IAP; Columbus, OS (ANG) X
Riyadh, SA X
Robins AFB; Warner Robins, GA X
Rosecrans Mem. Apt.; St. Joseph, MO (ANG) X
Salt Lake City IAP, UT (ANG) X
Schenectady Co. Apt., NY (ANG) X
Scott AFB; Belleville, IL X
Selfridge ANGB; Mount Clemens, MI (ANG) X
Seymour Johnson AFB; Goldsboro, NC X
Shaw AFB; Sumter, SC X
Sheppard AFB; Wichita Falls, TX (AETC) X
Sioux Gateway Apt.; Sioux City, IA (ANG) X
Sky Harbor Apt.; Phoenix, AZ (ANG) X
Spangdahelm AF, GE X
Springfield-Bleckley Mun. Apt., OH (ANG) X
Standiford Fld. IAP; Louisville, KY (ANG) X
Suffolk Co. Apt., NY (ANG) X
Tabuk, SA X
Taegu, S. Korea X
Talil, Iraq X
Thumrait, Oman X
Tinker AFB; Oklahoma City, OK X
Toledo Exp. Apt.; Swanton, OH (ANG) X
Travis AFB; Fairfield, CA X
Travis Fld.; Savannah, GA (ANG) X

2-6
 TO 35-1-3

Table 2-1. Wash Interval Based on Corrosion Severity Zones - Continued

Severe Moderate/Mild
Location (90 days) (180 Days)
Truax Fld./ Dane City Reg. Apt.; Madison, WI (ANG) X
Tuscon IAP, AZ (ANG) X
Tulsa IAP, OK (ANG) X
Tyndall AFB; Panama City, FL X
Utapao IAP, Thailand X
Vance AFB; Enid, OK (AETC) X
Vandenberg AFB; Lompoc, CA X
Westover AFB; Chicopee, MA (AFRC) X
Whiteman AFB; Knobnoster, MO X
Willow Grove ARS; Philadelphia, PA (AFRC & ANG) X
Will Rogers IAP; Oklahoma City, OK (ANG) X
Wright-Patterson AFB; Dayton, OH X
Yeager Apt.; Charlesron, WV (ANG) X
Yokota AB, Japan X
Youngstown-Warren Reg. Apt.; ARS, OH (AFRC) X

2.1.6 Cleaning Materials. An effective cleaning program significantly reduces the adverse impact of corrosion. The
cleaning program includes the selection of authorized cleaning materials, mixed in the proper ratio for the surface to be
cleaned, properly applied, and removed.

2.1.6.1 Material compatibility is a key element in a cleaning program. Cleaning material composition and surface condition
affect the methods and materials to be used in cleaning. Certain nonferrous metals, such as zinc and aluminum, present
special problems because heavy-duty alkaline or strong acid cleaners attack the metal. Roughness of surface tends to hold a
soil, thereby making it harder to remove.

Selection and use of unapproved cleaning compounds or approved cleaning compounds improperly diluted may
cause damage to the components or painted surfaces. Each cleaner has specific uses, and must be carefully used to
prevent personal injury or damage to equipment. Only use authorized cleaners that are listed on the Qualified
Product List/Database (QPL/QPD) for a specific specification. Also, ensure all cleaning compounds are properly
diluted for the types soils to be cleaned. Failure to comply could result in damage to, or destruction of, equipment
or loss of mission effectiveness.

NOTE

• A listing of the most current QPL/QPD for a specific cleaning compound can be found on the Defense Logistics
Agency website for specifications, handbooks, and QPL/QPD data (http://assist1.daps.dla.mil/quicksearch.) or
on the Air Force Corrosion Prevention and Control office website located on the Air Force Portal.

• Many of the authorized cleaning compounds are biodegradable in many waste treatment facilities, however some
are not, before purchasing and using a specific product, consult with the base environmental management to
verify that the cleaners can be introduced into the waste water treatment system.

2.1.6.2 Authorized cleaning materials, mixing ratios and cleaning procedures that may be used on SE are shown in Table
2-2. MIL-PRF-87937, Cleaning Compound Aerospace Equipment, is the preferred cleaning compound for SE. However, if
MIL-PRF-87937 is not available, MIL-PRF-85570; Cleaning Compound Aircraft Exterior, may be used. The following is a
brief general description of the different cleaning compounds.

2.1.6.2.1 MIL-PRF-85570, Cleaning Compound Aircraft Exterior, Type I, is for general use on exterior surfaces, and is
effective for use on heavy soils and grease. Type I contain solvents and should not be used in poorly ventilated areas or on
painted lacquer surfaces, unpainted plastic or unpainted composite surfaces.

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TO 35-1-3

2.1.6.2.2 MIL-PRF-85570, Cleaning Compound Aircraft Exterior, Type IA, is the same product as Type I, but is in an
aerosol used for spot cleaning on exterior surfaces. Type IA contains solvents and should not be used in poorly ventilated
areas or on painted lacquer surfaces, unpainted plastic or unpainted composite surfaces.

2.1.6.2.3 MIL-PRF-85570, Cleaning Compound Aircraft Exterior, Type II, does not contain solvents and is used for general
use on exterior and interior surfaces. It is effective on light oils and hydraulic fluids.

2.1.6.2.4 MIL-PRF-85570, Cleaning Compound Aircraft Exterior, Type III, is for use on high gloss surfaces only. It
contains abrasives that remove soils by wearing away the surface that holds the soil. This cleaner will raise the gloss of gloss,
semi-gloss, or flat topcoats. Type III is used to spot clean, and clean engine exhaust areas on gloss finishes.

2.1.6.2.5 MIL-PRF-85570, Cleaning Compound Aircraft Exterior, Type IV, contains solvents, detergents, and suspended
rubber particles. It is a spot cleaner, for use on tactical paint systems. It effectively cleans exhaust tracks, smudges, boot
marks, or other embedded soils. When the cleaning compound containing the rubber particles are rubbed on a soiled surface,
the particles act like tiny erasers and remove soil by entrapping the soil in the rubber particles. This cleaner will not alter the
gloss of a camouflage coating.

2.1.6.2.6 MIL-PRF-85570, Cleaning Compound Aircraft Exterior, Type V, is a low solvent (less than ten percent), gelled
cleaner which can be used to replace solvent cleaning where water rinsing can be allowed, and can be used to clean vertical
surfaces where thin cleaners will run off. To be fully effective, Type V must be applied to a dry surface, do not prerinse the SE
before application of the Type V cleaning compound.

2.1.6.2.7 MIL-C-43616, Cleaning Compound Aircraft Surfaces, Class IA, is an aerosol version of Class I as is very
effective as a spot cleaner. It should not be used where ventilation is poor or on nonpolyurethane paints/markings, vinyl
markings/decals, unpainted/unprotected plastic or composite surfaces.

2.1.6.2.8 MIL-PRF-87937, Cleaning Compound Aerospace Equipment, Type I, is a terpene based solvent emulsion
cleaning for general use on exterior surfaces. It is effective for removing heavy oils, greases and carbon deposits. Suitable for
use on high gloss or tactical paint systems. Type I should not be used in poorly ventilated areas. Do not heat above 115
degrees Fahrenheit (°F). Type I will separate-out oily waste, so the waste can be removed and disposed of while the remainder
of the liquid is sent to a waste treatment facility.

2.1.6.2.9 MIL-PRF-87937, Cleaning Compound Aerospace Equipment, Type III, is a gelled cleaner, and is effective for
cleaning medium to heavily soiled surfaces. May be used on painted or unpainted surfaces where additional dwell time is
desired. It should be used in areas that can tolerate high volumes water rinsing necessary to remove the gelled cleaning
compound. Since the cleaning compound is a gel, it will adhere to vertical surfaces for more effective cleaning. To ensure the
cleaning compound effectiveness, apply the cleaning compound to dry surfaces. Type III will separate-out oily waste,
however, because the cleaning compound is a gel-type material the oil/cleaner separation is difficult to determine unless the
solution sits for several hours.

2.1.6.2.10 MIL-PRF-87937, Cleaning Compound Aerospace Equipment, Type IV, is heavy duty cleaner, effective for
cleaning heavy oils and greases. This material differs from Type I in that it has no flash point. Suitable for use on high gloss or
tactical paint systems. Type IV will separate out oily waste, so the oil can be removed and disposed of while the remainder is
sent to a waste treatment facility.

2.1.6.2.11 MIL-PRF-87937, Cleaning Compound Aerospace Equipment, Types I and IV cleaners may be used in dip tanks
but are not formulated for use in vapor degreasing tanks. The gel-type cleaning compounds are not suitable for dip tank
cleaning operations.

2-8
 TO 35-1-3

Table 2-2. Authorized Cleaning Materials

Type of Soils or
Surfaces To Be Cleaning Mixing Cleaning
Cleaned Material Directions Procedures Comments
Light Soils (Dirt, Dust, MIL-PRF- 1 part cleaner to Apply cleaner solution Best used for general cleaning
Mud, Salt, Loose Soot) 85570, Type I 16 parts water with a foam generator, on painted and unpainted
MIL-PRF- 1 part cleaner to spray, sponge, soft bristle surfaces. Suitable for use on
85570, Type II 9 parts water brush or cloth. Scrub and high gloss or tactical paint
MIL-PRF- 1 part cleaner to then rinse with fresh systems.
87937, Type I 20 parts water water and dry.
MIL-PRF- Undiluted Allow the cleaner to The gel-type cleaning com-
87937, Type III dwell for 1-2 minutes, pound is designed to adhere to
or MIL-PRF- then agitate with a brush vertical surfaces for more
85570, Type V and completely rinse with effective cleaning. The cleaning
water and allow drying. compound contains abrasives
that remove soils by wearing
away the surface that holds the
soil. This cleaner will raise the
gloss of gloss, semi-gloss, or
flat topcoats. The cleaning
compound should be used in
areas that can tolerate high
volumes water rinsing
necessary to remove the gelled
cleaning compound. Do not use
on plastic parts.

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Table 2-2. Authorized Cleaning Materials - Continued

Type of Soils or
Surfaces To Be Cleaning Mixing Cleaning
Cleaned Material Directions Procedures Comments
Moderate to Heavy Soils, MIL-PRF-680, Undiluted Apply with a brush, pad,
Oils Hydraulic Fluid, Type II or III, or cloth and agitate,
Lube Oil, Light Preserva- (CID A-A- repeat until surface
tives and Carbon Buildup 59601) contaminants are removed
from the surface or
suspended in the solvent.
If oily residue is accept-
able, rinse with water and
wipe dry with a clean
cloth. If oily residue is
not acceptable use the
diluted cleaning com-
pounds listed under the
moderate soils section of
this table.
MIL-PRF- Undiluted Allow the cleaner to The gel-type cleaning com-
87937, Type IV dwell for 1-2 minutes, pound is designed to adhere to
or MIL-PRF- then agitate with a brush vertical surfaces for more
85570, Type III and rinse with water. If effective cleaning. The cleaning
the surface is oily or compound contains abrasives
greasy apply the cleaning that remove soils by wearing
compound to the dry away the surface that holds the
surface, allow the soil. This cleaner will raise the
cleaning compound to gloss of gloss, semi-gloss, or
dwell for 5-15 minutes, flat topcoats. The cleaning
then agitate and rinse compound should be used in
with water. Agitate the areas that can tolerate high
area again with a brush volumes water rinsing
and rinse with water to necessary to remove the gelled
completely clean/rinse the cleaning compound. Do not use
area. on plastic parts.
MIL-PRF- 1 part cleaner to Apply with a brush, pad, Has a very high solvent
85570, Type I 9 parts water or cloth and agitate, content. Should not be used
MIL-PRF- 1 part cleaner to repeat until surface where ventilation is poor or on
85570, Type II 4 parts water contaminants are removed nonpolyurethane paints/
MIL-C-43616, 1 part cleaner to from the surface or markings, unprotected plastics
Class I 16 parts water suspended in the solvent. or composite surfaces.
Completely rinse with
clean water. Wipe dry
with a clean cloth.

2-10
 TO 35-1-3

Table 2-2. Authorized Cleaning Materials - Continued

Type of Soils or
Surfaces To Be Cleaning Mixing Cleaning
Cleaned Material Directions Procedures Comments
Heavy Oils, Greases and MIL-PRF-680, Undiluted Apply with a brush, pad, MIL-PRF-680 Type II or III,
Carbonized Exhaust Type II or III or cloth and agitate, also known as Stoddard’s
Deposits repeat until surface Solvent or Dry Cleaning
contaminants are removed Solvent, can be used to clean a
from the surface or variety of soils, particularly
suspended in the solvent. oils, greases and hydraulic
If oily residue is accept- fluids. Type III has a flash point
able, rinse with water and of over 200 °F. MIL-PRF-680
wipe dry with a clean will leave a slight oily residue.
cloth. If oily residue is This is desirable if flash-rusting
not acceptable use the protection is needed. If the part
diluted cleaning com- cleaned with MIL-PRF-680 is
pounds listed under the to be painted or surface
heavy soils section of thisbonding is to occur, wiping the
table. affected surfaces with a lean
cloth dampened with a
nonpetroleum based cleaning
compound, or solvent cleaner
such as Isopropyl Alcohol TTI-
735 or Acetone O-A-51, is
necessary.
MIL-PRF- 1 part cleaner to Wet surface with fresh Solvent emulsion cleaner.
87937, Type I 4 parts water water. Apply cleaning Should not be used in poorly
solution and scrub briskly ventilated areas. Do not heat
with abrasive mat the cleaning compound above
(MIL-A-9962, Type I, 115 °F.
MIL-PRF- 1 part cleaner to Grade A or B). Rinse with Should not be used in poorly
85570, Type I 4 parts water fresh water and dry. ventilated areas or on painted
MIL-PRF- No mixing, this lacquer surfaces, unpainted
85570, Type IA is a premixed plastic or unpainted composite
aerosol surfaces. After cleaning, the
MIL-C-43616, 1 part cleaner to area must be thoroughly rinsed
Class I 4 parts water with water to prevent streaking
or paint deterioration.
MIL-C-43616, No mixing, this
Class IA is a premixed
aerosol
Spot Cleaning-Engine MIL-PRF- Undiluted Type IV: Apply full Do not allow the cleaner to dry
Exhaust Areas 85570, Type IV strength with a non- on the surfaces or rinsing may
or V abrasive cleaning pad. be difficult.
Allow 1 to 3 minutes
dwell time. Scrub with a
circular motion. Rinse
thoroughly, and then dry
with a clean cloth. Do not
allow cleaner to dry on
surface.
Type V: Apply full
strength with brush or
pump spray device. Allow
5 minutes dwell time.
Brush if necessary, then
spray with fresh water to
rinse.

2-11
TO 35-1-3

Table 2-2. Authorized Cleaning Materials - Continued

Type of Soils or
Surfaces To Be Cleaning Mixing Cleaning
Cleaned Material Directions Procedures Comments
Spot Cleaning-Stubborn MIL-PRF- Undiluted Apply full strength with Abrasive spot cleaner for gloss
Soil on Gloss Painted 85570, Type III damp cloth. Allow the surfaces only. This cleaner will
Surfaces cleaner to dwell for 1-2 raise the gloss of gloss,
minutes. Rub with a semi-gloss, or flat topcoats.
circular motion. If the
surface is oily or greasy
apply the cleaning
compound to the dry
surface, allow the
cleaning compound to
dwell for 5-15 minutes,
then agitate and rinse
with water. Rub with a
circular motion and
completely rinse area,
then dry with a clean
cloth. Do not allow
cleaner to dry on surface.
Spot Cleaning-Stubborn MIL-PRF- Undiluted Apply cleaner with a Cleaning compound contains
Soils on Tactical Paint 85570, Type IV nonabrasive cleaning pad. rubber particles that aid in the
Schemes Exhaust Tracks, Allow 1-3 minutes dwell cleaning process. Do not allow
Smudges, Boot Marks, or time. Rub with a circular the cleaner to dry on the
Other Embedded Soils motion. Rinse thoroughly, surfaces or rinsing may be
and then dry. difficult.

2.1.7 General Cleaning Material and Processes. Cleaning compounds facilitate oils, grease, and soil removal.
However, cleaning compounds can damage certain material surfaces and parts if they are improperly diluted and applied.

2.1.7.1 Cleaning Solutions. Using cleaning solutions more concentrated than the manufacturer’s dilution rates are not
acceptable. This action may actually hamper washing operations because concentrated soap solutions tend to make surfaces
slippery, the cleaning solutions will not properly dissolve or lift the contaminants from the surface being cleaned, and can
impede the washing pads from loosening the soils. In addition, concentrated solutions require more rinse water to remove
excess cleaner and may cause paint deterioration or corrosion.

2.1.7.2 Cleaning Compounds. Cleaning compounds may impart biochemical oxygen demand to the washwater and
increase the Potential of Hydrogen (pH). Therefore, use of excessive amounts of cleaning compounds should be avoided.

2.1.7.3 High Pressure Wash/Hot Water Wash Equipment.

• High pressure wash equipment which develops more than 175 Pounds-force per Square Inch (PSI) nozzle
pressure shall not be used to apply cleaning compounds unless specifically authorized by the missile or equip-
ment sulfuric peroxide mix. The use of high pressure can cause damage to metal or composite structures. Failure
to comply could result in damage to, or destruction of, equipment or loss of mission effectiveness.

• High pressure wash equipment shall never be used on components, wheels, and brakes as they can force
lubricants out of bearings and attach points and cause corrosion and wear problems. Failure to comply could
result in damage to, or destruction of, equipment or loss of mission effectiveness.

If approved by the equipment sulfuric peroxide mix, high pressure/hot water wash equipment can be used for general purpose
cleaning of support equipment, and vehicles. Reference Technical Order (TO) 1-1-691 for high pressure wash equipment
information. These machines can deliver four gallon per minute of water and/or cleaning solution at a temperature of 210 °F

2-12
 TO 35-1-3

and a pressure of 3,000 PSI at the attach points on the machine for each output hose. These machines shall be operated per
these instructions and the directions in the specific equipment operating manual.

a. Fill the cleaner reservoir with only approved cleaning compounds.

b. Set the water cleaning compound mixture ratio to fifty parts water to one part cleaner.

c. Use only 40 degrees flat fan spray nozzles.

d. Ensure that the nozzle stand-off distance to the surface is always at least 12 inches and never less.

NOTE

Pressure and temperature at the nozzles will be less than at the hose attach points on the machine due to losses in
the hoses. This equipment may remove any loose sealant and paint.

2.1.7.4 Water Temperature. Hot-water washing breaks the bond between the grease/oil and the SE, flushing away the
grease and oil. Engineering studies have concluded that hotwater washers reduces the cleaning compound usage, as opposed
to cold water washing, by approximately 80 percent, cleaning times by 20 to 75 percent, and potable water usage 30 to 90
percent. Hot water shall be used, when feasible, for SE cleaning operations.

2.1.7.5 Deployed/Remote Sites. At deployed/remote sites, untreated, raw water can significantly impact the levels of
dissolved metals/minerals in the washwater. Raw water could dissolve metals from building and washwater plumbing
systems, including copper from copper pipe, zinc and lead from galvanized pipe, etc. To assist units in deployed locations the
following water quality standards are listed below. Unless an emergency exists, organizations should have the nearest
Department of Defense (DoD) civil engineer assess the water quality standards at the deployed locations prior to the com-
mencement of washing operations. Refer to Chapter 7 for units deploying or returning from Southwest Asia (SWA) environ-
ments.

2.1.7.5.1 Water Assessment. In assessing the site wash water, the key water quality parameters: Potential of Hydrogen,
water hardness, total dissolved solids, and Dissolved Oxygen help assess the corrosivity of the water supply. In general, low
pH (less than 7.0), and hardness (less than 50 milligrams per liter), and high DO content, values approaching saturation,
greatly increase the corrosivity of the water.

2.1.7.5.2 Engines and Engine Components. Engines and engine components are usually washed in a washrack using a
pressurized hot water or steam cleaner. Cleaning compounds may be used in the washing process. Care should be taken to
ensure the forced water and/or steam is not allowed to migrate or be forced into confined areas that would prevent proper
drying as subsequent corrosion could result. A water displacing CPC should be applied as soon as possible after washing to
corrosion prone areas such as piano hinges, behind seals, etc.

2.1.7.6 Water Quality/Recycled Water. Use only clean/fresh potable water for all equipment washing and rinsing
operations. If using closed-loop water recycling systems for washing aircraft, water shall meet the following requirements and
be tested every 30 days to detect any build-up of corrosive salts and/or other contaminants. Any abnormal readings should be
reported to the AFCPCO for waiver consideration.

• Chloride content shall be 400 milligrams per Liter (mg/L) maximum (somewhat higher than
Environmental Protection Agency potable drinking water standard of 250 mg/L).
• pH shall be between 6.5 and 8.5.
• Total dissolved solids content shall be 500 mg/L maximum.
• Total suspended solids content shall be 5 mg/L maximum.
• The Langlier Saturation Index shall be slightly above 0.
• The biological oxygen demand concentration shall be 5 mg/L maximum.
• Adequate disinfection of the water shall be provided to control the growth of microorganisms
in the water.
• The water hardness shall be between 75 and 150 mg/L as CaCO3.
• The total petroleum hydrocarbon content shall be 10 mg/L maximum.

2.1.8 Cleaning of Non-metal Parts Prior to Painting. To ensure proper adhesion between the coating and non-metal part
being painted special consideration must be given to ensure the part is properly prepared for painting.

2-13
TO 35-1-3

2.1.8.1 Composites. Clean with Isopropyl Alcohol, TT-I-735, Acetone, O-A-51, or a solution of one part MIL-PRF-87937
to fifteen parts water.

a. (MIL-PRF-87937 only). Rinse with water or wipe clean with a damp cloth.

b. (MIL-PRF-87937 only). Allow to dry or blow dry with compressed air not to exceed 30 Pounds-force per Square Inch,
Gauge (PSIG).

2.1.8.2 Plastics. Clean with a solution of one part MIL-PRF-87937 to four to fifteen parts water, depending on the soil.
The heavier the soil, the stronger the solution needs to be. MIL-PRF-87937 must be diluted to work effectively.

a. Rinse or wipe clean with a damp cloth.

b. Allow to dry or blow dry with compressed air at less than 30 PSIG.

2.1.9 Cleaning of Electrical Parts. The electrical insulation, wiring, contact pins and components are subject to the
collection of oil, fungus, and dirt. Cleaning can be accomplished as follows:

Do not clean electrical equipment with the power on. There are hazards of personnel being shocked or electrocuted.
Disconnect batteries prior to cleaning electrical generator sets as shorting of switches may cause power to be
applied to system. Failure to comply could result in injury to, or death of, personnel or long term health hazards.

Any solvent must be used with extreme care on insulation and insulated wires, particularly in electric equipment.
Failure to comply could result in damage to, or destruction of, equipment or loss of mission effectiveness.

2.1.9.1 Insulation, wiring and parts shall be cleaned with a clean cloth or sponge and the use of TT-I-735 Isopropyl
Alcohol. Solvents such as dry cleaning fluids, mineral spirits, or paint thinners shall not be used to clean electrical insulation,
insulated wiring and parts because of the injurious affect of these solvents on materials, such as rubber and fiber, and they are
fire hazards.

2.1.9.2 Pins (male contacts) and receiver holes (female contacts) which are contaminated by fungus growth can be cleaned
by wiping with TT-I-735 Isopropyl Alcohol. A clean, lint-free cloth moistened with the solvent should be used to wipe the
pins and a toothpick or pipe cleaner saturated with the solvent should be used to wipe out the holes.

2.1.10 Preparation of SE for Cleaning. The cleaning operation is recommended in planned steps to obtain satisfactory
results. In general, steps to be followed are as follows:

2.1.10.1 To protect against cleaning solution entrapment, lubricate all fittings which will be exposed to wash solutions in
accordance with maintenance manuals or maintenance cards. If fittings do not accept lubrication, replace and lube prior to
wash.

2.1.10.2 Inspect the surface to be cleaned and refer to Table 2-2 to determine the type of cleaning compound and mixing
ratio of cleaning compound that should give the satisfactory cleaning results. From the inspection, determine what areas
should be masked or protected.

2.1.10.3 Protect louvers, scoops and other natural entrapments from the cleaning mixture by masking. Masking tape
AA-883, and/or barrier paper, MIL-PRF-121, can be effectively used for masking purposes.

2.1.10.4 The cleaning solution shall not be allowed to dry on plastics, plate glass, and painted surfaces. The cleaning
solution shall not be applied to large areas that cannot be adequately agitated and thoroughly rinsed before it dries. Streaks
and less effective cleaning will result if mixture dries on the surface being cleaned.

2-14
 TO 35-1-3

2.1.10.5 Outside cleaning will be closely controlled or not done during the warmest part of the day or on windy days, as the
cleaning solution will dry rapidly. Wetting the surface with water before applying the cleaning solution will cool the surface
and help prevent fast drying in hot weather. Cleaning shall be accomplished in shaded areas whenever possible during hot
weather (above 80 °F).

2.1.10.6 Apply the cleaning solution until the area to be cleaned is completely covered.

2.1.10.7 Agitate the compound by scrubbing the surface with a nonmetallic brush. Vigorous scrubbing action with a brush
is not usually required except in extremely soiled areas. Depending on weather conditions, allow approximately five to ten
minutes from application of mixture before rinsing.

NOTE

Do not allow the cleaning mixture to dry on the equipment before rinsing.

2.1.10.8 Thoroughly rinse mixture from the area being cleaned by using large amounts of clean water. Heated water
(approximately 140 °F) will give best results.

NOTE

Water needed for thoroughly rinsing shall be readily available at the surface being cleaned. Streaking (white powder
and surface dulling) will result if the cleaning solution remains on the surface being cleaned too long or dries.

2.1.10.9 If streaking appears, immediate reapplication of the cleaning solution will usually reduce or eliminate this
condition.

2.1.11 Cleaning of Engine Components and Enclosures. Remove carbon from disassembled engine parts with
Specification SAE-AMS-C-19853 cleaning compound. Follow material manufacturer’s instructions on the use of this product.
This is a compound for removing or loosening carbon from engine components by means of immersion at ambient tempera-
tures without agitation. This solution will remove many standard paint finishes. This material shall be used in a tank provided
with a cover and in a well-ventilated area, although a water seal is provided to reduce evaporation and loss of the solvent. The
water seal aids in pre-rinsing, reduces toxicity somewhat, and absorbs a portion of the corroding type contamination intro-
duced when parts are being cleaned.

Carbon remover compound SAE-AMS-C-19853 contains chemical compounds that are hazardous and must be
confined to tank use. Disposal of this compound must be in accordance with state, local, and federal requirements.
Failure to comply could result in damage to, or destruction of, equipment or loss of mission effectiveness.

2.1.11.1 To prevent contamination of carbon remover solution, remove all loose oil, grease and dirt from the parts with
solvent MIL-PRF-680, Type II or III, A-A-59601 or MIL-PRF-32295, Type II.

2.1.11.2 Place parts in a mesh basket, or suspend by wire, and immerse in the lower layer of the solution. Agitation or
excessive mixing of the two layers shall be avoided during cleaning operations.

• Ensure the parts are below the water seal. Do not allow the basket or parts to rest on the bottom of the tank.
Failure to comply could result in damage to, or destruction of, equipment or loss of mission effectiveness.

• Do not intermingle ferrous and nonferrous metal parts in the same immersion tank of carbon remover or other
cleaning compounds as corrosion will likely occur. Failure to comply could result in damage to, or destruction
of, equipment or loss of mission effectiveness.

2.1.11.3 Close the lid of the tank and allow the parts to soak approximately two hours, depending on the hardness and
extent of the deposits to be removed.

2-15
TO 35-1-3

2.1.11.4 Raise the parts slowly, permitting the parts to come in contact with the upper layer for approximately 30 seconds,
then remove from the tank.

2.1.11.5 Rinse parts with hot water under pressure and allow to dry. When heated water is not ready available, cold water
may be used. However, longer rinsing is required with cold water than heated water.

2.1.11.6 If the SAE-AMS-19853 cleaning compound is not available, MIL-PRF-87937, Type I is capable of removing
carbon. Use it in a concentration of two parts water to one part cleaner at ambient temperatures in the tank. Do not allow parts
to remain immersed in the MIL-PRF-87937, Type I for more than four hours without removal and inspecting the parts for
cleanliness. For heavy carbon deposits 16-hour total immersion may be necessary. After immersion, rinse with clean water.

2.2 MECHANICAL CLEANING.

NOTE

Do not blast valve stems or precision-machined parts. All oil ports, passages and coolant passages shall be taped or
plugged to prevent grit or beads from entering.

2.2.1 General Information. For the purposes of this TO, mechanical cleaning consists of sanding, grinding, wire brushing
of the repair areas only or general scuff sanding only. For complete SE chemical or mechanical depainting and/or corrosion
removal using medium pressure water blasting, abrasive media blasting operations to remove coatings and corrosion refer to
TO 1-1-691 for information for advanced corrosion removal and surface treatment and TO 1-1-8 for complete paint removal
and replacement of protective finishes.

2.2.2 Coating Removal on Composite Surfaces.

Paints may contain toxic materials such as chromates, barium, strontium, or lead. Use goggles, gloves, and
cartridge respirator during mechanical cleaning of painted surfaces. Hearing protection and air respirator shall be
worn during plastic media blasting operations as directed by local bioenvironmental engineer. Contact the local
safety and health office for proper Personal Protection Equipment (PPE). Failure to comply could result in injury to,
or death of, personnel or long term health hazards.

• SE personnel assigned to coating removal tasks must be specifically trained for the function to which they are
assigned such as, the use of chemical paint removers, abrasive blasting materials and processes, powered tools,
and damage limitations. Inadequate training will lead to further damage of equipment and poses a safety hazard
to the individual. Failure to comply could result in damage to, or destruction of, equipment or loss of mission
effectiveness.

• For repainting operations, under no circumstances shall the primer be completely removed to expose the
composite material substrate. Damage to surface fibers usually occurs when primer is completely removed.
Failure to comply could result in damage to, or destruction of, equipment or loss of mission effectiveness.

Coatings shall be removed from composites, such as fiberglass, carbon/graphite, and Kevlar® using only mechanical removal
techniques as specified in this chapter, unless specific exceptions are provided in the appropriate maintenance manuals. Due to
the irregularities in composite surfaces, complete removal of the paint and primer can damage fibers in the composite surface
layers. Therefore, paint removal, for the purposes of recoating operations shall not go beyond the initial primer coat.

2.2.2.1 Coatings removed from composite surfaces for the purposes of performing coating repairs shall be performed by
hand sanding or by using an orbital sander. The use of other types of powered sanders is prohibited due to the high potential
for causing laminate damage. Use extreme care during topcoat and primer removal to prevent sanding into the laminate.

2.2.2.2 To scuff sand a composite surface for overcoating only use medium grade (Grade C) abrasive mats (A-A-58054)
without powered tools for scuff sanding of painted composite surfaces. Fine (Grade B) or very fine (Grade A) abrasive mats

2-16
 TO 35-1-3

may be used with an orbital sander. The abrasive mat can be wet with fresh water, or diluted cleaning compounds listed in
Table 2-2 for light soils, to prevent clogging the pad.

2.2.3 Coating Removal on Metallic Surfaces. For areas of several square inches, paint may be removed using abrasive
mats or flap brushes, taking care not to remove underlying metal. Chemical paint removal, may be used for areas larger than
several square inches. Plastic media blasting or medium pressure water blasting, may be used at organizational levels of
maintenance activities and depots to remove paint on equipment with panel skins thicker than 0.0625 inches (16 gauge).

2.2.4 Grinding. Grinding is normally accomplished with motorized grinding equipment and rubberized abrasive wheels,
discs or abrasive belts. Grinding is normally used to remove heavy corrosion by wearing the corrosion away. Care should be
taken with this corrosion removal process as sound metal is also removed with the corrosion product. The basic steps in
grinding are:

2.2.4.1 Protect adjacent components from scale, chips, and corrosion products.

2.2.4.2 If grease or oil is present, clean areas with the appropriate cleaner(s) listed in this TO prior to mechanical removal
operations. Ensure all oil and grease residues are removed before proceeding.

2.2.4.3 Remove paint and corrosion until a corrosion-free surface is reached. Continue grinding to remove coarse irregu-
larities. Use fine abrasive paper to polish the surface to the desired finish.

2.2.4.4 Immediately apply the final protective paint or other corrosion preventive finish.

2.2.5 Wire Brushing.

The use of goggles or face shield is mandatory when using motor driven wire brushes since corrosion particles can
break loose and fly off. Conduct all painting operations only in an approved spray booth equipped with adequate
ventilation and exhaust. Failure to comply could result in injury to, or death of, personnel or long term health
hazards.

Do not use carbon steel or copper wire brushes on aluminum surfaces. Carbon steel or copper particles may
become embedded in the aluminum causing galvanic corrosion to occur. Failure to comply could result in damage
to, or destruction of, equipment or loss of mission effectiveness.

Wire brushing is a mechanical cleaning operation usually accomplished with a hand wire brush or a wire brush mounted on a
motor driven wheel. By using different types of brushes, and various kinds, length, and gages of wire, a wide, range of
mechanical cleaning actions are possible. Wire brushing is used to remove heavy corrosion and imbedded paint or dirt. A
typical wire brushing procedure follows:

2.2.5.1 Protect adjacent components from scale, chips, and corrosion products.

2.2.5.2 If grease or oil is present, clean areas with the appropriate cleaner(s) listed in this TO prior to wire brushing
operations. Ensure all oil and grease residues are removed before proceeding.

2.2.5.3 Remove loose corrosion with a hand scraper or pneumatic tools.

2.2.5.4 Wire brush area to a sound metal subsurface, ensuring all of the corrosion deposits are removed from the corrosion
pits.

2.2.5.5 After mechanical cleaning and rework has been completed, a final surface treatment and/or protective paint finish,
as listed in this TO, shall be applied as soon as possible.

2-17
TO 35-1-3

2.2.6 High-Pressure Water (HPW) Paint Removal Method.

HPW paint removal system can cause severe damage to equipment and injury of personnel if instructions are not
followed properly. Failure to comply could result in damage to, or destruction of, equipment or loss of mission
effectiveness.

HPW (40,000 PSI) paint removal is authorized for use at depot and field-level operations subject to meeting all personnel
training, safety, and technical data requirements. HPW equipment is an excellent method for paint removal from support
equipment. The HPW system can be used with or without blast abrasive such as bicarbonate of soda. These instructions are
not intended to be all-inclusive, but are general guidelines to be used in conjunction with applicable system specific equip-
ment manuals and/or a definitive process order.

2.2.6.1 Authorized HPW Equipment. This removal method requires the use of HPW and may be used with a bicarbonate
of soda injection system with control hoses, and handheld nozzles of various configurations. The injection system shall
consist of a positive feed control system, such as an auger/computer controlled system. Only the equipment listed in Table 2-3
has been approved for Air Force use.

2.2.6.2 Training Requirements. There are several types of training that can be used to properly train personnel in the
proper use and safe operations of the HPW equipment and processes. Regardless of the training method, all personnel shall be
properly trained prior to operating equipment.

2.2.6.2.1 Manufacturer Provided Training. The equipment manufacturer may provide on-site, video, or computer-based
training for the safe operations of the equipment.

2.2.6.2.2 Locally Developed Training. A locally developed training program can be used for general instruction of
equipment operation and safety requirements. This training should include hands-on practical training in HPW paint removal
using all appropriate safety equipment.

2.2.6.3 Personnel and Equipment Preparation Prior to HPW.

• HPW can cause serious personal injury if the nozzles are directed at personnel. Never point the nozzle in the
direction of other personnel. Failure to comply could result in injury to, or death of, personnel or long term
health hazards.

• Water and blast media can create slippery conditions. Walking on top of equipment should be avoided. Use fall
protection and all work stands shall have guardrails in place. Failure to comply could result in injury to, or death
of, personnel or long term health hazards.

Prior to performing the HPW paint removal process, the following measures should be taken to ensure the safety of personnel
and protection of the equipment to be depainted.

a. Defuel and disconnect the battery of the equipment to be depainted.

b. Ensure the SE seams, and crevices are protected from water intrusion/entrapment to prevent corrosion.

c. Remove and protect from the HPW steam, all soft metal/non-metal components such as data plates, copper parts, hoses,
etc.

d. All sources of ignition shall be kept a minimum of 50 feet away from the HPW paint removal process.

e. Personnel involved in the HPW process shall wear as a minimum earplugs, earmuffs, full-face shield, wetweather gear,
water-resistant hood, waterproof shoes, and shin and instep guard assemblies. The skin and instep assembly should be

2-18
 TO 35-1-3

puncture resistant aluminum with a 5-inches wide by 6-inches long instep section attached by a hinge assembly to a shin
section of at least 20-inch length.

2.2.6.4 HPW Paint Removal Operation. HPW paint removal operations can damage equipment and personnel if
instructions and precautions are not followed. Following the requirements below are necessary to prevent damage:

a. The HPW equipment should have the operating parameters of water pressure not to exceed 40,000 PSI; water flow of
2.85 gallon per minute, bicarbonate of soda blast media flow rate 1/4 to 1/2 pound per minute.

b. The nozzle standoff distance should be within the range of 2 to 4 inches from the tip of the nozzle to the working
surface.

c. The angle if incidence between the nozzle and the work surface should be within the range of 40 to 60 degrees from the
surface being stripped.

d. The nozzle should be moved across the surface at a minimum rate of 4 inches every second.

2.2.6.5 Post HPW Paint Removal Cleaning.

Care should be taken in HPW paint removal operations to preclude blasting media intrusion and warpage of
unsupported thin panels. Failure to comply could result in damage to, or destruction of, equipment or loss of
mission effectiveness.

NOTE

HPW paint removal will present a high potential for flash rusting on equipment. Ensure equipment is primed or
treated with a Flash Rust Inhibitor within a maximum of 48 hours after paint removal.

After completing the HPW paint removal process the following steps should be taken to ensure equipment is protected again
flash rust and corrosion:

a. Remove any protective materials.

b. Areas where the coating was shielded from the HPW process should have paint mechanically or chemically removed
per TO 1-1-8.

c. Open, inspect, and flush all areas where blast media may be entrapped with clean, fresh water.

d. The equipment or components should be thoroughly washed in accordance with Chapter 2 of this technical order.

e. Allow the equipment and/or components to thoroughly dry.

f. Prepare equipment and/or components for a coating system or treat with a Flash Rust Inhibitor such as Hold-Tight 102.
Flash Rust inhibitors are temporary rust inhibitors that usually allow an additional 48-hour interval before priming
without flash occurring.

2-19
TO 35-1-3

Table 2-3. Authorized HPW Equipment

National Stock Number Notes

Equipment (NSN)
E75 Electric Unit 4940-01-438-7212 Aqua Miser water only unit, with 75 Horsepower
(Hp) motor; includes rotary gun and 50 feet hose
assembly.
D-115 Diesel Unit 4940-01-451-0022 Aqua Klean Centrifuge Unit, 115 Hp diesel; 40,000
PSI with abrasive injection; includes rotary gun and
50 feet hose assembly.
E25M Electric Unit 4940-01-413-5627 Electric, 25 Hp, Utilities required 30 Standard Cubic
Feet Per Minute at 100 PSI of compressed air, 6
gallon per minute at 45 PSI clean fresh water, 70
amperes service of 460 volts, 60 cycle 3 phase
electricity w/exact feed media controls.
E25M Electric Unit 4940-01-395-9471 Aqua Miser has controls, breaker box, and a
computer to regulate the pressure of bicarbonate of
soda; the computer gives the exact amount continu-
ously without flexuating.
D44 Diesel Unit without Rotating 4940-01-411-9826 Diesel, 44 Hp, without Rotating Gun.
Gun
D44 Diesel Unit 4940-01-413-5629 Diesel, 44 Hp, 16-1/2 gal fuel tank, pressure feed
media system with micro adjusted regulator. Utilities
required 6 gallon per minute at 45 PSI clean fresh
water.
D44 Repair Kit Model 900-500 4940-01-411-9829 Repair Kit for D44 High Pressure Cleaner Unit.
B-25 Electric Unit 4940-01-451-0020 Least Expensive basic Aqua Miser unit. 25 Hp
electric unit without stainless steel enclosure;
includes rotary gun, fan gun and 50 feet hose.
Trailer, Pressure Cleaner 4940-01-413-5602 Over the road trailer with lights to make high
pressure cleaner unit portable.
Rotary Gun Commercial Purchase Contact the manufacturer for part number and
information.
Bicarbonate of Soda Blast Media 5350-01-414-1894 Water, Soluble, Powder Form, 50 pounds bag.
Combo Foot Shin Guard Commercial Purchase Contact HPW equipment vendor directly for part
number and ordering information.

2.2.7 Handheld Laser (HHL). The HHL is a portable Class IV laser system that effectively removes coatings, corrosion,
and significantly reduces the generation of hazardous waste via a process known as ablation. Ablation causes oxidized
substrates and organic-based coatings to go directly from a solid state to gaseous phase where remaining particulates are
vacuumed through the 3-stage HEPA filtration system at the point of contact. When correctly applied to the corrosion/coating
removal and surface preparation processes on AGE, it eliminates the requirement for a respirator, significantly increasing an
Airman’s comfort during use.

2.2.7.1 Prior to considering procurement of an HHL, the Unit shall coordinate with the Installation Laser Safety Officer, the
installation laser safety officer and the Base Bioenvironmental Engineer (BBE). The installation laser safety officer will be
responsible for approving your standard operating procedures, and advising you on your laser safety training program;
templates are available for this in MIL-HDBK-529. The BBE will be responsible for validating PPE requirements and may
elect to do sampling for chromates and other chemical installation laser safety officers during HHL use. Note: The Installation
Laser Safety Officer (ILSO) often works in the BBE flight and may be the BBE flight commander.

2.2.7.2 Use of the HHL requires the following facility requirements:

• 480 volts, 3-phase, 20 amperes, 50 or 60 hertz power with a receptacle compatible with HBL2431 plugs.

• Dry, compressed air (54 PSI maximum).

2-20
 TO 35-1-3

• Dedicated area where all windows, cracks, and other openings that can transmit light must be masked with alumi-
num, protected with qualified laser safety glass, or appropriately covered with properly rated laser safety curtains to
ensure no laser beam transmission.

• Equipment is designed to operate between 40 and 95 °F with up to 95 percent Relative Humidity (RH); lower RH is
desired for efficiency. Units requiring portability should procure a wheeled trailer capable of attaining the same
environmental conditions.

2.2.7.2.1 Ideal use of the HHL is inside of a dedicated room with limited entries. This makes control of the laser much
easier and presents a safer environment to operate the HHL. The area should be clean to prevent injury or contamination of
the laser; a blast media or paint booth may not be appropriate. In the event a dedicated room is not available, laser safety
curtains shall be used to provide an appropriate barrier from laser beam transmission.

2.2.7.2.2 It is essential that facilities are prepared for receipt of a HHL. Any Units interested in procuring a HHL shall
coordinate with the equipment manufacturer prior to installation/use. Failure to have proper facilities and safety equipment
will render the HHL useless until all of these requirements have been met.

2.2.7.3 HHLs are a very unique tool for corrosion and coating removal, and require special training in order to be safely
and effectively utilized. All previous testing, validations, and demonstrations have been conducted by the Product Support
Engineering Division, AFLCMC/EZP to develop these protocols. All HHL inquiries shall be directed to the AFCPCO at
afcorr@us.af.mil.

2.2.7.4 Safety is of utmost importance when using a HHL. Section Chiefs should use discretion in who they allow to be
trained. HHL users should be Airmen with mature judgement who can be relied upon to follow standard operating procedures
and recommended control procedures.

2.2.7.4.1 Appropriate safety measures can be found in MIL-HDBK-529, cleanLASER’s operating manuals, and local
standard operating procedures (where applicable). These requirements for safety shall be adhered to at all times.

2.2.7.5 The cleanLASER 300 W (CL300; NSN: 5860-01-674-6025) and cleanLASER 1,000 W (CL1,000; NSN: 5860-01-
687-7673) have been demonstrated on AGE at multiple locations across the USAF.

Use of the HHLs have not been approved on aircraft parts. Under no circumstance shall an HHL be used on any
aircraft or aircraft part unless specifically referenced in the applicable weapon system TO. Failure to comply could
result in damage to, or destruction of, equipment or loss of mission effectiveness.

2.2.7.5.1 HHLs are not a drop in replacement for other mechanical or chemical corrosion and coating removal methods.
There are some areas where use of the laser may prove more beneficial than others when stripping AGE. Given feedback from
various demonstration sites, the following is a list of areas where the HHL would likely be superior to other chemical or
mechanical stripping methods:

• Spot stripping: Stripping small areas of paint/corrosion prior to touchup.

• Removal of decals: Decals that are fastened using an adhesive backing may come off much more easily after running
the laser across it a few times.

• Weld stripping: AGE with broken welds or welds required to undergo non-destructive inspection on a periodic basis
is easily stripped using the HHLs.

• Removing corrosion: The HHLs, especially the CL1,000, have shown good results in removing corrosion. Paint is
removed at a rate of approx. 2 mils of paint per square foot per minute using the CL1,000.

2.2.7.5.2 Sections primarily focused on large areas of paint removal would likely not benefit from use of the HHLs. This is
due to a slower removal rate when compared to other approved mechanical or chemical methods.

2-21
TO 35-1-3

NOTE
Stripping using the HHL does not require a respirator if the approved vacuum unit (TEKA LFE-301 (NSN:
5860-01-688-0784) or LFE-401) is used, unless mandated by the base BBE. Multiple tests conducted internal and
external to the DoD have shown all contaminant levels are below the Occupational Safety and Health Administra-
tion (OSHA) required operational exposure limits. Thus, use of the HHLs by personnel that are not respirator
certified, e.g., AGE or Metals Technology section personnel, may provide an added logistical benefit by reducing
the transport of AGE to multiple Sections.

2.2.7.6 Use of the HHL shall be in accordance with MIL-HDBK-529. All appropriate operational, maintenance, and safety
information is stated within unless otherwise referenced by the handbook. Any questions or concerns shall be directed to the
AFCPCO per Paragraph 2.2.7.3 of this technical order.

2-22
 TO 35-1-3

CHAPTER 3
PAINTING, SEALING, CORROSION PREVENTIVE COMPOUND
APPLICATION
3.1 GENERAL.

Operators may need to wear respiratory protective equipment when spray painting, or the area may need proper exhaust
ventilation. United States Air Force (USAF) organizations that apply protective coatings will request initial and annual
surveys by the local Bioenvironmental Engineer and Safety Officer. Their recommendations for complying with Air Force
Occupational Safety and Health Standards (AFOSH) will be followed. Contractor personnel will comply with all Bioenviron-
mental Engineer, Safety Officer guidelines and Occupational Safety and Health Administration (OSHA) Standards.

3.1.1 Coating Requirements. Comply with all cited coating requirements in Chapter 3, if a conflict exists, follow the
manufacturer recommendation.

3.2 DEFINITION OF EXPOSURE.

Exposure is defined as Support Equipment (SE) that is subjected to combined direct action of climatic elements (to include
the interior of such units). Climatic elements include temperature extremes, humidity extremes, rain, hail, snow, sleet,
salt-laden air, industrial atmospheres, direct solar radiation, dust and scouring action of wind-blown sand.

3.3 REQUIREMENTS FOR PAINTING-FIELD LEVEL.

NOTE

Flight Chiefs/Superintendents are authorized to make the determination if the unit requires complete repainting.

SE shall be repainted when painted surfaces have become bare or exposed because of paint deterioration or damage, or when
it is determined that the equipment is inadequately protected from corrosion. Repainting of SE for purely cosmetic reasons is
prohibited. SE units will be prioritized through the work flow on a worst first basis as determined by SE Scoring documenta-
tion. Refer to Table 3-2 for SE scoring guidance. All SE receiving a new paint finish will have a contrasting color or black
(color 37038) block of no less than 2-1/2 inches applied to the SE as close as practical to Inside Diameter (ID) plate by the
activity that applied the paint. Stencils or decals may be used for the paint block. Figure 3-1 shows an example of a typical
paint block.

3.3.1 Coating Requirements. Comply with all cited coating requirements in Chapter 3, if a conflict exists, follow the
manufacturer recommendation.

3.3.1.1 Corrosion Control Scoring Program and Complete Repainting Criteria . SE requires a robust corrosion
program to ensure the longevity of the equipment. A system of scoring, prioritizing and scheduling will assist with preserva-
tion and refurbishment.

3.3.1.1.1 Corrosion Scoring. The SE corrosion condition will be scored annually during periodic scheduled maintenance
inspection. This allows prioritization and scheduling with the appropriate corrosion control facility. The SE will be prioritized
and scheduled on a worse first basis. The SE owning work center will score and develop a tracking system to annotate the
scores using categories 1-4 as described in Table 3-2.

3.3.1.1.2 SE will be evaluated to determine an accurate corrosion score. The minimum areas evaluated for deterioration
and corrosion are:

• Panels or component surfaces.

• Framework, sub-frame, chassis, and axles.
• Panel or component edges.
• Welds and spot welded panel seams.
• Fasteners and latches.

3-1
TO 35-1-3

• Attachment points.
Deterioration involves:
• Chipped, peeled or blistered paint on panel surface.
• Visible corrosion (rust, pits, white powdery deposits
or rust leaching from panel seams).
• Cracked coating around welds or fastener heads.
• Cracked, peeled or discolored paint at panel seams.
• Cracked or peeled coating at attachment points.
• Coating deterioration caused by environmental
agents, ultraviolet light, corrosive fluids as evi-
denced by excessive fading or a chalky residue on
panel surfaces.
• Missing coatings over recent weld repairs.

3.3.1.2 Scoring Categories. In order to set the priority of scored equipment, technicians evaluate the unit and place in one
of four categories (Table 3-2) with category 1 being best, requiring no touch-up and category 4 as worst, requiring extensive
disassembly, repair, and refurbishment. Leadership should utilize this tool to determine the priority for induction of worst
first into the refurbishment workflow.

3.3.1.2.1 Complete Repaint Criteria. SE requires complete repainting when the coating system fails. A coating system is
considered failed when over 75 percent of the total exterior surface displays obvious oxidation, bleaching, peeling, cracking,
flaking, etc. When the coating system has failed it will be completely stripped and repainted by qualified personnel in
accordance with the standard paint system in Table 3-1. The corrosion control facility performing the SE repaint (ie, Fabrica-
tion Flight, contractors, depot, etc.) will validate the need for a complete repaint prior to accepting the SE into the corrosion
flow.

3.3.2 Abrasive Blasting. The most effective means of completely depainting and removing corrosion from SE is by
mechanical means such as abrasive blasting using approved abrasive blasting dry media, water blasting, or water blasting with
abrasive grit injected into the water stream. Plastic media blasting is effective in removing coatings and light surface corrosion
from SE but will not effectively remove heavy corrosion Technical Order (TO) 1-1-691, Cleaning and Corrosion Prevention
and Control Aerospace and Non-Aerospace Equipment, and TO 1-1-8, Application and Removal of Organic Coatings,
Aerospace and Non-Aerospace Equipment, provides in depth guidance on abrasive blasting material selection and processes.
Refer to these TOs for the effective development and execution of all SE abrasive blasting corrosion and coating removal
programs.

3.3.2.1 Several coating systems require the complete coating removal and surface preparation to include a white metal or
near white metal surface condition with a minimum of a 2 mil surface profile. This requirement can only be achieved through
abrasive grit blasting or High-Pressure Water (HPW) blasting. Several HPW blasting systems will allow the injection of
abrasive grit into the water stream to achieve the required surface profile. Consult the equipment manufacturer’s data sheet for
additional guidance. Ensure the combination of abrasive grit and medium/HPW will not cause warping or other structural
damage to SE and that this process is environmentally acceptable prior to the requisition of the abrasive blasting equipment.

3.3.2.1.1 Dry Media Abrasive Blasting for Iron and Steel. For complete coating and corrosion removal and surface
preparation to include white metal or near white metal surface condition of iron and steel substrates (other than stainless
steel), 0.063 (16 gauge, US Standard) or thicker, use one of the approved products listed below:

STARBLAST XL Commercial and

DBA Dupont Government Entity
4641 County Rd 230 (CAGE) Code: 9Z037
Starke, FL 32091

3-2
 TO 35-1-3

Starblast CAGE Code: 6K233

Cesco, Inc
7251 Cross Country Rd North
Charleston, SC 29418-3300
Phone: 843-760-3000
http://www.blastandpaint.com

Quickstrip 20-40G Cage Code: 1AM56

US Technologies Corp
4200 Munson St NW
Canton, OH 44718
Phone: 770-254-9449
www.ustechnology.com

Garnet Galaxy (Garnet) Cage Code: L4566

Opta Minerals Inc
407 Parkside Dr.
P.O. Box 260
Waterdown, ON LOR 2HO
Phone: (888) 689-6661
www.optaminerals.com

3.3.2.1.2 Dry Media Abrasive Blasting for Aluminum, Magnesium, Stainless Steel and Iron and Steel Less Than
0.063. For complete coating and corrosion removal and surface preparation to include white metal or near white metal
surface condition of aluminum, magnesium, stainless steel alloys and for iron and steel substrates less than 0.063, use
abrasive blasting dry media qualified to MIL-PRF-9954 (reference Table A-1).

3.3.2.2 Medium Pressure Water Blasting. Medium pressure water blasting, with operating pressures less than 40,000
Pounds-force per Square Inch (PSI) is also authorized for coating removal on SE. All requirements and safety considerations
listed in abrasive blasting sections of TO 1-1-691 and TO 1-1-8 apply. Ensure the SE seams, and crevices are protected from
water intrusion/entrapment to prevent subsequent corrosion. Remove or protect from the HPW stream, all soft metal/non-
metal components such as data plates, copper parts, hoses, etc.

3.3.2.2.1 The use of the optional variable speed drive for the medium pressure water blasting units is required if abrasive
media will be introduced into the pressurized water stream.

• Care should be taken in coating removal preparation with all pressurize coating/corrosion removal processes to
preclude blasting media intrusion and warpage of unsupported thin panels. Failure to comply could result in
damage to, or destruction of, equipment or loss of mission effectiveness.

• Water blasting of equipment that has been primed with a chromate containing primer may allow leaching of the
chromate into the waste water. Organizations shall gain approval from the appropriate environmental manage-
ment office of primary responsibility prior to the commencement of water blasting activities. Failure to comply
could result in damage to, or destruction of, equipment or loss of mission effectiveness.

3.3.2.2.2 Use the lowest effective water pressure when removing paint or when abrasive media is used in combination with
the medium pressure water to remove corrosion.

3.3.2.3 Scuff Sand and Overcoat. If disassembly and complete mechanical removal is impractical within the organiza-
tion, due to environmental constraints, the requirements of Table 3-1 for mechanical removal and application of the two layer
metal-rich primer (MIL-PRF-32550)/intermediate primer (MIL-DTL-53030), on ferrous alloys waived and replaced with
MIL-DTL-53022, Type II Aluminum, fiberglass, and stainless steel equipment and parts will not be coated with metal-rich
primers at any time.

3-3
TO 35-1-3

3.3.2.3.1 Unless otherwise directed, bare aluminum parts and equipment shall be primed with MIL-PRF-23377, Type I,
Class N or MIL-DTL-53022, Class L, Type IV.

3.3.2.3.2 All equipment receiving the scuff sand and overcoat type of maintenance painting, where bare metal is not
exposed, may use the listed non-chromated tie-coats over existing MIL-PRF-85285 paint systems:

• MIL-PRF-23377, Type I, Class N

• MIL-DTL-53022, Class L, Type IV

• MIL-DTL-53030

• 8010-01-482-8620, Aeroglaze 9741 (light gray) U/I Kit

• 8010-01-483-4363, Aeroglaze 9743 (red) U/I Kit

• 8010-01-483-4365, Aeroglaze 9744 (dark gray) U/I Kit

• Part Number (PN) 02GN093, Rare Earth Conversion Coating (RECC), Chrome Free, Epoxy Primer U/I Kit

3.3.2.3.3 Preparation and Priming of Plastic Components/Panels. Plastic components/panels should be prepared and
coated as follows:

NOTE

• All contaminates must be removed prior to sanding to prevent embedment of contaminates into the plastic
surfaces.

• Do not use water-borne primers on plastic components. The solvent will allow the primer to bond to the plastic.

• Do not use sandpaper coarser than 240 grit, as it can damage the plastic surfaces.

a. Clean with properly diluted MIL-PRF-87937/MIL-PRF-85570 cleaning compound in accordance with TO 1-1-691.

b. Scuff sand with 240 grit sandpaper to remove coating imperfections, taking care not to sand into the component
substrate.

c. Wipe with solvent thinner MIL-T-81772, Types I, II or III, in accordance with TO 1-1-8.

d. Apply a non-chromated primer (tie-coat) listed in Paragraph 3.3.2.3.2, excluding MIL-DTL-53030.

e. Apply MIL-PRF-85285, Type IV, topcoat in accordance with TO 1-1-8.

3.3.3 Temporary Coating Repairs. For temporary repairs of chipped paint and mild to moderate corrosion, use the
appropriate Corrosion Preventive Compound (CPC) listed in Paragraph 3.13. For severe corrosion that cannot be permanently
repaired the use of rust converters is recommended. For more permanent repairs of small chipped areas, use authorized
coating systems that are contained in items such as but not limited to: SEMPENS, Preval compressed air spray packs,
Clip-Pacs, Brush and Roller, or AKZO Nobel Two-Component MIL-PRF-85285 Aerosol can. Single component aerosols,
enamels or laquers are not authorized coatings. Information about these materials can be viewed on the Air Force Corrosion
Prevention and Control Office (AFCPCO) website on the AF Portal Larger defects in paint or damaged areas will be grounds
to repaint the complete section as determined by Flight Chief or Superintendent.

3.3.3.1 Rust Converters. Rust converters typically consist of mixtures of phosphoric acid, organic alcohols, and tannates
in a latex matrix that forms a protective film on the metal surface that protects against rust. They are designed to be applied
directly to rusty surfaces to convert residual rust on steel surfaces to harmless and adherent chemical compounds. Unlike the
standard scrape, prime, and paint regime, the surface does not require stripping to bare metal. Rust converters, topcoated with
MIL-PRF-85285, serve as a 180-day temporary repair.

3.3.3.1.1 Recommended Rust Converter Products:

3-4
 TO 35-1-3

Neutra-Rust 661
8030-01-369-4416
8030-01-369-4417

Rust Trapper
Image 2,000 (order by product Name)
PO Box 753
Ione, CA 95640

Rust Reformer (Rust-Oleum)

11 Hawthorn Parkway
Vernon Hills, IL 60061

Extend (Loctite)
32150 Just Imagine Drive
Avon, OH 44011

VpCI CorVerter (Cortec)

4119 White Bear Parkway
Saint Paul, MN 55110-7632

3.3.3.1.2 Lightly abrade the surface with a Scotch-brite pad, wire brush, sandpaper, or other equivalent material to remove
loose rust only, leave adherent rust on surface; gently wipe abraded area with towel or cloth to remove dust and debris. Apply
the rust converter in accordance with manufacturer’s instructions. Apply a second coat if required.

3.3.3.1.3 After the rust converter has cured per the manufacturer’s instruction apply a MIL-PRF-85285, Type IV, topcoat.
Repair area utilizing standard maintenance painting procedures as soon as possible.

3.3.4 Touch-up Primer. If steel surfaces on SE requires scuff sanding and overcoating, and the prepared surface is exposed,
bare metal, a metal-rich primer MIL-PRF-32250, Type I, Form A, Class S, or MIL-DTL-53022, Class L, Type IV primer shall
be utilized. If the prepared surface is not exposed, bare metal, a tie-coat primer in accordance with Paragraph 3.3.2.3.2 shall
be utilized.

3.4 REQUIREMENTS FOR PAINTING-DEPOT LEVEL AND CONTRACTOR SUPPORT.

3.4.1 Coating Requirements. Comply with all cited coating requirements in Chapter 3, if a conflict exists, follow the
manufacturer recommendation.

3.4.1.1 Corrosion Rework Determination. The extent of rework to be accomplished during overhaul will be determined
by the Repair Contract. The decision on extent of corrosion repair will be determined by the government quality assurance
personnel utilizing the requirements of this technical order.

3.4.1.2 When it is determined that corrosion is a significant factor, and total repaint of the unit is within economic repair,
then disassembly, abrasive blasting, proper conversion coating of the substrate metals and application of the preferred paint
system described in Table 3-1 will be accomplished. The lack of conversion coating capability or abrasive blasting capability,
by a contractor shall not grant authority to deviate from the requirements.

3.4.1.3 When it is determined that corrosion is not a significant factor, or the units are not within economic repair limits,
then paint touch-up will be accomplished. The paint material used in the touch-up should be the same material that is on the
equipment unless otherwise specified. If the SE requires scuff sanding and overcoating and the prepared surface is not
exposed to bare metal, the use of non-chrome tie coat in lieu of a primer is authorized.

3.4.2 Contractor Compliance. If contractor supported corrosion prevention and control is utilized, compliance with the
proper coating cleaning, surface preparation, preservation, pretreatment, and painting requirements of this manual, TO
1-1-691, and TO 1-1-8 shall be included in the contractors’ Statement of Work.

3-5
TO 35-1-3

3.5 AUTHORIZED COLORS, SEMPENS, AND MATERIALS.

3.5.1 SE Standardized Colors.

NOTE
It is possible to have slight variances in color. Equipment will not be repainted so as to have all equipment or
components the same shade.

The Air Force has instituted a tone down program for SE. The standard color for all flight line SE is SAE-AMS-STD-595,
gray number 26173, MIL-PRF-85285 Type IV, topcoat. The color change shall be integrated into the units’ regular corrosion
schedule and equipment will be aligned with the new scheme on an attrition basis. Newly manufactured, Commercial Off the
Shelf , or refurbished equipment shall be painted gray number 26173, in a MIL-PRF-85285, Type IV topcoat. Flight line
support equipment being deployed to Southwest Asia will no longer be required to be painted tan. Mobile communication
equipment will maintain its current color scheme to meet mission needs/requirements. The authorized colors for mobile
communications equipment are SAE-AMS-STD-595, green color number 24052/34052, light tan number 33303, tan color
number 30279, and brown number 20400, all MIL-PRF-85285, Type IV topcoat. This guidance does not apply to Basic
Expeditionary Airfield Resources SE. All Basic Expeditionary Airfield Resources SE shall be painted SAE-AMS-STD-595,
tan color number 33446, in a MIL-PRF-85285, Type IV topcoat.

3.5.1.1 SE metalized with 85/15 percent zinc/aluminum will remain in the original gray color without a topcoat applied.

3.5.2 SE Standard Topcoat. High solids polyurethane MIL-PRF-85285, Type IV is the required topcoat material for all
SE.

3.5.2.1 Deleted

3.5.2.2 Table 3-1 identifies authorized coating materials for SE. All SE receiving a new paint finish will have a contrasting
color or black (color number 37038) block of no less than 2-1/2 inches, applied to the SE as close as practical to ID plate by
the activity that applied the paint. Stencils or decals may be used for the paint block. Figure 3-1 shows an example of a typical
paint block.

3.5.2.3 Air Force will accept chemical agent resistant coating painted SE procured through US Army when it would
increase the cost to change the coating to an epoxy/ polyurethane coating system (MIL-PRF-23377/MIL-PRF-85285). If
chemical agent resistant coating painted equipment needs to be painted, the units shall refinish and maintain equipment using
the appropriate coating system required for the assigned location/mission. This is to be accomplished only during the normal
maintenance cycle.

3.5.3 Authorized Colors for Liquid Oxygen, Nitrogen, Storage Carts and Tanks. All liquid oxygen, liquid nitrogen
servicing carts and storage tanks shall be finished in color schemes as follows:

3.5.3.1 Liquid oxygen servicing carts used on flight line shall have all of the control housing, interior and exterior, and cart
frame shall be painted SAE-AMS-STD-595, gray color number 26173.

3.5.3.2 Liquid nitrogen servicing carts used on flight line shall have all of the control-housing, interior and exterior painted
SAE-AMS-STD-595, gray color number 26173.

3.5.3.3 All 50 to 400 gallon liquid oxygen tanks shall be painted SAE-AMS-STD-595, green color number 14187, in
accordance with MIL-STD-101C, AFMAN 91-203 and the equipment-specific TO.

3.5.3.4 All 50 to 400 gallon liquid nitrogen tanks shall be painted SAE-AMS-STD-595, gray, number 16187, in accordance
with MIL-STD-101C, AFMAN 91-203 and the equipment-specific TO.

3.5.3.5 Only 2,000 gallon or larger liquid oxygen and nitrogen tanks not used on the flight line shall be painted SAE-AMS-
STD-595, white color number 17925.

3-6
 TO 35-1-3

TO-35-1-3-101CH10

Figure 3-1. Typical Marking for Paint Facility/Finish Identification Block

NOTE
For non-standard, unique coatins, or unknown MIL-Specs, add manufacture part number or product code.

3.5.4 Passenger or Loading Ramps. Passenger or loading ramps may be painted white, SAE-AMS-STD-595, number
17925. The steps and lettering shall be blue, SAE-AMS-STD-595, number 15045, except those surfaces covered with
anti-skid walkway coatings.

3.5.5 Presidential Support Equipment and USAF Demo Team. Presidential support equipment and the USAF Demo
Team are authorized to deviate from the color and coating requirements of this technical order.

3-7
 Table 3-1. Authorized Coating Systems

3-8
Coating Intermediate
TO 35-1-3

Process Substrate System Pretreatment Primer (Tie-coat) Topcoat Remarks Finish Process

NOTE

Comply with all cited coating requirements in Chapter 3, if a conflict exists, follow the manufacturer recommendation.

1 Abrasive Blast, Ferrous Alloys Two-Part New Procurement MIL-PRF- MIL-PRF- Use only spray 1. Depot and/or
White (Bare) other than Primer and TT-C-490 Type IV. 32550, Type I, 85285, Type equipment contractor, if using
Metal Stainless Steel, Topcoat For Depot and/or Form A, Class IV designed for the zinc-phosphate
(Paragraph Mill-galvanized, System contractor S the application pre-treatment
3.16.2) mill-electrozinc refurbishment of metal-rich apply TT-C-490
coating, or TT-C-490 Type IV primer. Type IV material.
mill-aluminized is suggested but MIL-DTL- 2. Prime to a Dry
surfaces not required 53022, Class Film Thickness
(Optional) L, Type IV (DFT) of 2.0-2.5
mils.
3. Topcoat to a DFT
of 1.6 to 2.4 mils.
2 Abrasive Blast Non-Ferrous (bare Corrosion Pretreat bare MIL-DTL- MIL-PRF- MIL-DTL- 1. Pretreat bare
(Bare Metal) aluminum alloys) Inhibiting aluminum areas 53022, Class 85285, Type 53022, Class aluminum areas
(Paragraph Primer and with MIL-DTL- L, Type IV IV L, Type IV is with MIL-DTL-
3.3.2.1.2) High Solids 5541, Class 1A III MIL-PRF- preferred for 5541, Class 1A or
Topcoat (Depot or 23377, Type I, maximum Anodize per
Contractor level Class N corrosion MIL-A-8625,
only) Anodize per protection of Type II or III
MIL-A-8625, bare alumi- (Depot or
Type II or per TO num. Contractor level
1-1-691. only) in accor-
dance with TO
1-1-691.
Tie-coats 2. Prime bare
cannot be used aluminum areas to
on bare metal a DFT of 0.6 to
substrates. 0.8 mils.
3. Topcoat to a DFT
of 1.6 to 2.4 mils.
 Table 3-1. Authorized Coating Systems - Continued

Coating Intermediate
Process Substrate System Pretreatment Primer (Tie-coat) Topcoat Remarks Finish Process
3 Abrasive Blast Non-Ferrous (bare Use Use MIL-PRF- Use MIL- Use Use pre- Apply MIL-PRF-
(Bare Metal) Aluminum alloys) MIL-PRF- 32239 PRF-32239 pre- treatment, 32239.
Paragraph 32239 treatment, primer, and top
3.16.2 primer, and coat in NOTE
Non- top coat in accordance
Chromated accordance with MIL- MIL-PRF-
Alternative, with PRF-32239 32239
use only with MIL-PRF- designed to
System 32239 encompass
Program Office pretreat,
approval. primer and
Paint Placard topcoat as a
must be system.
applied
showing
coating system
and will be
applied within
close proximity
to Data
Plate/Field#.
(Use TO 1-1-8
as an example)
Size as
required.

3-9
TO 35-1-3
 Table 3-1. Authorized Coating Systems - Continued

3-10
Coating Intermediate
TO 35-1-3

Process Substrate System Pretreatment Primer (Tie-coat) Topcoat Remarks Finish Process
4 Scuff-sand and Ferrous alloys and Standard Pretreat bare MIL-DTL- Tie-coat MIL-PRF- MIL-PRF- 1. Pretreat bare
Overcoat bare aluminum Primer and aluminum areas 53022, Class materials in 85285 Type 53022, Class aluminum areas
(Paragraph alloys High Solids with MIL-DTL- L, Type IV accordance IV L, Type IV is with MIL-DTL-
3.3.2.3) Topcoat 5541, Class 1A III with Para- preferred for 5541, Class 1A or
Process may be or PreKote SP per graph maximum Anodize per
used for TO 1-1-8 3.3.2.3.2 shall corrosion MIL-A-8625,
components be utilized on protection. Type II or III
and interior painted metal. (Depot or
items of an Contractor level
asset. only).
MIL-PRF-
23377, Type I, MIL-PRF- 2a. Prime bare
Class N 23377 Class aluminum areas to
N, is suitable a DFT of 0.6 to
for both bare 0.8 mils.
MIL-PRF- ferrous and 2b. Prime bare ferrous
32550, Type I, bare alumi- areas to a DFT of
Form A, Class num. 1.5 (±0.2) mils.
S
MIL-PRF- 2c. Intermediate
32550, Type I, prime over
Form A, Class existing coating
S shall only be system to a DFT
used on of 0.6 to 0.8 mils.
ferrous alloys.
Tie-coats 3. Topcoat to a DFT
cannot be used of 1.6 to 2.4 mils.
on bare metal
substrates.
 Table 3-1. Authorized Coating Systems - Continued

Coating Intermediate
Process Substrate System Pretreatment Primer (Tie-coat) Topcoat Remarks Finish Process
5 Units deployed Ferrous alloys and Chemical Tie-coat MIL-DTL- Three-part 1. Pretreat bare
with Army bare aluminum Agent materials in 64159 waterborne aluminum areas
(Paragraph alloys Resistant accordance coating system with MIL-DTL-
3.5.2.3) Coating with Para- requires 5541, Class 1A or
graph specialized Anodize per
3.3.2.3.2 shall application MIL-A-8625,
be utilized on equipment. If Type II or III
painted metal. unit is not to (Depot or
be deployed Contractor level
with the Army, only) per TO
use MIL-PRF- 1-1-691.
85285 topcoat.
Tie-coats 2a. Prime bare
cannot be used aluminum areas
on bare metal with MIL-PRF-
substrates. 23377, Type I,
Class N to a DFT
of 0.6 to 0.8 mils.
2b. Prime bare ferrous
areas with
MIL-DTL-53022,
Class L, Type IV
to a DFT of 1.5
(±0.2) mils.
2c. Intermediate
prime over
existing coating
system to a DFT
of 0.6 to 0.8 mils.
3. Topcoat to a DFT
of 2 (±0.2) mils.
6 Thermal Abrasive Blasted Metalization None None None MAJCOM Topcoating is Refer to Paragraph
Coating Ferrous alloys and Option not required. 3.16.4.
Systems bare aluminum
(Paragraph alloys
3.16.4)

3-11
TO 35-1-3
 Table 3-1. Authorized Coating Systems - Continued

3-12
Coating Intermediate
TO 35-1-3

Process Substrate System Pretreatment Primer (Tie-coat) Topcoat Remarks Finish Process
7 Walkways and Anti-skid None A-A-59166 MIL-PRF- Follow manufacturer’s
Stepping 17951, application instruc-
Surfaces Adhesive tions.
(Paragraph backed;
3.20) non-slip
material may
be used as an
alternate.
8 Undercoating Undercoat A-A-59295 Topcoating in Follow manufacturer’s
(Paragraph this area prior application
3.22) to undercoat- instructions.
ing is not
required.
 TO 35-1-3

Table 3-2. SE Scoring/Category Criteria

Category Deterioration/Corrosion Action Required

Category 1 New paint or recently touched-up. Unit requires no touch-up.
No chips, cracks, or scratches exposing bare metal Apply CPCs in corrosion prone interior and exterior
Coating not faded or mismatched. areas as preventive maintenance. No visible rust or
No visible rust or blistering of coating at seams. blistering of coating at seams. Refer to Paragraph 3.13.
Category 2 Minor corrosion or surface rust that can be Any of there conditions can be repaired by spot sanding
removed by sanding or wire brush. or wire brushing and touch-up on the spot aerosol spray,
Minor paint chipping, peeling or scratches. brush or roller. Refer to Paragraph 3.3.3 for touch-up
Minor paint fading or chalking. guidance.
Replacement of corroded fasteners, latches, An application of CPC can be applied as a temporary
fittings, and handles. repair until the unit can be scheduled for permanent
repair Refer to Paragraph 3.13.
Once the above repair actions are accomplished, the unit
can be placed in Category 1.
Category 3 Moderate corrosion or surface rust. Conditions can be repaired by removing panels and
Moderate paint chipping, peeling or scratches. routing through fabrication flight for repair and
Moderate paint fading or chalking. repainting or by sending whole unit for a partial or
complete scuff and overcoat. Refer to Paragraph 3.3.2.3
Moderate to localized extensive corrosion on for scuff sand and overcoat instruction.
removable panels or parts.
There is excessive paint chipping, peeling or An application of CPC can be applied as a temporary
scratches. repair until the unit can be scheduled for permanent
There is excessive amount of paint missing. repair. Refer to Paragraph 3.13.
Spot-welded panel seams leaching rust.
Overall look is excessively faded or weathered. Once the above repair actions are accomplished, the unit
will be placed in the appropriate category.
Category 4 75 percent of the total exterior surface displays Conditions necessitating extensive disassembly of the
obvious oxidation, bleaching, peeling, cracking, unit prior to complete stripping by media blasting to
flaking, etc. remove corrosion.
Severe corrosion or surface rust and pitting. Unit will be de-painted and repainted in accordance
Extensive paint chipping or peeling covering whole with the standard paint system in Table 3-1.
sections.
Rusting through leaving holes through panels, An application of CPC can be applied as a temporary
seams, framework, chassis or axles. repair until the unit can be scheduled for permanent
Units requiring extensive local manufacturing of repair. Refer to Paragraph 3.13.
new panels, framework or chassis components. Once the above repair actions are accomplished, the unit
will be placed in the appropriate category.

3.6 CORROSION TREATMENT FOR STEEL CABLES.

If the surface of a cable is corroded, relieve cable tension and carefully force the cable open by reverse twisting. Visually
inspect the interior. Corrosion on the interior strands constitutes failure and the cable must be replaced. If no internal
corrosion is detected, remove loose external rust and corrosion with a clean, dry, coarse-weave rag or fiber brush. Clean the
control cables with a clean dampened cloth with MIL-PRF-680, Type II or III, CID A-A-59601, or MIL-PRF-32295, Type II.
After thorough cleaning, apply a thin film of either MIL-L-87177, Type I or II, Grade B, or MIL-PRF-16173, Class II, Grade
3 water displacing CPC to the cable surface by aerosol spray or a cloth dampened with the CPC followed by a liberal
application of MIL-PRF-16173, Class II, Grade 4 CPC with a non-metallic brush. Wipe off any excess CPC. If excessive CPC
is allowed to build up, it will interfere with the operation of cables at fairleads, pulleys, or grooved bell-crank areas.

3.7 PIANO TYPE HINGES.

Water displacing, corrosion inhibiting CPC are often applied to hinge pins and nodes to provide lubrication and to reduce
corrosion problems unless otherwise directed by a specific system workcard, immediately after SE washing conclude, apply a
coating of MIL-PRF-63460 or MIL-L-87177, Type I or II, Grade B to the piano hinge, hinge pins and nodes.

3-13
TO 35-1-3

3.8 MATING SURFACES PROTECTION REQUIREMENTS.

To prevent corrosion between mating surfaces (faying or back to back surfaces of a part) on attaching parts, fasteners and
panels, the metal surfaces shall be insulated with the proper primer following Paragraph 3.8.1 and Paragraph 3.8.1.1 or with
sealant following the information in paragraphs and subparagraphs of Paragraph 3.8.2.

3.8.1 Mating Surfaces-Bare Steel. For clean bare steel alloys, except stainless steel, the primer shall be MIL-PRF-32550,
Type I, Form A, Class S, or MIL-DTL-53022, Class L, Type IV. If the surface or part is already primed and the primer is
intact, further coating of the mating surface is not required.

3.8.1.1 Mating Surfaces-All Other Metals. For nonferrous metals, the primer shall be MIL-DTL-53022, Class L, Type IV,
or MIL-PRF-23377, Type I, Class N.

3.8.2 Sealers and Sealant Usage. Sealants prevent the intrusion of moisture, rain, salt water, dust and other fluids which
can lead to extensive corrosion. Sealants are one of the most important tools for corrosion prevention and control.

3.8.2.1 Many sections of the SE contain joints and flanges. The use of an appropriate sealer to prevent the entry of water
and contaminants into crevices and joints is an excellent way to minimize corrosion. Sealers can also be used to separate two
conductive metal surfaces preventing galvanic or crevice corrosion.

3.8.2.2 For sealants to be effective, it is critical that the correct sealant be chosen for a specific area/situation and that it be
applied correctly. TO 1-1-691 dedicates the entire Chapter 6 to the advanced selection and applications of sealants. Refer to
that chapter if sealing conditions or requirements are encountered that are beyond the scope of this manual.

3.8.2.3 When repairs are made on equipment or accessories and/or components are installed or structures are reinstalled,
the attaching or faying surfaces shall be protected by sealing all metal-to-metal and composite to metal contact surfaces. All
permanent structures shall be installed with faying surfaces wet with MIL-PRF-81733, Type I or IV, Class 1 or 2, Grade A
sealant. All removable structure such as access doors, inspection plates, floor panels and plates, and other removable panels
(components requiring frequent removal for maintenance requirements) shall either be installed with faying surfaces wet with
AMS 3367, Class A or B or PR-1773, Class B sealant or Av-DECTM HT3935-7 or HT3,000FR sealant tape in the joints as
specified by the system specific maintenance manual. In addition to faying surface sealing, fillet seal all interior seams and all
exterior seams (those exposed to the outside environment) that would allow water intrusion using MIL-PRF-81733, Type II,
Class 1 or 2, Grade A sealant.

NOTE

The following does not apply to parts that are lubricated in the joint areas immediately before or after installation,
or to close tolerance bolts and parts that are removed frequently for maintenance requirements.

3.8.2.3.1 Attaching parts, such as nuts (standard, speed, and self-locking), bushings, spacers, washers, screws (standard and
self-tapping), sleeves for shake-proof fastener studs, clamps, bolts, etc., do not need to be painted in detail except when
dissimilar metal or wood contact is involved with the materials being joined or exposure to a corrosive interior environment or
the exterior environment will occur in service. However, all parts shall be installed wet with sealant. For permanent installa-
tions, use MIL-PRF-81733, Type I or IV, Class 1 or 2, Grade A sealant and coat the entire mating surface of the parts. For
removable installations, use SAE AMS 3367, Class A or PR-1773, Class B sealant and coat only the lower side of the heads of
screws and bolts with sealant. For removable installations, do not coat the threads and shanks of screws and bolts or the holes
into which they are inserted because this will make future removal almost impossible without damaging the parts. As an
alternate for removable installations, the shanks, threads, and lower side of the heads of standard screws and bolts may be
coated with MIL-PRF-63460, MIL-PRF-16173, Class II, Grade 3 before they are installed. Close tolerance bolts and parts
shall be coated with corrosion inhibiting, solid film lubricant. Use MIL-L-23398 or MIL-PRF-46147 (air curing type) on
aluminum parts and on all types of metallic parts. The solid film lubricant shall be applied and completely cured prior to
assembly. Bolts shall be coated on shanks and threads only. A thin bead of sealant shall be applied under the bolt head to
impart a wet seal.

3.8.2.3.2 All rivets shall be installed wet with MIL-PRF-81733, Type I or IV, Class 1 or 2, Grade A sealant. In fuel contact
areas, the exposed rivet head and approximately 1/4-inch of the adjacent structure shall be brush over coated with SAE
AMS-S-8802 Class A sealant.

3-14
 TO 35-1-3

3.8.2.3.3 All machine screws, countersunk fasteners, bolts (head end) and nuts which are used in contact with magnesium
shall be installed with 5056 aluminum alloy washers. These parts, including the washers, shall be installed wet with MIL-
PRF-81733, Type II, Class 1, Grade A sealant and shall be completely fillet sealed with the same material after installation.

3.8.2.3.4 Adjustable parts, such as tie rod ends and turnbuckles shall be installed as follows: (1) If possible, surfaces and
threads shall be lubricated and protected before assembly with a film of MIL-L-23398 or MIL-PRF-46147 (air curing type)
corrosion inhibiting, solid film lubricant which shall be completely cured prior to assembly. After installation, apply a thin
coating of MIL-PRF-63460; MIL-PRF-16173, Class II, Grade 3; or MIL-PRF-81309, Type II, water displacing, CPC, to all
surfaces of these parts. (2) If solid film lubricants cannot be applied, use a thin coating of MIL-PRF-63460; MIL-PRF-16173,
Class II, Grade 3; or MIL-PRF-81309, Type II water displacing, CPC after assembly.

3.8.2.3.5 When practical, slip fit parts shall be assembled with mating surfaces wet with MIL-PRF-81733, Type I or IV,
Class 1 or 2, Grade A sealant. If this process is not practical, coat the (ID) of the holes in the receiving part, which is normally
the larger structure with a corrosion inhibiting, solid film lubricant conforming to MIL-L-23398 or MIL-PRF-46147 (air
curing types) and the outer diameter of the mating part with one conforming to MIL-L-23398 or MIL-PRF-46147 (air curing
types). The solid film lubricant shall be applied and completely cured prior to assembly.

3.8.2.3.6 All cut edges and holes drilled or reworked for bolts, screws, rivets, studs, and bushings of aluminum alloy
structures or parts shall receive a chemical conversion coating treatment prior to the installation of the fasteners or bushings
and prior to installing or refinishing the structure or parts. Apply a conversion coating to aluminum surfaces, using Touch-N-
Prep pen containing AlodineTM 1132. On steel surfaces use the appropriate primer to coat the cut edges of holes prior to
reinstallation of the parts.

3.8.2.4 Sealant may be applied by brush, spatula, or caulking gun application.

3.8.2.5 To prevent sealant from contacting adjacent areas during application and smoothout, outline the areas being sealed
with masking tape (AMS-T-21595, Type I) so that each tape strip is 1/8 to 1/4 inch from the edge of the seams.

3.8.2.5.1 Apply the sealant between tapes with a nonmetallic spatula or spreader, brush or caulking gun. Avoid the
entrapment of air. Work sealant into recesses by sliding the edge of the spatula firmly back over the recesses. Smoothing will
be easier if the nonmetallic spatula is first dipped in water.

3.8.2.5.2 Remove masking tape after the sealant has been applied and before it begins to set. Cure time will depend upon
the application life of the materials used.

3.8.2.6 Sealant application life and cure times are dependent on environmental considerations and the formulation cure
times. The application life of a sealant is the length of time that a mixed sealing compound remains usable at 75 °F (24 °C)
and 50 percent relative humidity. This time (in hours), known as a dash number, is denoted as the last number in a sealant
designation (e.g. MIL-PRF-81733, Type II, has an application life of two hours). For each 18 °F (10 °C) increase in the
temperature above 75 degrees Fahrenheit (°F) (24 degrees Celsius (°C), the application time is cut by approximately half with
a similar reduction in tack free and cure time. When sealants are applied in an environment where the relative humidity is
greater than 50 percent, its application life is shortened to some degree. Maintenance personnel should be aware of the effects
of temperature and humidity on the application life of a sealant. Mix only the amount of material that can be applied during
the rated work life of the sealant.

3.8.2.7 There are sealants that can damage SE. For example Room Temperature Vulcanizing (RTV) Adhesive/Sealant,
MIL-A-46106, unless it is called-out for a specific repair, should not be used in sealing metal parts. This sealant evolves acetic
acid during its curing process and can cause corrosion when sealing metals or when sealing non-metals in a confined metallic
lined space. The approved qualified product for use is MIL-A-46146 (non-corrosive). Both sealants are packaged alike and are
often substituted within the base supply system. A telltale odor of vinegar identifies the acetic acid (corrosive version)
evolving is being used.

3.8.2.8 Remove sealant with a non-metallic scraper, such as plastic or phenolic. The Pneumatic Vibro Gun Sealant Removal
Kit or rapid desealing system may also be used (Refer to Table A-1). Clean remaining residue from the component or
structure using undiluted Acrastrip 600 or SkyKleen® 1,000.

3.9 ACOUSTICAL MATERIAL PRECAUTIONS.

Most of the acoustical material used in powered SE is open cell polyurethane foam. The property of open cell polyurethane
that results in the reduction of sound also results in the foam holding water and water vapor like a sponge. In severe corrosion

3-15
TO 35-1-3

prone areas, the foam also absorbs the contaminates in the water vapor such as salt. The water vapor is slow to dry and will be
sufficient to cause and accelerate corrosion. Additionally, as the water vapor evaporates it will leave the contaminates lodged
in the foam against the metal surfaces and over time the concentration of the contaminates will worsen the corrosive effects.
To prevent corrosion that will occur from the open cell polyurethane, field units are authorized to remove existing foam and
replace with coustifoam polyurethane insulation or acoustic foam (heat reflective) or equivalent.

3.9.1 Coustifoam Polyurethane Insulation and Acoustic Foam. The coustifoam polyurethane insulation and acoustic
foam is also an open cell polyurethane foam but the side that has the vapor/waterproof backing shall be installed against the
metal panels. This action will help prevent fluid transfer to the metal surfaces of the equipment where the foam is mounted.
All exposed edges, tears, and perforations of the foam will be sealed prior to installation. Sealing can be accomplished by
brushing the edge with MIL-PRF-81733 or equivalent sealant. The sealant shall also be used to repair any tear or puncture in
the polyvinylfluoride film that are made to accommodate fastener installation.

3.9.2 Nonmetallic Fasteners. Nonmetallic fasteners shall be used to mount the foam in the SE. Corrosion inhibiting
sealant, MIL-PRF-81733 or PR-1733 shall be applied around the fastener head and the fastener shank, which protrudes
through the equipment structure/skin, thoroughly sealing the fastener hole to prevent water intrusion. Do not apply sealant to
threaded portions of the fasteners.

3.10 DRAINAGE.

3.10.1 Fluid Collection Points. Angles, channels, panel lips, hand rail holders, or other pockets that can collect water will
be avoided or have adequate drainage when stored in the equipment’s normal position, (see Figure 3-1.1).

3.10.2 Modifying Fluid Collection Points. Sealants such as MIL-PRF-81733 or self leveling sealing compounds such as
Zip Chem HT3326-5-50 or TF2219 or equivalent may be used to fill voids and entrapped areas, redirecting the water to the
appropriate drain-through-drain-to location. The minimum size for any drain hole is 0.25 inch.

TO-35-1-3-015

Figure 3-1.1. Example of Standing Water Due to Inadequate Drainage Provisions

3-16
 TO 35-1-3

3.11 MAINTENANCE STAND RAILS AND RAIL HOLDERS.

3.11.1 Drain Holes.

Do not drill drain holes in weldments seams or beads. Failure to comply could result in injury to, or death of,
personnel or long term health hazards.

NOTE
Using activities that find standing or entrapped water in equipment due to the lack of drainage should forward this
information to the responsible equipment specialist or system engineer for action through Material Deficiency
Reporting channels as outlined in TO 00-35D-54.

Field units are authorized to drill necessary drain holes at the lowest point on the maintenance stands rail holders to avoid
water from collecting in the holders.

3.11.2 Drain Hole Corrosion Prevention and Treatment. Paint the edges of the drain holes after drilling to prevent
corrosion from occurring around the holes.

3.11.2.1 Since repeated installation and removal of the rail into the rail holder will result in damage to the paint on both
items, additional protection is required on the ID of the holder and the outside diameter of the bottom part of the rail.

3.11.2.2 Coat the ID of the rail holder and the bottom part of the stand rail that are inserted into the holder with solid film
lubricant conforming to MIL-L-23398 or MIL-PRF-46147 (air curing types). The solid film lubricant shall be applied and
completely cured prior to assembly.

3.11.2.3 To prevent corrosion, CPC, MIL-PRF-16173, Grade 4, or MIL-PRF-81309, Type II should be applied periodically
to the exterior bottom of the rail and interior of the holder and the interior of the stand rails. Use the appropriate length 360
degree FORMIT® spray wand or equivalent to apply CPC through the drain holes the entire length of the stand rails.

DRAINS (TYPICAL) DRAIN

TO-35-1-3-016

Figure 3-2. Hollow Member Drain Hole Configuration

WELD-NUT

TO-35-1-3-017

Figure 3-3. Hollow Member Weld-Nut Configuration

3-17
TO 35-1-3

3.12 HOLLOW STRUCTURAL MEMBERS.

3.12.1 Drainage for Closed Hollow Members, When Open Drain Holes are Possible. A completely air tight weld is
required for closed hollow members to prevent condensation of moisture in the interior surface. To prevent moisture accumu-
lation from occurring (since it is difficult to obtain perfect welds), all closed hollow members will have drainage provisions at
the lowest drain-through-drain-to point of the member, reference Figure 3-2.

3.12.1.1 For horizontal members, drain hole(s) will be provided on the lower side equally spaced across the hollow member
at an approximately thirty-six inch interval.

3.12.1.2 For vertical members, drain hole(s) will be provided on bottom end-cap.

3.12.2 Drainage for Closed Hollow Members, When Open Drain Holes are Not Possible. If a drain hole is not
possible due to design (such as a butt joint with a plate behind it or two pipes forming a saddle joint) then a drain hole should
be placed at the lowest possible drain-through-drain-to point, (see Figure 3-3). Application of sealant that is formed to direct
the drainage to the drain hole is authorized to facilitate fluid drainage.

3.12.2.1 The drain hole should not penetrate a weld and must be approved by the responsible engineering organization.
Since the location of the drain hole could allow water inside the hollow member insert a removable plug (weld-nut) into the
drain hole. Preferred size of the hole for the weld-nut is 0.50 inch, minimum size is 0.375 inch Length will be as determined
by the hollow member wall thickness. A suggested source of supply for the weld nuts is available from the Molly Division of
USM Corp., 504 Mt. Laurel Avenue, Temple, PA 19560 or any Chevrolet Truck Parts Department.

3.12.2.2 Weld nuts should be removed periodically so the hollow member can be checked for water accumulation and
condition of the corrosion prevention compound. If water has to be drained, completely dry the area and reapply the appropri-
ate CPC the entire length of the hollow member. After a period of two to three years the rubber may compress in the hole, if
this occurs remove the screw, cut the weld-nut flush with the surface, punch the remainder of the nut inside the hollow
member and install a new weld-nut.

3.13 CORROSION PREVENTIVE COMPOUNDS.

CPC are used for temporary protection of painted and unpainted surfaces and where coating system has been damaged or
removed. CPC’s function by preventing corrosive materials from contacting and corroding bare metal surfaces. The selection
for the type of CPC to be used shall take into consideration CPC appearance to help maintain overall condition of the SE for
scoring purposes and help reduce the need for increased complete repaints. Dark color CPC should not be used in highly
visible areas. Transparent or lightly tinted CPCs are the best selection for temporary corrosion prevention and control on
visible areas. Some of the compounds have the capability of displacing moisture in seams, joints and faying surfaces. Some
CPC’s also provide lubrication as well as corrosion protection. The thicker CPC’s provide the best corrosion protection, are
longer lasting, and more difficult to remove. The thinner materials provide some lubrication and do not crack; chip or peel but
must be removed and replaced. The protection provided is temporary, so the compound must be reapplied periodically and
after removal by washing or contact with solvents or fuel. The recommended maximum frequency of application is based on
the corrosion severity of the operational environment. The frequency of application can be set to coincide with wash cycles
and periodic inspections, but should not be extended. These compounds should not be considered as a long-term alternative
for proper painting. The CPCs should not be applied at temperatures above 95 °F or below 50 °F. A brief description of
authorized CPC’s are listed below.

3-18
 TO 35-1-3

3.13.1 MIL-PRF-81309.

CPC shall not be used on or adjacent to oxygen lines, fittings or equipment. The compound shall not be used on
surfaces where temperatures exceed 300 °F. Failure to comply could result in injury to, or death of, personnel or
long term health hazards.

CPC can be separated into two major categories: water displacing and non-water displacing compounds (refer to
TO 1-1-691). Some CPC’s have a flash point above 100 °F, but contain flammable solvents. These compounds
should be handled, stored, and applied in accordance with manufacturer’s instructions and the product Safety Data
Sheet (SDS). Failure to comply could result in damage to, or destruction of, equipment or loss of mission effective-
ness.

MIL-PRF-81309 (CPC Water Displacing Ultra Thin Film) is a general-purpose corrosion preventive compound that can be
used whenever a CPC or a water-displacing compound is called for but no specification is referenced. MIL-PRF-81309
materials are excellent water displacing compounds that provide an ultra thin, soft protective film (0.5 millimeter (mil) or
less). The specification covers two types, both of which can be applied by dipping, spraying, brushing, or an aerosol container.
They provide temporary protection from corrosion and are easily removable with a solvent. The two types primarily in used
for SE are Types II and III.

• Type II. A soft, thin film for general use, particularly on moving or sliding parts where some lubrication is needed,
such as hinges or bomb racks. It may be washed away by rain or wash procedures. Type II shall be used to protect
areas which cannot be properly drained or contain recesses that are particularly difficult to reach.

• Type III. An ultra thin, soft film primarily for use on avionics and electronic equipment. Although this coating is
nonconductive, it will allow electrical contact because it is soft and very thin. Do not use MIL-PRF-16173, Grade 3
as a substitute.

3.13.2 MIL-DTL-85054. MIL-DTL-85054 CPC is a water displacing CPC that forms a clear, dry, flexible film. It is
intended for use as a protective coating until painting is practical. Because of its paint-like characteristics, this CPC does not
provide any lubrication. It can be applied by dipping, brushing, spraying, or from aerosol containers. However, dipping
provides a very thin coating with less corrosion protection. After each use of an aerosol can, invert the can and spray until
spray tip (nozzle) is clear of entrapped material. If an aerosol can does not spray, invert and depress the spray tip several times
to clear the delivery tube and spray head. If the can still does not spray, remove and clean the plastic spray head then spray
again to clear the delivery tube. Since MIL-DTL-85054 buildup is difficult to remove, especially after prolonged exposure to
direct sunlight, previously applied coatings should be removed with MIL-PRF-680, Type II or III (CID A-A-59601) or
MIL-PRF-32295, Type II.

3.13.3 MIL-PRF-16173 CPC Solvent Cutback, Cold Application. MIL-PRF-16173, Class 2, covers five different
grades of CPCs that can be applied by brushing or dipping. Grades 1, 2, 4, and 5 do not displace water and must be applied to
dried surfaces or to surfaces that have been treated with MIL-PRF-81309. Grade 3 is a water displacing soft film, but is not a
substitute for MIL-PRF-81309. All five grades are very effective in preventing corrosion. As a soft film CPC, care must be
taken to ensure dirt and other contaminants do not collect on the soft CPC surface for extended periods of time.

• Grade 1. A thick hard, black CPC that is difficult to remove. However, it offers the most corrosion protection of all
the CPCs indoors and outdoors and may be used at temperatures down to 0 °F. Should not be used in highly visible
areas. Use either Grade 4 or MIL-DTL-85054 semitransparent CPC.

• Grade 2. A thick, soft, grease-like, brown CPC that remains tacky and can be removed with mineral spirits or dry
cleaning solvent. It protects under relatively severe conditions and, given adequate maintenance touch-up as
necessary, can be used for most maximum protection requirement. It may be used at temperatures down to -40 °F.

• Grade 3. A thin, soft film CPC. MIL-PRF-81309, Type III can be used as a substitute for MIL-PRF-16173; however,
MIL-PRF-16173 cannot be used as a substitute for MIL-PRF-81309.

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• Grade 4. A thin, non-tacky, semitransparent film through which identification can be read. It may be used at tempera-
tures down to -40 °F.

• Grade 5. A soft film CPC removable using low pressure steam.

3.13.4 MIL-PRF-63460 Lubricant, Cleaner, and Preservative for Weapons and Weapon Systems. MIL-PRF-63640
is a thin, water displacing, protective, penetrating lubricant used for cleaning, lubrication and preservation of components.
This material has good lubricating properties between -65° and 105 °F (-54° and 41 °C). It may be applied by brushing,
dipping, or spraying.

3.13.5 MIL-L-87177 Lubricants, Water Displacing. MIL-L-87177 covers several types and grades of a synthetic, water
displacing lubricant that has shown excellent corrosion preventive qualities, especially on electrical contacts, contact pins,
electrical quick disconnect connectors, etc. There are two types and grades. Type I, Grade B is a water displacing lubricant
with an added corrosion inhibitor. Grade B is the preferred material for use on SE electrical contacts and connectors.

3.13.6 CPC Methods of Application. CPCs can be applied by brushing, dipping, or spraying. The area of application,
viscosity of the CPC and the conditions under which the CPC need to be applied are factors which determine which methods
of application to use. Use of the FORMIT® extension wand applicator, or equivalent, may be used to fog the thinner version
of CPCs inside drain holes or other access areas.

3.14 CPC APPLICATION ON FERROUS ALLOYS.

Clean the surface where CPC is to be applied by removing loose/lifting materials with a steel/stainless wirebrush or scotch-
brite pad. Wipe the area clean prior to applying CPC. Apply by brush, dip, or spray. For hard to reach recesses, field organiza-
tions, utilizing spray wands, aerosol extension applicator such as the FORMIT® extension applicators, or equivalent devices,
to fog or spray the CPC MIL-PRF-16173, Grade 4 or Zip Chem, ZC-010 (MIL-PRF-81309 Type 2), onto the interior surfaces
of the hollow members. Fully insert the FORMIT® 360 degree extension wands, or equivalent applicators, into the drain hole
and slowly withdraw the spray wand while applying the CPC to the interior of the hollow member. Repeat this process for
each drain hole ensuring complete coverage between drain holes. Depot overhaul or contractor maintenance shall condition
the interior of the hollow members with an iron phosphate pretreatment per TT-C-490, Type II, then apply the CPC as above.

3.15 CPC APPLICATION ON OTHER ALLOYS.

Clean the surface where CPC is to be applied by removing loose/lifting materials with a stainless wirebrush or scotch-brite
pad. Wipe the area clean prior to applying CPC. Field organizations shall utilize spray wands, FORMIT® 360 degree
extension wands, or equivalent devices, to fog or spray the CPC MIL-PRF-16173, Grade 4 or (MIL-PRF-81309 Type II), onto
the interior surfaces of the hollow members ensuring complete interior coverage. Depot overhaul or contractor maintenance
shall condition the interior of aluminum hollow members per TO 1-1-691 with a chromate conversion coating per MIL-DTL-
5541, Class 1A or anodize per MIL-A-8625, Type II or III. The specific treatment shall depend on the alloy. Apply the
appropriate CPC, as above, after the pretreatment operations.

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Table 3-3. Pretreatment Instructions

Material Finish Process

A. FERROUS ALLOYS other than 1. Chemically clean the areas in accordance with Chapter 3. Remove all
stainless steel, mill-galvanized or remaining coating and corrosion by abrasive blasting or other mechanical
mill-electrozinc coating, or cleaning processes. Field organizations without abrasive blasting capabilities
mill-aluminized surfaces. may proceed to Step 3. Depot and/or contractor level of maintenance apply
zinc phosphate TT-C-490, Type I.
2. The blasted surfaces will be in a near-white condition per Steel Structures
Painting Council (SSPC-SP 10). A near-white blast cleaned surface finish is
defined as one from which all oil, grease, dirt, mill scale, rust, corrosion
products, oxides, paint or other foreign matter have been completely removed
from the surface except for very light shadows, very slight streaks, or slight
discolorations caused by rust stain, mill scale oxides, or slight, tight residues
of paint or coating that may remain. At least 95 percent of each square inch of
surface area shall be free of all visible residues, and the remainder shall be
limited to the light discoloration mentioned above. The national association of
corrosion engineers standard TM-01-70 (Visual Standard for Surfaces of New
Steel Airblast Cleaned with Sand Abrasive) surface was produced as a visual
standard to compare properly prepared surfaces. The Standard may be
procured from national association of corrosion engineers standard Interna-
tional, 440 South Creek Drive, Houston, TX 77084-4906. The blast-cleaned
surface must be primed before any rusting occurs, otherwise the benefit of the
near-white blast cleaning is lost. Under normal atmospheric conditions it is
best practice to prime within one hour of blast cleaning.
The following areas are exceptions to blasting:
• Abrasive blasting will not be performed on surfaces where there is a
danger of warping or distorting the base metal. Sheet metal thinner than
0.0625 inch (U.S. Standard 16 gauge) will not be abrasive blasted.
3. Primer-The preferred coating system over abrasive blasted ferrous alloys are
MIL-PRF-32550, Type I, Form A, Class S, or MIL-DTL–53022, Class L, Type
IV. Follow the coating manufacturer’s instructions for the mixing, application,
time between coats, and the required application equipment. The dry film
thickness shall be thickness of the MIL-PRF-32550 shall be 2.5 to 3.5 mils.
The dry film thickness of MIL-DTL-53022, shall be 1.5 (±0.2) mils. If the
surface is not reconditioned to bare metal, the use of a non-chromate tie-coat
is required. Apply MIL-DTL-53022, Class L, Type IV, or MIL-PRF-23377,
Type I, Class N, shall be applied over painted areas as a tie-coat.
4. Topcoat-Paint with one coat of MIL-PRF-85285, Type IV applied to a dry film
thickness of 1.6 to 2.4 mils.
B. STAINLESS STEEL AND 1. Most stainless steel surfaces do not require finishing. If there are requirements
NICKEL BASE ALLOYS. in the equipment specific technical order to coat stainless steel, and the
technical order provided the coating procedures those instructions shall take
precedence. If no instructions are available and coatings are required use the
following application processes.
2. Clean in accordance with Chapter 2, if the surface remains contaminated refer
to TO 1-1-691.
3. Passivate the surface in accordance with SAE-AMS-QQ-P-35 (Depot or
Contractor levels of maintenance only).
4. Primer-MIL-DTL-53022, Type IV (Lead and Chromate Free, Epoxy Primer).
Allow the primer to dry. Dry film thickness shall be 1.5 (±0.2) mils.
5. Finish-Paint with one coat of MIL-PRF-85285, Type IV applied to a dry film
thickness of 1.6 to 2.4 mils. Total dry film thickness of all coatings shall be 2.9
to 4.1 mils.
C. MAGNESIUM ALLOYS 1. Clean in accordance with Chapter 2, if the surface remains contaminated refer
to TO 1-1-691.
2. Pretreat with dichromate film per SAE-AMS-M-3171, Type III.

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Table 3-3. Pretreatment Instructions - Continued

Material Finish Process

3. Primer-Prime with one coat of epoxy primer, MIL-DTL-53022, Class L, Type
IV, or MIL-PRF-23377, Type I, Class N. Dry film thickness for MIL-DTL-
53022 shall be 1.5 (±0.2) mils. Dry film thickness for MIL-DTL-23377 shall
be 0.6 to 0.8 mils.
4. Finish-Finish with one coat of MIL-PRF-85285, Type IV applied to a dry film
thickness of 1.6 to 2.4 mils. Total dry film thickness of all coatings shall be 2.9
to 4.1 mils (53022) or 2.2 to 3.2 mils (23377).
D. CADMIUM OR ZINC PLATED 1. Clean in accordance with Chapter 2.
SURFACES, mill-galvanized, 2. Pretreat by applying MIL-C-17711 (Depot and/or contractors only).
millelectro-zinc coated. 3. Primer-Prime with one coat of epoxy primer, MIL-DTL-53022, Class L, Type
IV, or MIL-PRF-23377, Type I, Class N. Dry film thickness for MIL-DTL-
53022, shall be 1.5 (±0.2) mils. Dry film thickness for MIL-PRF-23377 shall
be 0.6 to 0.8 mils.
4. Finish-Finish with one coat of MIL-PRF-85285, Type IV applied to a dry film
thickness of 1.6 to 2.4 mils. Total dry film thickness of all coatings shall be 2.9
to 4.1 mils (53022) or 2.2 to 3.2 mils (23377).
E. MILL-ALUMINUM STOCK. 1. Clean in accordance with Chapter 2.
2. Pretreat with MIL-DTL-5541, Class 1A or Anodize per MIL-A-8625 Type II
or III (Depot or contractors only) per TO 1-1-691.
3. Primer-Prime with one coat of epoxy primer, MIL-DTL-53022, Class L, Type
IV, or MIL-PRF-23377, Type I, Class N. Dry film thickness for MIL-DTL-
53022 shall be 1.5 (±0.2) mils. Dry film thickness for MIL-PRF-23377 shall
be 0.6 to 0.8 mils.
4. Finish-Finish with one coat of MIL-PRF-85285, Type IV applied to a dry film
thickness of 1.6 to 2.4 mils. Total dry film thickness of all coatings shall be 2.9
to 4.1 mils (53022) or 2.2 to 3.2 mils (23377).

3.16 COATING APPLICATIONS.

3.16.1 Material Selection. To provide optimum protection from deterioration and corrosion, the proper coating system (a
combination of cleaning, pretreatment, priming and topcoat) must be selected for a specific application. See Table 3-1 for
authorized coating systems. Table 3-3 is a brief abstract of the priming and painting functions necessary to maintain the
coating systems on SE.

3.16.2 SE Surface Preparation Categories. SE surface preparation for painting operations fall into four general
categories:

• Paint removal (removal of old coating system).

• Cleaning.

• Corrosion removal and prepaint treatment.

• Prime and topcoat.

3.16.3 MIL-PRF-85285 Polyurethane, Type IV. The standard topcoat used on SE is MIL-PRF-85285, Type IV. The
selection of polyurethane paint, MIL-PRF-85285, Type IV by field, depot, and contractor operations, is restricted to only those
vendors who have been qualified to the performance specification. Those vendors are listed on Qualified Products Database,
QPD-85285. To download the latest version of current specifications, handbooks, or Qualified Products List/Database
(QPL/QPD) use the Defense Logistics Agency Specification search engine (https://quicksearch.dla.mil/qsSearch.aspx).

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3.16.4 Thermal Spray Coating Systems.

NOTE

When polyurethane is applied below 40 percent relative humidity and/or 60 °F, the cure time is appreciably
lengthened. The coating application range for MIL-PRF-85285 is relative humidity 20 to 80 percent and ambient
temperature 50 to 90 °F.

There are several methods of thermally spraying metal alloys. For coating large pieces of SE, the most commonly used
equipment in the Air Force is dual metal wire electric arc spray. The equipment recommended should be for high, field and
depot level production levels. Organizations may use the Thermion 500 and the Thermion Bridgemaster or equivalent systems
for metalizing operations. Thermion equipment may be procured from Thermion Metalizing System, Ltd., P.O. Box 2136,
Silverdale, WA 98383-2136. Table 3-4 lists currently authorized metalization materials and preferred sources of supply.

3.16.4.1 Metalization Process Metal Wire Arc Spray (MWAS). MWAS is a thermally sprayed, sacrificial metalized coating
for effective protection of structural iron and steel in corrosive environments. For ferrous metal surfaces, other than stainless/
corrosion resistant steel, 85/15 percent zinc/aluminum alloy wire has shown the widest application and corrosion protection
latitude. 85/15 percent zinc alloy, 1/8-inch diameter is the common wire diameter. Organizations may use this alloy for all
application on properly prepared ferrous metals over 1/8-inch thick, except stainless/corrosion resistant steel alloys. For
aluminum equipment or ferrous metal used in a high temperature zones use METCO Aluminum wire or equivalent, 99.0
percent purity, 1/8 inch diameter.

3.16.4.1.1 In the MWAS process, two electrically isolated wires of the selected coating material are given opposite DC
polarity using an arc-welder power supply. The wires are simultaneously fed to an application gun where they are brought into
close proximity to initiate an electric arc. The arc between the two impinging wires results in a local region of high tempera-
ture plasma and molten metal. A jet of compressed air, directed through the arc region from behind, disperses and projects the
molten metal to the surface being coated. The metal droplets impinge on the substrate; solidify and bond to form a continuous
barrier/sacrificial metal coating for cathodic protection of the metal structure. The application gun remains 8-12 inch from the
metal surface and negligible heat is imparted to the substrate even during extended coating activities.

NOTE

The air supply must be sufficiently free of oil and moisture so that no visible oil or moisture appears on the blasted
surface.

3.16.4.1.2 All surfaces to be thermal sprayed shall be abrasive blasted to a minimum of a near-white metal blasted surface
and roughened to a minimum of a 2 mil surface profile. If paint, oil or bituminous materials are present they must be removed
prior to the final blast operation. If the surface is chemically contaminated, it may be necessary to wash it or neutralize it
before final blasting.

The MWAS process produces high localized noise levels and ultraviolet radiation emissions from the arc region.
Prior to commencing initial MWAS operations consult with the Base Bioenvironmental Engineer (BBE) for
approval. Proper hearing, eye protection, and respiratory Personal Protective Equipment (PPE) will be designated
by the local BBE. Failure to comply could result in injury to, or death of, personnel or long term health hazards.

3.16.4.1.3 The abrasive media used for cleaning heavily contaminated surfaces should not be reused for the final blast,
even though it is rescreened as the media may contain contaminates that will be re-embedded in the metal surface causing
corrosion and/or coating adhesion failure.

3.16.4.1.4 Follow the thermal spray equipment manufacturers’ preparation and application instructions. The metal coating
shall be applied to a minimum thickness of 6 mils and maximum of 8 mils.

3.16.4.1.5 Any surface, which shows visible moisture, rust, scale or other contamination shall be re-blasted before
spraying. The surface must be completely coated to the specified thickness within six hours of abrasive blasting.

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The correct thickness of thermal spray coating in this application is critical. A coating that is too thin will not
provide corrosion protection while a coating that is too thick will chip and flake off. Failure to comply could result
in damage to, or destruction of, equipment or loss of mission effectiveness.

3.16.4.1.6 The metalized coating shall be inspected for thickness by using the multi-metal dry film thickness gage to
ensure correct surface thickness is achieved. Any thin or uncoated areas must be immediately roughened with a mechanical
grinder with a minimum of a 25 grit disc to apply a cross-hatch pattern to the substrate. Immediately apply the thermal spray
coating to reach the proper coating thickness.

3.16.4.1.7 On high temperature components metalized with aluminum, organization may use METCOSEAL SA silicone
aluminum sealer to prevent any rust staining that may occur. This sealer is available from:

METCO INC.
1101 Prospect Avenue
Westbury, L.I., N.Y. 11590

Table 3-4. Metalization Material Sources of Supply

Material Use Source of Supply

85/15 percent zinc/aluminum Best overall general purpose corrosion The Platt Brothers & Company
alloy protection on abrasive blasted carbon steel P.O. Box 1030
surfaces. Waterbury, CT 06271
AUFHAUSER Corporation
39 West Mall
Plainview, NY 11803
100 percent aluminum For coating hot sections of equipment, Alcotec Wire Corporation
mufflers, and aluminum equipment. 2760 Aero Park Dr.
Traverse City, MI 49686
AUFHAUSER Corporation
39 West Mall
Plainview, NY 11803
90/10 percent aluminum/ For the application of a tough durable, Alcotec Wire Corporation
aluminum oxide alloy long-term anti-slip coating to steel and
aluminum surfaces. 2760 Aero Park Dr.
Traverse City, MI 49686
AUFHAUSER Corporation
39 West Mall
Plainview, NY 11803
100 percent zinc Excellent corrosion protection except in The Platt Brothers & Company
seawater immersion conditions P.O. Box 1030
Waterbury, CT 06271
AUFHAUSER Corporation
39 West Mall
Plainview, NY 11803

3.17 FIELD LEVEL MAINTENANCE PAINTING REQUIREMENTS.

Field level maintenance-painting requirements for SE with polyurethane are divided into two types, touch-up painting and
general maintenance painting.

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3.17.1 Touch-Up Painting. Touch-up painting is defined as minor touch-up and/or sectionalized painting of equipment
using authorized coating to prevent corrosion. When spot painting, the amount of paint used should be enough to cover the
affected area plus a one inch overlap to seal the area’s edges. Treat scratched areas that are one half inch wide by three inches
long or less, or chips one inch in diameter or less will be touched-up with CPC (temporary repair), or approved primers and
topcoats preloaded in items such as but not limited to: SEMPENS, Preval compressed air spray packs, Clip-Pacs, Brush and
Roller, or Akzo Nobel Two-Component MIL-PRF-85285 Aerosol Can. Single component aerosols, enamels or lacquers are
not authorized coatings. Information about these materials can be viewed on the AFCPCO website located on the AF Portal.
Larger scratches/chips in paint or damaged areas will be grounds to repaint the complete section per Paragraph 3.3.

3.18 MAINTENANCE PAINTING.

3.18.1 Maintenance Painting Restrictions. Although it is not recommended, it is a common field level practice during
maintenance painting to repeatedly overcoat the entire exterior surface. Under no circumstance should the total number of
layers of paint ever exceed six (6). The number of layers can be determined during the featheredge sanding of damaged areas.
Count each layer of primer as one and each layer of topcoat as one, the total of which should never exceed six.

3.18.1.1 Equipment exceeding this maximum number of paint layers should be scheduled for complete coating removal
and repainting.

Excessive numbers of paint layers will result in hidden corrosion going unnoticed or interlaminar failure of the
coatings at one of the coating boundaries. Failure to comply could result in damage to, or destruction of, equipment
or loss of mission effectiveness.

3.18.1.2 Powder coated equipment shall be touched up using MIL-PRF-85285, Type I or II. SEMPEN or the prepackaged
spray touch-up kits shall be used on small areas less than one square foot. All damaged areas shall be feather-edge sanded
along the edge damaged area to allow the repair coating to blend in the surrounding areas. The remaining areas to be
touched-up shall be scuff sanded with 180 or 240 grit abrasive paper. All bare aluminum areas resulting from coating failure
shall be pretreated with the chromate conversion coating SEMPEN prior to priming. The bare areas shall be primed and
topcoated with one of the authorized organic coating systems listed in Table 3-1.

3.18.2 Prepackaged Coating Touch-Up Kits. For minor primer and paint touch-up such as scratches and other small
repair, the use of prepackaged touch-up kits manufactured with the compatible the authorized conversion coatings, primers
and topcoats are encouraged.

3.18.2.1 Use of the prepackaged touch-up kits minimizes material waste and personnel exposure to paints and solvents
while allowing for the use of the proper coating system for the repair.

3.18.2.2 SEMPENs, Preval compressed air spray packs, Clip-Pacs, or Akzo Nobel Two-Component MIL-PRF-85285
Aerosol Can are currently obtainable in MIL-PRF-85285, Type I, high solids polyurethane. Single component aerosols,
enamels or lacquers are not authorized coatings. Information about these materials can be viewed on the AFCPCO website
located on the AF Portal.

3.18.3 Radiators Coatings. Radiator coatings are preapplied at the OEM. Field repair is limited to touch-up of the body
and attach points of the radiator but not the radiator vanes/core. For touch-up, use the appropriate color of polyurethane from
Appendix A. A thin layer of water displacing, hard film CPC, MIL-DTL-85054, may be fogged into the radiator vanes for
added protection or for temporary repair. Do not use soft film CPC materials as the coating may collect dirt and debris on the
cooling vanes reducing the efficiency of the radiator. An aerosol extension kit such as the FORMIT® 90 degree applicator, or
equivalent, may be used to fog the CPC into recessed areas of the radiator. Heavy buildup of the paint and/or CPC is to be
avoided. To prevent CPC buildup, remove and reapply the CPC, MIL-DTL-85054 during normal wash cycles. Use of soft film
CPC is not recommended as they tend to collect contaminates and would reduce the cooling efficiency of the radiator.

3.19 LIQUID OXYGEN AND LIQUID NITROGEN SERVICING CARTS AND STORAGE TANKS.

Liquid nitrogen and liquid oxygen servicing carts and storage tanks will be drained and purged in accordance with the
applicable equipment technical order prior to cleaning and painting.

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3.19.1 Authorized Materials for Liquid Oxygen and Nitrogen Tanks.

All valves and instrumentation shall be masked after draining and purging to prevent contamination and explosion
hazard during cleaning and painting. Failure to comply could result in damage to, or destruction of, equipment or
loss of mission effectiveness.

The colors for liquid oxygen, liquid nitrogen servicing carts and storage tanks will be according to Paragraph 3.5.3. Liquid
oxygen and nitrogen servicing carts and storage tanks will be primed with one coat of epoxy primer, MIL-DTL-53022, Class
L, Type IV, or MIL-PRF-23377, Type I, Class N primer and one coat of MIL-PRF-85285, Type IV topcoat. Dry film thickness
for MIL-DTL-53022 shall be 1.5 (±0.2) mils, MIL-PRF-23377 shall be 0.6 to 0.8 mils, and MIL-PRF-85285 shall be 1.6 to
2.4 mils. Exceptions to this finish system shall be approved by the end item engineering authority.

3.20 WALKWAYS AND STEPPING SURFACE COATINGS.

The stepping, standing and/or walking surfaces of stands, metal ladders, platforms, tops of deicing-decontamination unit
tanks, etc., shall be coated with walkway coating, A-A-59166. Expanded metal, grating and other anti-skid plates are
exempted as long as they are safe from slippage. Adhesive backed, non-slip material MIL-PRF-17951 may be used as an
alternate. Follow the non-slip material manufacturers’ application instructions.

3.21 COLORS FOR WASTE CONTAINERS.

Containers (Bowsers) used for holding explosive or highly flammable materials will be painted and marked in accordance
with TO 42B-1-23.

3.22 SE UNDERCOATING.

A-A-59295 undercoating is authorized for use by field units. The undercoating is intended for use in one thick coat (1/8 inch)
on the underside of fenders, floors, etc., to deaden noise, to act as a seal against fumes and to protect the metal from corro-
sion.

3.22.1 SE Undercoating Considerations. The undercoat may be applied to a primed surface. Topcoating in this area
prior to undercoating is not required. Ensure the undercarriage of the equipment is clean prior to application of the undercoat-
ing. Do not apply over corrosion.

NOTE

For maximum corrosion protection, undercoating should be applied by the original equipment manufacturer during
production.

3.22.1.1 The undercoat is not fluid resistant and fuels/fluids/ solvents will readily cause deterioration of the coating.
Undercoat should not be used in an area subjected to fluid spills.

3.22.1.2 The undercoat should never be applied over a component (such as a transmission) where the coating would result
in the undesired retention of heat.

3.22.1.3 Undercoating is not resistant to temperatures in excess of 325 °F and should not be used in such areas.

3.23 STORAGE COMPARTMENTS.

Storage compartments for ducts or hoses, which use a pad, or matting for abrasion resistance are highly susceptible to
corrosion because of the water absorbing characteristics of those materials. Field activities should remove the pads/matting
and replace the mat with an abrasion resistant floor covering by using one of the following techniques after removal of all
corrosion and the surface is completely prepared for the selected coating.

a. Apply MIL-PRF-81733 sealant 1/8 inch thick over a clean primed and painted surface.

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b. Apply Scotch Brand Abrasion-Resistant Polyurethane Film (8561) over a clean primed and painted surface. The film is
available in four inch wide rolls and can be easily trimmed to fit any contour or shape. The surface must be clean to
permit the adhesive backing to bond properly.

c. Apply 85/15 percent zinc/aluminum metallization 4-6 mils thick on bare, abrasive blasted steel surfaces.

d. Apply a sprayable polyurethane truck bed liner type coatings, Morton Paint Company, PN 1440-2, or equivalent on high
wear areas and storage compartment interiors. Colors shall be black or consistent with the existing color utilized on the
equipment. The coating shall be applied over the existing primer and polyurethane topcoat paint system.

3.24 SPLIT WHEEL ASSEMBLIES.

3.24.1 Split Wheel Coating Requirements. To prevent corrosion on the mounting flanges of the split wheels accomplish
the following:

a. Remove all corrosion and clean the flanges.

b. For carbon steel wheels mechanically clean the split wheel assemblies and apply metal-rich primer, MIL-PRF-32550,
Type I, Form A, Class S to a dry filming thickness of 2.5 to 3.5 mils. Allow primer to completely dry in accordance with
manufacturer’s instructions prior to assembly.

c. MIL-DTL-53022, Class L, Type IV, applied to a DFT of 1.5 (±0.2) mils, is an acceptable alternate for metal-rich paint
on split wheel assemblies. Allow primer to completely dry in accordance with manufacturer’s instructions prior to
assembly.

d. If primer is used, apply a thin film of uncatalyzed, low adhesion sealant PR-1773 to the mating surfaces of the split
wheels after the primer has cured to prevent fluid intrusion and assist in future wheel disassembly.

e. Reassemble per applicable technical order and apply a bead of sealant RTV MIL-A-46146 around the inflation valve
stem to prevent water entry. Tires will be treated with a commercial tire dressing, and all valve stem caps will be plastic.

3.25 MUFFLERS.

To reduce corrosion problems on muffler components a thermal sprayed aluminum coating may be used. The effectiveness of
the coating is dependent upon the particular component and the environment (temperature, time at temperature, and time to
reach temperature). The effectiveness will also be dependent upon the condition of the component prior to thermal spraying,
the coating will be more effective on a new component than on a reconditioned component that had already rusted.

Figure 3-4. Corrosion Under Data Plate

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3.26 MISCELLANEOUS CLEANING, SEALING, AND CPC REQUIREMENTS.

3.26.1 Sealing of Addressograph or Dash-A Plates.

NOTE
Do not apply thermal spray pure zinc, 85/15 percent zinc/ aluminum or pure aluminum to stainless steel muffler
components.

Whenever an Addressograph or Dash-A-Plate is used in lieu of die cut vinyl markings or stencils as data plates, they should
be installed wet with corrosion inhibiting sealant, MIL-PRF-81733. The requirement for wet installation also includes the
fasteners used for installation. Using the sealant will prevent corrosion from occurring between the data plate and SE.

3.26.2 Electrical Hardware and Terminals.

NOTE

Clean corrosion on terminal studs with a wire brush or terminal stud-cleaning tool.

3.26.2.1 For cables and terminal posts, brush on a light coat of petrolatum, VV-P-236 Grease.

3.26.2.2 For battery frame and holder, apply one coat of primer, MIL-DTL-53022, Class L, Type IV, or MIL-PRF-23377,
Type I, Class N primer, and one coat of MIL-PRF-85285, Type IV topcoat. Dry film thickness for MIL-DTL-53022 shall be
1.5 (±0.2) mils, MIL-PRF-23377 shall be 0.6 to 0.8 mils, and MIL-PRF-85285 shall be 1.6 to 2.4 mils.

3.26.3 Light Assemblies. Instructions for cleaning the light assemblies are as follows:

a. Remove corrosion with abrasive mat, A-A-58054 and MIL-PRF-680, Type II or III, CID A-A-59601 or MIL PRF-
32295, Type II, wipe off residue and allow to air dry.

Solvent will cause softening and deterioration of rubber gaskets, seals, and insulation. Failure to comply could
result in damage to, or destruction of, equipment or loss of mission effectiveness.

b. Clean electrical contacts with MIL-PRF-29608, Type I, Electrical Contact Cleaner.

c. Apply a thin layer of CPC, MIL-L-87177, Grade B, to the contacts.

3.26.4 Internal Electrical Components: Circuit Breakers, Relays, etc. Instructions for removing and cleaning internal
electrical components are as follows:

Do not remove thin plating on electrical components. Always use the mildest method of corrosion removal. Failure
to comply could result in damage to, or destruction of, equipment or loss of mission effectiveness.

a. Remove heavy corrosion by rubbing contact surfaces with an abrasive typewriter eraser. Remove light to medium
corrosion by rubbing contact surface with ruby red eraser.

b. Clean contacts with MIL-PRF-29608, Electrical Contact Cleaner, Type 1, Class C. Clean relay or circuit breaker
assembly with acid brush, A-A-289. Remove foreign matter with a soft brush.

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 TO 35-1-3

• Do not apply CPC MIL-C-81309 to printed circuit boards. Contact points must be clean for CPC to function
properly. Failure to comply could result in damage to, or destruction of, equipment or loss of mission effective-
ness.

• Care must be taken to avoid removing thin plating. Failure to comply could result in damage to, or destruction
of, equipment or loss of mission effectiveness.

c. Apply a thin coat of CPC MIL-L-87177, Grade B, to relays and contacts.

3.26.5 Electrical Connectors.

Replace all connectors that show moderate to severe corrosion damage. Failure to comply could result in damage
to, or destruction of, equipment or loss of mission effectiveness.

Remove light corrosion with toothbrush, A-A-59 or A-A-123, soaked in solvent, TT-I-735, isopropyl alcohol.

3.26.5.1 Apply CPC MIL-L-87177, Grade B, to internal surfaces. Preserve outer shell with MIL-PRF-16173, Grade 4.
Wipe off excess with a clean cloth.

3.26.5.2 For equipment operating, deploying to, or based in, severe corrosion prone locations, the use of Av-DEC HiTAK
polyurethane stretch seal is authorized for use around mated electrical connectors, coaxial connectors, and electrical quick
disconnect fittings.

3.26.6 Switches. Cleaning instructions for the switches are as follows:

a. Scrub switch with isopropyl alcohol, TT-I-735 and toothbrush, A-A-59 or A-A-123. Wipe with clean cloth, CCC-C-46.
Allow to air dry.

b. Apply a thin coat of CPC MIL-L-87177, Grade B to the electrical contact points.

c. Wipe all sliding contacts, cams, and contact points with a clean cloth, CCC-C-46, Class 4 or pipe cleaner to remove
CPC.

3.26.7 Wire Harness and Cables. Instructions for cleaning the wire harness and cables are as follows:

NOTE

• Contact points must be clean of CPC to function properly.

• Cleaning solvents and compounds may adversely react with plastics such as harness tubing, gaskets, seals, etc.
Test a small area for softening or reaction prior to general use.

3.26.7.1 Scrub corroded area with MIL-PRF-29608. Flush area with cleaning compound. Shake excess solvent from wire
harness. Remove residue with a clean cloth, CCC-C-46 and allow to air dry.

3.26.8 Heli-Coil Insert Replacement. Steps for removal of the insert are as follows:

a. Remove the defective insert.

b. Clean and dry the female thread from which the defective insert was removed.

c. Apply MIL-PRF-23377, Type I, Class N primer sparingly to the cleaned female thread.

d. Before the primer dries, install new insert and remove the insert driving tag.

3-29/(3-30 blank)
 TO 35-1-3

CHAPTER 4
MARKING OF SUPPORT EQUIPMENT
4.1 SE MARKINGS CROSS-REFERENCE.

Support equipment marking requirements have been removed from this technical order. Reference Technical Order (TO)
35-1-18, Marking of USAF General Support Equipment (SE), for all SE markings.

4-1/(4-2 blank)
 TO 35-1-3

CHAPTER 5
CORROSION PREVENTION AND CONTROL OF HUSH HOUSES
5.1 MATERIALS.

There are three basic materials used in the construction of Hush Houses. The primary material being galvanized steel, the
galvanizing will offer improved corrosion protection over the plain carbon steel. The second material used is carbon steel,
which is susceptible to a corrosion environment. The third material used are Types 321 and 409 stainless steel that may be
specified in numerous rework contracts for use in the hot section. Types 321 and 409 stainless steel is weldable and will offer
adequate corrosion protection.

5.1.1 Fastener Replacement. Any fastener replacement should be accomplished using either stainless steel fasteners or
hot dip galvanized fasteners.

5.2 REPAIR.

To prevent dissimilar metal related problems, do not use zinc plated or hot dipped zinc fasteners on stainless or
corrosion resistant steel parts. Failure to comply could result in damage to, or destruction of, equipment or loss of
mission effectiveness.

5.2.1 Galvanized Steel. The amount of corrosion present will determine what is required for repair. If the corrosion is
minor, then either abrasively grind the corrosion or chemically treat with pretreatment compound. If the corrosion is severe or
widespread, abrasive blasting may be required.

5.2.1.1 If an entire galvanized steel component is replaced, then every side of that component must be primed prior to
installation. If any part of the installation process, such as welding, damages the paint, the exposed damaged area will be
cleaned and repainted with thinned organic zinc-rich primer.

5.2.1.2 Hush House galvanized sheet should be hot dip galvanized per ASTM A446 Grade C, coating G-210.

5.2.2 Carbon Steel. All accessible carbon steel items require sandblasting prior to application of the respective zinc-rich
paints. The sandblasting and subsequent painting of an assembled structure will provide protection to the exposed portion of
the structure. If there is corrosion in a seam or joint, refer to Paragraph 5.2.2.2.

5.2.2.1 If an entire component (panel, plate, beam, support) is replaced. Then every side of that component must be primed
prior to installation. If any part of the installation process, such as welding, damages the paint, the exposed damage area will
be cleaned and repainted with thinned inorganic zinc-rich primer.

Failure to prime faying (back to back) surfaces of carbon steel will result in corrosion that cannot be treated without
extensive repair or disassembly.

5.2.2.2 Carbon Steel (Angle Iron) seams, such as a T-angle, having corrosion, will require the following procedure to
remove and treat corrosion.

a. Apply phosphoric acid corrosion removing compound. Allow the material to dwell on the surface for 30-45 minutes-add
additional material to keep the surface wet. Agitate with thin bristled steel brush, if necessary, to remove heavier rust.

b. Rinse area and check for rust; metal conditioner if necessary.

c. Allow area to dry.

5-1
TO 35-1-3

d. Mask gaps at lower sides of angle iron T’s with masking tape per SAE-AMS-T-23397 or equivalent.

NOTE

• Use of sealant gun is recommended for injecting sealant into entire gap.
• Above procedure should only be accomplished for treating existing corrosion problems in this area.

e. Fill entire gap using sealant MIL-PRF-81733, Type IV.

SPOT
WELD
GAP

STRUCTURAL STEEL (ANGLE IRON) T GAPS/SEAMS

TO-35-1-3-125

Figure 5-1. Angle Iron Sealant Application

5.2.3 Stainless Steel. Characteristics of stainless steel are as follows.

5.2.3.1 Type 321 Stainless Steel. Type 321 stainless steel has good corrosion resistance to oxidation and corrosion.
Because of a small amount of titanium, Type 321 stainless steel does not harden during welding and therefore, does not
require a post weld relief. Normally, the steel has a shiny surface with areas of dull gray streaks. The streaking is caused by
the titanium content and is not harmful.

5.2.3.2 Type 321 has the following weld properties:

• Gas Metal-Arc. When welding Type 321 to itself, use Type ER321 wire electrode.

• Shielded Metal-Arc (covered electrodes). Use ER321 wire electrode.

• Gas Tungsten-Arc. This procedure should be used when welding Type 321 to mild steel. Filler metals should be
ER308L.

5.2.3.3 Do not coat Type 321 stainless steel with any of the zinc-rich paints. The zinc in the paints can embrittle the
stainless steel under certain conditions. The use of Type 321 that is in contact with zinc-rich painted carbon steel (as in the hot
section) is acceptable.

5.2.3.4 American Iron and Steel Institute (AISI) 409 Stainless Steel. AISI 409 Stainless Steel is the lowest cost of all
stainless steels yet it has good resistance to oxidation and corrosion. Because of a small amount of Titanium, the AISI 409
does not harden during welding and; therefore, does not require a post weld relief. Normally the steel has a shiny surface with
areas of dull gray streaks. The streaking is caused by the titanium content and is not harmful.

5.2.3.5 The AISI 409 has the following weld properties:

• Gas Metal-Arc. The electrode wire should be Type 309 stainless steel when welding AISI 409 to mild steel. When
welding AISI 409 to itself, use Type W 414 T filler.

• Shielded Metal-Arc (covered electrodes). Use W 17-4 PH, 12 Cr-4 MO or Type 330-04 electrodes.

5-2
 TO 35-1-3

• Gas Tungsten-Arc. When fillers are required, use Type 410 with 0.08 percent Max C or W 414 Ti. Helium shielding
is preferred over argon shielding.

5.2.3.6 Do not coat the AISI 409 with any of the zinc-rich paints. The zinc in the paints can embrittle the stainless steel
under certain conditions. The use of AISI 409 that is in contact with zinc-rich painted carbon steel (as in the hot section) is
acceptable.

5.2.3.7 Sealing. Mating surfaces where moisture could enter from the top or horizontal will be sealed with sealant
MIL-PRF-81733 (cold section) and sealant SAE-AMS-3374, Type I (hot section) after primer application and before topcoat
application.

5.3 PRETREATMENT COMPOUNDS.

5.3.1 Rust Remover 81287 (Naval Jelly).

Rust remover Permatex 81287 contains phosphoric and sulfuric acid. Use with adequate ventilation. Consult with
the local bioenvironmental engineer for approved personal protective equipment. In event of skin or eye contact,
flush immediately with plenty of water. Failure to comply could result in injury to, or death of, personnel or long
term health hazards.

Rust remover Permatex 81287 is a biodegradable rust remover and pretreatment compound for galvanized steel.

5.3.1.1 Follow the manufacturer’s application instructions for corrosion removal. Repeat the process until all corrosion is
removed. Allow to air dry prior to the application of a protective coating.

5.3.1.2 Rust remover Permatex 81287 is available from:

Permatex
Rocky Hill CT, 06067
(860) 571-5100

5.4 PRIMERS.

5.4.1 Organic Metal-Rich Primer. The primer shall be MIL-DTL-53022, Class L, Type IV. No alternate coatings are
authorized.

5.4.1.1 Dry film thickness of applied primer shall be of 1.5 (±0.2) mils.

5.4.1.2 This primer requires top coating when used on exterior surfaces (refer to Table 5-1).

5.4.2 Inorganic Zinc-Rich Primers. MIL-PRF-23236, Type I, Class 3 is an inorganic zinc/rich primer that is usually
furnished as two or three components.

5.4.2.1 Follow the manufacturer’s instructions for mixing, thinning, and application.

5.4.2.2 Only those products listed on QPD-23236 are authorized.

5.4.2.3 During application of the MIL-PRF-23236 primer, the product should be constantly agitated to prevent the zinc dust
from settling.

5-3
TO 35-1-3

Table 5-1. Hush House Coating Chart

Area Material Primer Topcoat

Hot Section Carbon Steel 100 percent Aluminum Metallization Process Metal Wire Arc Spray MIL-PRF-85285,
(Exterior) (MWAS), or MIL-PRF-23236, Type VI, Class 13 Type IV
Door Structure Carbon Steel 85/15 percent Zinc/Aluminum MWAS, or Organic Metal-Rich Primer MIL-PRF-85285,
MIL-DTL-53022, Class L, Type IV Type IV
Cold Section Galvanized Permatex 81287 and Organic Metal-Rich Primer MIL-DTL-53022, MIL-PRF-85285,
Steel Class L, Type IV, or 85/15 percent Zinc/Aluminum MWAS Type IV

5.5 PAINTING.

5.5.1 Structural Corrosion Protection.

NOTE
Prior to total repaint of Hush House, accomplish corrosion repair procedures in accordance with Paragraph 5.2.

Corrosion protection for the Hush House consists of MIL-PRF-23236 inorganic zinc primed steel (door frame beams, support
beams, exhaust tube) and ASTM A446, Grade G210 galvanized panels (roof, walls, door). This corrosion protection system
should be adequate in all but extremely severe corrosion environments.

5.5.2 Camouflage Requirements. The selection of colors for an exterior camouflage pattern should be restricted to those
readily available for MIL-PRF-85285. MAJCOM will determine the need and color requirements for the operating locations
requesting the application of a camouflage pattern to the Hush House.

5.6 INORGANIC ZINC PRIMED SURFACES.

NOTE

• To prevent streaking and other problems, it is necessary to work from the bottom to the top and not allow
previously worked surfaces to dry.
• The amount of surface area to be worked at any time should not exceed the surface area that can be epoxy
primed and polyurethane topcoated in one day.

5.6.1 Primer Requirements on the Door Frame Beams, Support Beams, and Exhaust Tube. Primer requirements
are as follows:

NOTE
Examine the primed surface prior to cleaning. If the surface appears to be dirty (not oily), then MIL-PRF-87937,
Type IV soap should be sufficient to clean the surface. If the surface is oily, it will be necessary to use one of the
soaps (MIL-C-43616 or MIL-PRF-87937, Type I), which contain solvent. In either case, it is absolutely necessary
that the surface be scrubbed while the soap is being applied. A clean water break free surface is necessary prior to
additional treatment.

a. Preferably on the day prior to painting, the surface to be coated the next day is to be cleaned. Use aircraft cleaning soap,
MIL-PRF-87937, or MIL-C-43616, as appropriate. Always clean from the bottom to the top to prevent streaking and
have one person applying rinse water to previously cleaned surfaces to also prevent streaking.

b. Early on the second day, apply one coat of MIL-DTL-53022, Class L, Type IV, or MIL-PRF-23377, Type I, Class N
primer, and one coat of MIL-PRF-85285, Type IV topcoat. Dry film thickness for MIL-DTL-53022 shall be 1.5 (±0.2)
mils, MIL-PRF-23377 shall be 0.6 to 0.8 mils.

c. Apply two coats of MIL-PRF-85285, Type IV to a total dry film thickness of 1.6 to 2.4 mils.

5-4
 TO 35-1-3

d. After the first topcoat has been allowed to dry a maximum of 4-6 hours, apply the desired camouflage pattern. If using
polyurethane, lightly scuff sand the area to be overcoated, then solvent wipe with Acetone, O-A-51, ASTM D329, prior
to painting.

5.7 GALVANIZED SURFACES.

NOTE
• To prevent streaking and other problems, it is necessary to work from the bottom to the top and not allow
previously worked surfaces to dry.

• The amount of surface area to be worked at any time should not exceed the surface area that can be zinc
conversion coated epoxy primed and polyurethane topcoated in one day.

5.7.1 Roof. Drape a barrier of paint drop cloths, barrier paper or other suitable material on the walls directly below area of
roof to be worked. The drape should be such to prevent fluids from contacting the wall.

NOTE

Examine the galvanized surface prior to cleaning. If the surface appears to be dirty (not oily), then MIL-PRF-
87937, Type IV soap should be sufficient to clean the surface. If the surface is oily, it will be necessary to use one
of the soaps (MIL-C-43616, Type II or MIL-PRF-87937, Type I), which contain solvent. In either case, it is
absolutely necessary that the surface be scrubbed while then soap is being applied. A clean water break free surface
is necessary prior to additional treatment.

5.7.1.1 On the day prior to painting, the surface to be coated the next day is to be cleaned. Use aircraft cleaning soap
MIL-PRF-87937 as appropriate. Always clean from the bottom to the top to prevent streaking and have one person applying
rinse water to previously clean surfaces to also prevent streaking.

5.7.1.2 Early on the second day, apply the pretreatment compound. Again work from bottom to top applying the compound.
Keep lower surfaces (even where the pretreatment compound was previously applied) flooded with water to prevent streaking.

5.7.1.3 As soon as the pretreatment compound has dried, apply one coat of organic zinc-rich primer to a dry film thickness
of 2.0 to 3.0 mils.

5.7.1.4 Apply one heavy coat of polyurethane MIL-PRF-85285, Type IV to a dry film thickness of 1.6 to 2.4 mils.

5.7.1.5 After the entire roof has been topcoated and allowed to dry a maximum of 4-6 hours, apply the desired camouflage
pattern. If using polyurethane, lightly scuff sand the area to be overcoated, then wipe with a scotch-brite pad, A-A-58054,
Type I, Grade A, dampened with MIL-PRF-87937 diluted per manufacturer’s instructions. After wiping with cleaner, rinse
surface with clean cloth dampened with water and dry with clean cloth prior to painting.

5.7.2 Walls and Doors. The walls should be worked only after the roof painting is complete. Work on the door can be
accomplished as desired. The air intake space in the wall formed by the screen wire and acoustical panels must be protected
during repainting operations to prevent entry of chemicals and paints. Cut pieces of plywood (or other barrier type materials)
and push the plywood against the screen wire from the interior side. Because of the difficulty in cleaning and painting the
solid wall area formed by acoustical panels and screen wire, it is recommended that a galvanized panel equal in width and
length be fabricated and attached to the solid wall areas by means of locally fabricated standoffs.

5-5/(5-6 blank)
 TO 35-1-3

CHAPTER 6
CORROSION PREVENTION AND CONTROL OF NOISE SUPPRESSOR
SYSTEMS (NSS)
6.1 GENERAL.

NSS are divided into the Cold Section (temperatures of less than 300 degrees Fahrenheit (°F)) and the Hot Section (tempera-
tures of 300 °F or more). Table 5-1 will identify the coating for a particular section based on the material and temperature.
Earlier NSS were coated with alkyd enamels (TT-E-489, TT-E-527) and high temperature aluminum paint (TT-P-28) both of
which are ineffective for corrosion prevention.

6.2 MATERIALS.

There are three basic materials used in the construction of NSS. The primary material being carbon steel this is extremely
susceptible to the corrosive environment generated by the suppressor. The second material used is galvanized steel and the
galvanizing will offer improved corrosion protection over the plain carbon steel, but can be used only in the Cold Section due
to temperature limitations of the galvanizing. The third material used is American Iron and Steel Institute (AISI) 409 stainless
steel and the material has been specified in numerous rework contracts for use in the Hot Section. AISI 409 is the least
expensive of all stainless steel, is weldable and will offer adequate corrosion protection.

6.3 FASTENER REPLACEMENT.

Any fastener replacement should be accomplished using either stainless steel fasteners or hot dip galvanized fasteners per
ASTM A394, A325, or A153 (as applicable).

6.4 STRUCTURAL REPAIR.

6.4.1 Structural Repair Carbon Steel.

Failure to prime faying (back to back) surfaces of carbon steel will result in corrosion that cannot be treated without
disassembly.

All carbon steel items require sandblasting prior to application of the respective zinc-rich paints. The sandblasting and
subsequent painting of an assembled structure will provide protection to the exposed portion of the structure, but if there is
corrosion in a seam or joint, then disassembly would be required.

6.4.1.1 If an entire component (panel, plate, beam, support) is replaced, then every side of that component must be primed
prior to installation. If any part of the installation process, such as welding, damages the paint, the exposed damaged area will
be cleaned and repainted after installation.

6.4.2 Galvanized Steel. The amount of corrosion present will determine what is required for repair. If the corrosion is
minor, then grind the corrosion and recoat with the pretreatment MIL-P-15238, and epoxy primer, MIL-DTL-53022, Class L,
Type IV, or MIL-PRF-23377, Type I, Class N. If the corrosion is severe or widespread, abrasive blasting may be required.
MIL-PRF-32550, Type I, Form A, Class S, organic metal-rich primer shall be used if ferrous/galvanized substrates that have
been blasted to bare metal.

6.4.2.1 If an entire galvanized steel component is replaced, then every side of that component must be primed prior to
installation. If any part of the installation process, such as welding, damages the paint, the exposed damaged area will be
cleaned and repainted after installation.

6.4.2.2 Any replacement galvanized sheet should be hot dip galvanized per ASTM A525, coating G-210. All structural steel
in the galvanized condition should be hot dip galvanized per ASTM A123.

6-1
TO 35-1-3

6.4.3 AISI 409 Stainless Steel. Characteristics of AISI 409 Steel are as follows:

6.4.3.1 AISI 409 Stainless Steel is the lowest cost of all stainless steels yet it has good resistance to oxidation and corro-
sion. Because of a small amount of titanium, the AISI 409 does not harden during welding and; therefore, does not require a
post weld relief. Normally the steel has a shiny surface with areas of dull gray streaks. The streaking is caused by the titanium
content and is not harmful.

6.4.3.2 The AISI 409 has the following weld properties:

• Gas Metal-Arc. The electrode wire should be Type AISI 409 to mild steel. When welding AISI 409 to itself, use Type
309 stainless steel when welding W 414 T filler.

• Shielded Metal-Arc (covered electrodes). Use W 17-4 PH, 12 Cr-4 MO or Type 330-04 electrodes.

• Gas Tungsten-Arc. When fillers are required, use Type 410 with 0.08 percent Max C or W 414 Ti. Helium shielding
is preferred over argon shielding.

6.4.3.3 Do not coat the AISI 409 with any of the zinc-rich paints. The zinc in the paints can embrittle the stainless under
certain conditions. The use of AISI 409 that is in contact with zinc-rich painted carbon steel (as in the Hot Section) is
acceptable.

6.5 SEALING.

Mating surfaces where moisture could enter from the top or horizontal will be sealed with sealant MIL-PRF-81733 (cold
section) or sealant SAE-AMS-3374, Type I (hot section) after primer application and before topcoat application.

6.6 PRIMERS.

6.6.1 Organic Zinc-Rich Primers.

Respirator with organic vapor cartridges is required for all painting/priming operations unless Bioenvironmental
Engineer has approved the work place for no respirator protection. Failure to comply could result in injury to, or
death of, personnel or long term health hazards.

The primer will be one of the previously described primers as identified in Chapter 3.

a. Dry film thickness should be 3.0 mils and approximately 5.0 mils wet.

b. Prior to repainting the exhaust area (or initiating a contract for repaint) it is important to know the surface temperature
of the exterior walls of the exhaust section. Approximate temperatures can be obtained with the use of Wahl Temp-Plate,
Wahl Instruments, Inc., Culver City, California, (800) 421-2853, or equivalent. If the temperature is below 300 °F this
area shall be coated with Cold Section finishes.

6.6.2 MIL-PRF-23236, Type I, Class 3. MIL-PRF-23236, Type I, Class 3 is an inorganic zinc-rich primer that is usually
furnished as two or three components.

6.6.2.1 Follow the manufacturers’ instructions for mixing, thinning, and application.

6.6.2.2 Only those products listed on QPD-23236 are authorized.

6.6.2.3 During application of MIL-PRF-23236 primer, the product should be constantly agitated to prevent the zinc dust
from settling.

6.6.3 Heat Resistant Primer Briner 2905. Instructions for applying Briner 2905 are as follows:

6-2
 TO 35-1-3

NOTE
Briner 4765 or Briner 2905 shall be used as a primer for Briner 2986.

a. Briner 2905 is two component, silver, heat resistant silicone coating. The zinc powder must be mixed into the SE before
using.

b. Thinning should not be necessary, but the coating can be thinned with Briner 70 Silicone Reducer to facilitate spray
painting.

c. Apply Briner 2905 by conventional spray. De Vilbiss MBC-510 Gun, 704 Air cap with E needle and Tip or, the
equivalent in Binks.

d. Drying time is one hour (dust free), but will require 400 °F temperature before it cures completely. Curing with topcoat
applied can be accomplished by normal operation of the suppressor.

e. Apply one coat with a dry film thickness of 2.5 mils. A dry film of 2.5 mils will require a 5.0 mil wet film thickness.

f. Briner coatings are available from:

Briner Paint Mfg. Company

3713 Agnes Street
Corpus Christi, TX 78405
(512) 884-4804

6.6.4 Heat Resistant Silicone Coating-Briner 2986. Instructions for applying Briner 2986 are as follows:

NOTE

Briner 2986 shall be used only as a topcoat for Briner 2905 or Briner 4765.

a. Briner 2986 is a one component, black, heat resistant silicone coating. The material is ready mixed, but should be
thoroughly stirred before use.

b. Thinning can be accomplished using Briner 70 Silicone Reducer.

c. Apply Briner 2986 by brush, conventional spray, or airless spray.

Conventional Airless Airless

78, 765, 704 Air cap with E 0.017-inch tip at 1,700
or EX needle and tip. De Pounds
Vilbiss MBC-510 Gun or the
equivalent in Binks

d. Briner 2986 will not cure without 350-400 °F for 1 hour. The coating will not cure during normal operation of the
suppressor.

e. Two coats at 1.5 mils each of dry film are recommended. A dry film of 1.5 mils will require a 4.5 mil wet film thickness.

6.6.5 High Temperature Resistant Silicone Coating-Briner 4765. Briner 4765 is a two component, gray, high tempera-
ture resistant silicone coating.

a. The zinc powder must be mixed into the SE before using.

b. Thinning should not be necessary but Briner 4765 can be thinned with Briner 70 silicone reducer.

c. Apply Briner 4765 by conventional spray. De Vilbiss MBC-510 Gun, 704 Air cap, an E needle and tip or the equivalent
in Binks.

6-3
TO 35-1-3

d. Drying time is one hour (dust free). Curing with topcoat applied can be accomplished by normal operation of the
suppressor.

e. Apply one coat of Briner 4765 with a dry film thickness of 2.5 mils; this will require a wet film thickness of 5.0 mils.

6.6.6 High Temperature Resistant Silicone Coating Thurmalox 270-18. Instructions for applying Thurmalox 270-18
are as follows:

NOTE

Thurmalox 270-18 shall be used as a topcoat for MIL-PRF-23236, Type I.

6.6.6.1 Thurmalox 270-18 is low-sheen green, one-component, heat resistant coating of silicone resin.

6.6.6.2 Mix to a uniform consistency by ordinary stirring.

6.6.6.3 Thinning can be accomplished using Thurmalox 295 thinner. Do not use more than 1-1/2 pints per gallon.

6.6.6.4 Apply Thurmalox 270-18 by airless, conventional, or electro-static spray equipment. The following equipment is
recommended by the manufacturer as a guide:

Spray gun DeVilbiss P-MBC or JGA

Air hose 5/16 in Inside Diameter
(ID)
*Fluid hose 3/8 in (ID)
Air cap 704
Fluid nozzle FX (0.042 inch)
Pot pressure 15-20 pounds
Atomizing pressure 40-45 pounds
Needle adjustment Half open
Distance from work 8-10 inch
* Smaller hose diameters, or hose lengths greater than 25
feet, may make it necessary to increase pressures.

6.6.6.5 Drying time at 77 °F, set to touch, is 30 minutes.

6.6.6.6 Dry film thickness should be 1.0 mil.

6-4
 TO 35-1-3

CHAPTER 7
SOUTHWEST ASIA OPERATIONS AND ENVIRONMENTS
7.1 GENERAL.

The Southwest Asia (SWA) Area of Responsibility (AOR) consists of various regions from Afghanistan to South Africa
(Figure 7-1). The environmental conditions range from seasonal high winds and high humidity to arid areas and low winds. In
many locations, there are negatively charged ions called anions in soils which when combined with aggressive sand storms,
can spread through SWA. The degree that sand and dust can penetrate equipment is dependent on many variables such as
wind speed and direction, size of the dust/sand particles, protective shelter availability, and condition of the equipment, such
as deteriorated seals/gaskets and bent doors.

TO-35-1-3-126

Figure 7-1. SWA AOR

7.1.1 Environmental Effects. Extensive operations in a desert can result in very fine sand and dust intrusion into support
equipment (SE). SE that is positioned in SWA for extended periods is more prone to exhibit significant corrosion problems.
Sandstorms, which are usually seasonal, can cause sand/dust to penetrate equipment and become entrapped in inaccessible
areas. During the periods of relative calm there are usually significant amounts of airborne dust, seen as a general haze, in the
atmosphere.

7.1.1.1 Soils and Humidity. Soils exposed to high humidity in many of the operating SWA AOR locations will cause
corrosion or accelerate existing corrosion growth if left in contact with metal surfaces. Even in arid areas, humidity is usually
present. During daylight hours, SE stored outdoors will heat up causing expansion of panels which allows hot, moist air to
migrate into enclosed areas (Figure 7-2) or under non-permeable equipment covers. When the equipment cools, the moisture
condenses and combines with the fine dust/sand particles, increasing the potential for corrosion. The soluble materials in the
dust/sand form a crust as they dry (Figure 7-3) making removal difficult. Anion-laden sand/dust entrapped in SE exposed to
high humidity will gather in the available moisture, extract the soluble salts, and a corrosion cell could be established. These
salts will appear as white streaks on SE after the water has evaporated off the units (Figure 7-3).

7-1
TO 35-1-3

TO-35-1-3-127

Figure 7-2. Sand/Dust Intrusion

TO-35-1-3-128

Figure 7-3. Residue from Salts Caused by Condensation

7.2 SE SWA AOR DEPLOYMENT.

7.2.1 Pre-deployment. Prior to deployment of SE to SWA AOR it is recommended that the following actions be taken to
prevent sand/dust intrusion during deployment.

a. Accomplish a complete SE wash per Chapter 2 prior to deployment.

b. Inspect entire exterior/interior surfaces for missing or deteriorated primer/paint.

c. Touch-up all deficient areas with approved processes and materials per Chapter 3.

d. Inspect and remove any standing water in unit.

e. Inspect and clean all drain holes.

f. Minimize lubrication by removing all excess greases/oils to limit sand/dust entrapment.

7.2.2 Deployment Location. Soils in SWA AOR locations should be considered suspect and removed on a regular basis. A
constant regimen of vacuuming or brush removal of sand/dust accumulations is necessary to reduce potential corrosion
problems.

7.2.2.1 SE Units Requiring Additional Cleaning. Some units require additional cleaning process due to air filters,
exposed lubrication areas, and areas that may be more prone to sand/dust entrapment.

7-2
 TO 35-1-3

7.2.2.1.1 Radiators, Vanes, Filters and Coils. SE that have radiators, vanes, filters, and coils require additional cleaning
to remove dust/sand that can block cooling ports and filters which are drawn into the units during operation. Clean using
engineering approved materials. Allow the units to dry in an enclosed area to prevent airborne sand/dust from adhering to wet
surfaces.

7.2.2.1.2 Portable Hydraulic Test Stands/Mobile Air Compressors. These units typically have interior fluid leaks that
will allow sand/dust to cling to the surfaces. Close inspection and wipe down of these units are necessary to maintain proper
operation.

7.2.2.1.3 Aircraft Jacks and Tow Bars. Jackscrew bodies and adjustable arms should be kept free of sand/dust at all
times. The use of locally manufactured permeable covers (Figure 7-4) will assist in prevention of sand/dust intrusion.
Lubricate units using corrosion preventive compound, MIL-L-87177, Type 1 to reduce corrosion problems.

TO-35-1-3-129

Figure 7-4. Locally Manufactured Permeable Covers

7.2.2.1.4 Open Circuit Boards/Cards. After cleaning open circuit boards/cards per TO 1-1-689-3, apply a thin coat of
avionics grade corrosion preventive compound, MIL-PRF-81309, Type III, to the board to insulate the circuits from sand/dust
intrusion.

7.2.2.1.5 Wire Bundles. Sharp angular sand/dust particles can migrate into wiring bundles where vibration caused by
equipment operation can result in abrasive action that can cause chafing of the wiring (Figure 7-5). Remove trapped sand from
around and between bundled wires to prevent electrical problems.

Figure 7-5. Wire Bundle Sand/Dust Accumulation

7-3
TO 35-1-3

7.2.2.1.6 Felt-Soundproofing Insulation. Periodically inspect areas where felt-soundproofing insulation is present for
moisture and/or sand/dust accumulations. Insulation found to be wet should be removed and allowed to dry before replacing
or replaced with new clean, dry insulation. Inspect areas behind insulation for corrosion or deteriorated coatings. Repair areas
as required prior to reinstalling installation.

7.2.3 Maintenance Touch-Up Painting. Maintenance touch-up painting of small areas should be accomplished when bare
metal surfaces are exposed to prevent further deterioration and protect against corrosion. Touch-up painting should only be
accomplished using approved touch-up materials listed in Chapter 3.

7.2.3.1 Temporary Coating Repair. Temporary coatings are to be used to protect the surfaces until the unit can be
permanently repaired as required. Corrosion preventive compound, MIL-DTL-85054 is a water displacing Corrosion
Preventive Compound (CPC) that forms a clear, dry, flexible film on the surface. This is temporary and will require reapplica-
tion as needed. Refer to Chapter 3 for application and removal instructions.

7.2.3.2 Permanent Authorized Touch-Ups. For permanent touch-up of small areas use only authorized coating systems
listed in Table A-1. The use of primer and topcoat are required for permanent touch-ups.

7.2.4 Equipment Storage. In the harsh environments of SWA it is recommended that SE be stored indoors or under
covers. Permeable fabric covers are recommended for short and long-term storage of equipment. These covers can be
purchased or locally manufactured. They allow for airflow to prevent condensation and sand/dust buildup on/in the equip-
ment.

7-4
 TO 35-1-3

APPENDIX A
EQUIPMENT AND CONSUMABLE MATERIALS USED FOR CORROSION
CONTROL
A.1 EQUIPMENT AND CONSUMABLE MATERIALS.

Table A-1. Equipment and Consumable Materials List

Nomenclature/Description Specification Stock Number Unit of Issue

• The following Room Temperature Vulcanizing (RTV) silicone sealants are corrosive and will not be used on
ground support equipment: DC Silastic 730 RTV, 732 RTV, 734 RTV, 736 RTV, 784 RTV, 1890 RTV; DC 781
RTV, 4-2817, 90406 RTV, 93-006 RTV, 96-081 RTV, GE RTV 102, RTV 103, RTV 106, RTV 108, RTV 109,
RTV 112, RTV 116, RTV 118, RTV 157, RTV 159, RTV 1502, RTV 1503, RTV 1508.

• The following RTV silicone sealants are corrosive and have been discontinued but may be remaining in the
supply system. These sealants will not be used on ground support equipment: DC Silastic 140 RTV, 142 RTV,
731 RTV, 785 RTV, 891 RTV; DC 236 RTV, 780 RTV, 3144 RTV, 20-046 RTV, 20-078 RTV, 30-079 RTV,
30-121 RTV, 90-092 RTV, 92-005 RTV, 92-007 RTV, 92-009 RTV, 92-018 RTV, 92-024 RTV, 92-048 RTV,
92-055 RTV, 93-043 RTV, 94-002 RTV, 94-003 RTV, 94-009 RTV, 94-034 RTV, 96-005 RTV, 96-080 RTV,
Q3-6069 RTV GE RTV 154, RTV 156, RTV 158, RTV 192, RTV 198.

Abrasive Blasting MIL-PRF-9954

Media, Glass Beads Sieve Size 8 5350-00-012-1869 Container (50
pounds
Sieve Size 10 5350-00-110-2981 Container (50
pounds)
Sieve Size 13 5350-00-576-9634 Container (50
pounds)
Sieve Size 2 5350-00-935-7697 Bag (50 pounds)
Sieve Size 3 5350-00-935-7698 Container (50
pounds)
Sieve Size 6 5350-00-950-9766 Container (50
pounds)
Sieve Size 12 5350-01-023-0302 Bag (50 pounds)
Sieve Size 5 5350-01-368-6707 Bag (50 pounds)
Sieve Size 1 5350-01-565-8141 Container (50
pounds)
Adhesive-Sealant Silicone, Room MIL-A-46146
Temperature Vulcanizing Type I White 8030-00-938-1535 Tube
Non-corrosive Type I White 8040-00-118-2695 Tube
Type I White 8040-00-938-1535 Tube
Type I, (High Strength) 040-00-117-8510 Tube
Type I, (High Strength) 040-00-144-9774 Cartridge
Type I, (High Strength) 8040-00-145-0020 Tube
Alcohol, Isopropyl TT-I-735 6810-00-753-4993 Can
6810-00-983-8551 Quart
6810-00-286-5435 Gallon

A-1
TO 35-1-3

Table A-1. Equipment and Consumable Materials List - Continued

Nomenclature/Description Specification Stock Number Unit of Issue

Applicator, Corrosion Preventive The non-stocklisted Formit spray 6850-01-492-2942 Dozen
Compound (CPC) FORMITÒ 90 wands are described with the
degree angle middle number being the length
Formit-18-360 Part Number (PN) of the spray can wand. The second Non-stock listed Dozen
006227 designator is the type of spray
Formit-18-F PN 006224 pattern issuing from the wand Non-stock listed Dozen
such as 360 is a full circle, F is a
Formit-18-FOG PN 008352 fan, and FOG is a fine mist. Non-stock listed Dozen
Formit-18-90-FOG PN 009134 STD-FOG signifies the fogging Non-stock listed Dozen
Formit-18-180 PN 006226 spray comes from the center of Non-stock listed Dozen
Formit-36-F PN 009130 the spray-head. The 90-FOG Non-stock listed Dozen
signifies the spray comes from the
Formit-36-360 PN 009131 Non-stock listed Dozen
side of the spray head. Formit
Formit-48-STD-FOG PN 009133 applicators may be obtained from Non-stock listed Dozen
Formit-48-360 PN 009132 Zip-Chem Products, 1860 Dobbin Non-stock listed Dozen
Formit-48-90-FOG PN 009134 Drive, San Jose, CA 95133,1-800-
648-2661
Barrier Material, Water Vapor- MIL-PRF-121, Grade A, Type 2, 8135-00-753-4661 Roll
proof, Flexible, 36 inch Class I
Barrier Material, Water Vapor- MIL-PRF-131, Class I 8135-00-282-0565 Roll
proof, Flexible, Heat Sealable, 36
inch
Cleaner, Pipe 840507 9920-00-292-9946 Package
Cleaning Compound, Aerospace MIL-PRF-87937, Type I 6850-01-390-7808 Gallon
Equipment 6850-01-390-7811 Can
6850-01-390-7816 Drum
6850-01-390-7821 Bulk
MIL-PRF-87937, Type III 6850-01-390-9530 Gallon
6850-01-390-9453 Drum
6850-01-390-9558 Bulk
MIL-PRF-87937, Type IV 6850-01-429-2368 Gallon
6850-01-429-2371 Drum
Cleaning Compound, Aircraft MIL-PRF-85570, Type I 6850-01-237-7482 Can
Exterior
6850-01-237-8003 15 Gallon
6850-01-237-8004 Drum
MIL-PRF-85570, Type II 6850-01-239-0571 Gallon
6850-01-235-0872 Can
6850-01-248-9828 15 Gallon
6850-01-236-0128 Drum
MIL-PRF-85570, Type III 6850-01-232-9164 Can
MIL-PRF-85570, Type IV 6850-01-235-0873 Can
6850-01-248-9829 15 Gallon
6850-01-248-9830 Drum
MIL-PRF-85570, Type V 6850-01-234-0219 Can
6850-01-248-9831 15 Gallon
6850-01-235-7458 Drum
Coating, Polyurethane, Flat Thousand
Advanced Performance Coating/
Extended Life Topcoat
36118 Gray 99GY013 8010-01-501-5577 Box

A-2
 TO 35-1-3

Table A-1. Equipment and Consumable Materials List - Continued

Nomenclature/Description Specification Stock Number Unit of Issue

37038 Black 99BK004 8010-01-501-5590 Box
Coating, Polyurethane, Flat MIL-PRF-85285, Type IV, Color
Touchup Brush per SAE-AMS-STD-595
31136 International Red Non-stock listed Box
33538 International Yellow Non-stock listed Box
35044 Dark Blue Non-stock listed Box
36118 Gray Non-stock listed Box
37038 Black 8010-01-583-1744 Box
37875 White Non-stock listed Box
Coating, Polyurethane, Gloss, MIL-PRF-85285, Type IV, Color
Preval Power Pack Spray System per SAE-AMS-STD-595
11136 Insignia Red Non-stock listed Box
12197 International Orange 8010-01-501-5573 Box
13538 Yellow Non-stock listed Box
15044 Dark Blue Non-stock listed Box
16473 Light Gray Non-stock listed Box
17038 Black 8010-01-501-5575 Box
17925 White 8010-01-501-5576 Box
Coating, Polyurethane, Gloss MIL-PRF-85285, Type IV, Color
Touch-up Brush per SAE-AMS-STD-595
Clear Non-stock listed Box
11136 Insignia Red 8010-01-583-1754 Box
12197 International Orange 8010-01-583-1571 Box
13538 Yellow 8010-01-583-1746 Box
15044 Dark Blue 8010-01-583-3831 Box
15050 Dark Blue Non-stock listed Box
16473 Light Gray Non-stock listed Box
17038 Black 8010-01-583-1750 Box
17925 White 8010-01-583-1753 Box
Coating, Polyurethane MIL-PRF-85285, Type IV, Color
per SAE-AMS-STD-59
26173 Gray, Semi-Gloss 8010-01-621-3102 Kit (2 Quart)
8010-01-621-3056 Kit (2 Gallon)
24052 Marine Green, Semi-Gloss 8010-01-520-4042 Kit (Quart)
8010-01-621-3045 Kit (2 Gallon)
37038 Black, Flat 8010-01-520-4055 Kit (Quart)
8010-01-583-4823 Kit (2 Gallon)
11136 Insignia Red, Gloss 8010-01-583-4778 Kit (2 Quart)
8010-01-583-6588 Kit (2 Gallon)
14187 Oxygen Tank Green, Gloss 8010-01-583-4774 Kit (2 Quart)
8010-01-583-4801 Kit (2 Gallon)
16187 Mechanic Gray, Gloss Non-stock listed Kit
17925 White, Gloss 8010-01-520-4041 Kit (2 Quart)
8010-01-502-5202 Kit (Gallon)
Coating, Polyurethane, Semi- MIL-PRF-85285, Type IV Color
Gloss, Touch-up Brush per SAE-AMS-STD-595
26173 Gray Non-stock listed Box
24052 Marine Green Non-stock listed Box

A-3
TO 35-1-3

Table A-1. Equipment and Consumable Materials List - Continued

Nomenclature/Description Specification Stock Number Unit of Issue

Coating, Polyurethane, MIL-PRF-85285, Type IV, Color
2-Component Aerosol per SAE-AMS-STD-595
37038 Black, Flat 8010-01-583-2233 Box
26173 Gray, Semi-Gloss Non-stock listed Box
24052 Green, Semi-Gloss Non-stock listed Box
11136 Red, Gloss 8010-01-583-2268 Box
Coating, Primer, Epoxy, High MIL-PRF-23377, Type I, Class N 8010-01-592-7874 Kit (Pint)
Solids
8010-01-555-3386 Kit (Quart)
8010-01-555-3381 Kit (Gallon)
Coating, Primer, Epoxy, High MIL-PRF-23377, Type I, Class N 8010-01-651-1507 Box
Solids, Touch-up Brush
Coating, Primer, Epoxy, High MIL-PRF-23377, Type I, Class N Non-stock listed Box
Solids, 2-Component Aerosol
Coating, Primer, Epoxy, Corro- MIL-DTL-53022, Class L, Type 8010-01-610-7328 Kit (Quart)
sion Inhibiting, Lead and IV
Chromate Free
8010-01-589-7077 Kit (Gallon)
8010-01-588-4312 Kit (5 Gallon)
Coating, Primer, Metal-Rich MIL-PRF-32550, Type I, Form A, 8010-01-467-4551 Kit (Gallon)
Class S
Coating, Preservative Rubber A-A-52408 (MIL-P-11520) 8030-01-282-5626 Gallon
Coating, Walkway Compound A-A-59166
Nonslip
36231 Dark Gray, Flat 5610-00-641-0426 Gallon
36440 Light Gray, Flat 5610-00-141-7842 Gallon
37038 Black, Flat 5610-00-641-0427 Gallon
Corrosion Preventive Compound MIL-PRF-16173, Grade 4, 16 8030-00-142-9281 Can
ounce aerosol
Corrosion Preventive Compound MIL-PRF-16173, Grade 2 Non-stock listed Can
Corrosion Preventive Compound MIL-PRF-81309, Type II, 16 8030-00-938-1947 Can
ounce aerosol
Corrosion Preventive Compound MIL-PRF-81309, Type III, 16 8030-00-546-8637 Can
ounce aerosol
Corrosion Prevention Compound MIL-DTL-85054, Type I, 6850-01-492-2932 consists Box
(aerosol) COR-BAN 35 of 12 (16 ounce) cans to a
box
Corrosion Prevention Compound MIL-DTL-85054, Type I, 8030-01-531-7358 consists Box
(aerosol) COR-BAN 35 of 12 (12 ounce) cans to a
box
Corrosion Prevention Compound MIL-DTL-85054, Type I, 8030-01-347-0980 consists Can
(aerosol) of a single 11 ounce can
Corrosion Prevention Compound MIL-DTL-85054, Type I, (bulk) 8030-01-615-4737 consists Box
COR-BAN 35 of 12 (1 Quart) cans
Corrosion Prevention Compound MIL-DTL-85054, Type II, (bulk) 8030-01-531-7360 consists Can
COR-BAN 35 of a single 5 Gallon can
Corrosion Prevention Compound MIL-DTL-85054, Type II, (bulk) 8030-01-615-4749 consists Box
COR-BAN 35 UNDYED of 12 (1 Quart) cans
Corrosion Prevention Compound MIL-DTL-85054, Type II, (bulk) 8030-01-615-4740 consists Box
of 4 (1 Gallon) cans

A-4
 TO 35-1-3

Table A-1. Equipment and Consumable Materials List - Continued

Nomenclature/Description Specification Stock Number Unit of Issue

Corrosion Prevention Compound MIL-DTL-85054, Type II, (bulk) 8030-01-347-0981 consists Quart
of a single Quart can
Corrosion Preventive Compound, MIL-PRF-63460D 9150-01-079-6124 Bottle
Lubricant, Cleaner, and Preserva- 9150-01-054-6453 Pint
tive for Weapons and Weapons 9150-01-327-9631 Quart
Systems (CLP)
Corrosion Preventive Compound, MIL-L-87177A 6850-01-328-3617 Can
Electronics Grade with VCI
Disc, Clean ’N Strip, 3 inch 5345-01-070-0447 Each
Disc, Rubber Wheel, 4 inch PN 07498 5345-01-549-0264 Each
Eraser, Typewriter 7510-00-619-7714 Each
Eraser, Pencil Ruby Red 7510-00-223-7046 Each
Film, Abrasion Resistant Scotch 9330-00-124-3730 Roll
Brand Polyurethane
Mandrel, For Disc 3460-00-150-7164 Each
Pad, Abrasive, Non-woven, A-A-58054
Non-metallic Grade A (Very Fine) 5350-00-967-5089 Box
Grade B (Fine) 5350-00-967-5093 Box
Grade C (Medium) 5350-00-967-5092 Box
Paper, Abrasive Aluminum Oxide, 240 Grit 5350-00-224-7205 Package
Non-waterproof 320 Grit 5350-00-246-0330 Package
Paper, Abrasive Silicon Carbide, 320 Grit 5350-00-867-7665 Package
Waterproof
Paper, Abrasive, Silicon Carbide, 180 Grit
Disc, Pressure Sensitive Backing 3M (05114-01469) 5345-01-074-9404 Roll
280 Grit
3M (058144-01466) 5345-01-074-9406 Roll
Pneumatic Vibrogun Sealant PN 8400K, Commercial and 5130-01-514-0853 Each
Removal Kit, Envision Pneumatic Government Entity (CAGE) Code
(Includes: 1 Ea Ingersoll Rand #65956
1,000 RPM Right Angle Drive,
1/4 in Threaded Chuck Pneumatic
Drill Motor; 1 Tube with 5 Each
#8 SR Cutters; and 1 Tube with 5
Each #3 SR Cutters
Pretreatment Aluminum, MIL-DTL-81706 SEMPENS 8030-01-460-0246 Case
Chromate Conversion Coating
Primer, Waterborne Epoxy
Remover Sealant, SkyKleenÒ Non-stock listed Gallon
1,000
Sealing Compound, Low PR-1733
Adhesion, Polysulfide (Note the B-1/2 8030-01-418-5415 Sealing Compound
number next to the B reflects the B-1/2 8030-01-418-5418 Sealing Compound
working time of the sealant)
B-2 8030-01-418-5415 Sealing Compound
Sealing Compound, Self Level-
ingTM
For filling voids/cavities on HT3326-5-50 8030-01-494-9650 Cartridge
horizontal surfaces where water
collects

A-5
TO 35-1-3

Table A-1. Equipment and Consumable Materials List - Continued

Nomenclature/Description Specification Stock Number Unit of Issue

Sealing Compound, ThioflexTM PN TF2219 8030-01-494-7677 Cartridge
Orange Polyurethane Sealant For
filling voids/cavities on vertical
and overhead surfaces
Sealing Compound, PN DC-111 6850-00-294-0860 Each
Sealant, Low Adhesion and AMS 3267/PR1403G
Corrosion Inhibiting Class B-2 (Paste) 8030-01-104-5396 Kit
Sealant, MIL-PRF-81733 8030-00-008-7205 Tube
Sealant, AMS-S-8802 Fuel Cell Use Only 8030-00-723-5344 Tube
Sealant Removal System, RDS001, CAGE Code #3FM31 6635-01-572-5251 Each
Aerowing rapid desealing system
(Includes: 0.5 inch/inches removal
tip (Pack of 10), 2 inch/inches
Shaft, Shaft removal Tool,
Operator’s Manual)
Solvent, Dry Cleaning MIL-PRF-680, Type II or CID 6850-00-110-4498 Pint
A-A-59601 6850-00-637-6135 Gallon
6850-00-274-5421 Can
6850-00-285-8011 Drum
MIL-PRF-680, Type III or CID 6850-01-331-3349 Can
A-A-59601 6850-01-331-3350 Drum
MIL-PRF-32295, Type II 6850-01-606-8356 Gallon
6850-01-606-8357 5 Gallon
6850-01-606-3293 15 Gallon
6850-01-606-8358 55 Gallon
(As an alternate method) use a
(5PC-local purchase) 3m Rubber
wheel, part number 07498 for
removing vinyl reflectors and
vinyl stencils from equipment
Spray Kit, Preval with Com- 267-1 8020-01-501-3127 Each
pressed Gas Canister and Glass
Bottle
Spray Kit, Preval Spray Com- 268-1 8020-01-496-2473 Each
pressed Gas Canister
Tape Pressure Sensitive SAE-AMS-T-23397, Type II
1/2-inch 7510-00-476-8841 Roll
1-inch 7510-00-473-9855 Roll
2-inch 7510-00-473-9513 Roll

NOTE

• SEMPENs are approved for touch-up on polyurethane surfaces. Respirator use is not normally required;
however, organizations shall gain approval from the local bioenvironmental engineer prior to using the
SEMPEN without a paint respirator.
• Preval Spray System/Power Pack Spray Systems are atomizing paint touchup spray systems. Personal
Protective Equipment (PPE) shall be worn when spraying polyurethane and epoxy primer.

• Single component aerosols are not authorized for use on any SE.

A-6