SURFACE PREPARATION STANDARD

The reference standards for abrasive blasting shall be SIS 05-59-00, ISO 8501-1, SSPC -Vis 1
& NACE

Blast-cleaning, Sa. ISO 8501-1

Surface preparation by blast-cleaning is designated by the letters “Sa.”

Prior to blast-cleaning, any heavy layers of rust shall be removed by chipping. Visible oil, grease
and dirt shall also be removed.
After blast-cleaning, the surface shall be cleaned from loose dust and debris.
NOTE - For descriptions of surface preparation methods by blast-cleaning, including treatment
prior to, and after, the blast-cleaning procedure, see ISO 8504-2.

Sa 1 Light blast-cleaning.
When viewed without magnification, the surface shall be free from visible oil, grease, and dirt,
and from poorly adhering mill scale, rust, paint coatings and foreign matter.

Sa 2 Thorough blast-cleaning.
When viewed without magnification, the surface shall be free from visible oil, grease, and dirt,
and from most of the mill scale, rust, paint coatings and foreign matter. Any residual
contamination shall be firmly adhered to.

Sa 2-1/2 Very thorough blast-cleaning.

When viewed without magnification, the surface shall be free from visible oil, grease, and dirt,
and from mill scale, rust, paint coatings and foreign matter. Any remaining traces of
contamination shall show only as slight stains in the form of spots or stripes.

Sa 3 Blast-cleaning to visually clean steel.

When viewed without magnification, the surface shall be free from visible oil, grease, and dirt,
and shall be free from mill scale, rust, paint coatings and foreign matter. It shall have a uniform
metallic color.

Hand and power tool cleaning, St.

Surface preparation by hand and power tool cleaning, such as scraping, wire brushing, machine-
brushing, and grinding, is designated by the letters “St”.

St 2 Thorough hand and power tool cleaning.

When viewed without magnification, the surface shall be free from visible oil, grease, and dirt,
and from poorly adhering mill scale, rust, paint coatings and foreign matter.

St 3 Very thorough hand and power tool cleaning.

As for St 2, but the surface shall be treated much more thoroughly to give a metallic sheen
arising from the metallic substrate.
Fl Flame Cleaning.
When viewed without magnification, the surface shall be free from mill scale, rust, paint
coatings and foreign matter. Any remaining residues shall show only as a discoloration of the
surface (shades of different colors).

SSPC -Vis 1 & NACE

SSPC SP 1 Solvent Cleaning
SSPC SP 7 NACE No. 4 Brush Off Blast Cleaning
Brush Off is specified to remove loose rust, mill scale and coatings, and uniformly roughen up a
surface in preparation for a new coat. Tightly adherent materials are permitted to remain.
SSPC SP 14 NACE No. 8 Industrial Blast Cleaning (Sa 1)
Industrial Blast Cleaning specifies that 90% of the tightly adhered matter must go. Shadows,
streaks and stains from rust, mill scale, and old coatings are allowed on 100% of the surface
SSPC SP 6 NACE No. 3 Commercial Blast Cleaning (Sa2)
Commercial Blast Cleaning specifies that all tightly adhering matter must go. Shadows, streaks,
and stains can remain on up to 33% of the surface.
SSPC SP 10 NACE No. 2 Near White Metal Blast Cleaning (Sa 2.5)
Near White Blast Cleaning specifies that shadows, streaks, and stains must be limited to 5% of
the surface area. Near White is specified when the added benefit of blasting to White Metal
doesn’t justify the added expense.
SSPC SP 5 NACE No. 1 White Metal Blast Cleaning (Sa 3)
White Metal is the highest grade of abrasive blast cleaning. No shadows, streaks or stains are
permitted. When viewed without magnification, the surface shall be free of all visible oil,
grease, dust, dirt, mill scale, rust, coating, oxides, corrosion products and other foreign matter.

SSPC WATER JETTING STANDARD

Water jetting
Non-visible contamination (NV)
Visible surface cleanliness (VC)
 LP WC
 HP WC
 HP WJ
 UHP WJ

VIEL CHECK STANDARD

SSPC & ASTM Abrasive Cleanliness Standards
There are four SSPC Abrasive (AB) Standards:
1. SSPC-AB 1: Mineral and Slag Abrasives
2. SSPC-AB 2: Cleanliness of Recycled Ferrous Metallic Abrasive
3. SSPC AB- 3: Ferrous Metallic Abrasive
4. SSPC-AB 4: Recyclable Encapsulated Abrasive Media
5. ASTM D4940
6. ISO 11126
 Abrasive standards published by SSPC (AB), and ISO 11126 provide tolerance levels for water
soluble contaminants of the abrasive.
Each standard has different requirements based on the type of media but is identical.
When it comes to the quality control tests for oil content and water-soluble contaminants.
SSPC-AB 2 requires additional field and laboratory tests for cleanliness to help ensure the
abrasive recycling equipment is functioning properly and that the abrasive operating mix is still
adequately sized. SSPC AB-4 requires more frequent testing including at least three water-
soluble contaminant tests at different times during an 8-hour period.

ABRASIVE TESTING
While abrasive manufacturers often perform laboratory analysis of their product, their testing
does not fully satisfy the requirements of the SSPC abrasive (AB) standards since verification
testing for cleanliness is required in the shop or on the job site. Transporting, storing, and
recycling of the media can affect the cleanliness of the abrasive. The two tests that are used to
verify abrasive cleanliness in the AB standards are oil content and water-soluble salt content.
The contractor’s quality control inspector typically performs these tests, while the owner’s
quality assurance inspector verifies the testing is done correctly and documented.

According to the AB standards, the presence of oil contamination is determined in accordance

with ASTM D7393, Standard Practice for Indicating Oil in Abrasives. This shop/field test,
commonly known as the vial test, requires that a sample of abrasive be placed in a clean,
sealable container (about half the height of the container). Tap water (68 – 95°F) is added to
the container so that it is at least 1 inch above the abrasive. The container is shaken for 1
minute and allowed to stand for up to 5 minutes. The surface of the water is then visually
examined for any evidence of oil droplets or sheen. If oil is visually evident, the abrasive fails
the test. At least one test for each 50 bags of abrasive, or 3 tests per bulk delivery should be
conducted, as well as at least once per shift or every 12 hours (whichever is shorter) for
recyclable water remains cloudy,
the overall cleanliness of the abrasive should be questioned as this could impede production
and increase the amount of dust on the surface, especially when using metallic abrasives in a
centrifugal wheel machine, where static electricity causes it to adhere to the surface. abrasives.
This test also reveals whether the abrasive is excessively dirty. If dust floats to the surface or
the
Water soluble contaminants are the non-visible soluble salts that may be present on an
abrasive. The abrasive is tested in accordance with ASTM D4940, Standard Test Method for
Conductimetric Analysis of Water-Soluble Ionic Contamination of Blast Cleaning
Abrasives. According to the SSPC AB standards, the conductivity of the abrasive cannot exceed
1,000 µS/cm (micro-siemens/cm). This shop/field test requires combining equal parts abrasive
and deionized or distilled water (300 mL of each) and stirring twice for 1-minute each (with an
8-minute standing time between stirs). The purpose is to leach any soluble salts from the
abrasive. The extract from the water/abrasive slurry is then poured through filter paper to
prevent silt from fouling the probe of the conductivity meter. The conductivity of the filtrate is
then measured. It is important that the conductivity meter compensates for water temperature
and that the probe is verified for accuracy using a control solution (with a known conductivity
value) prior to use. An abrasive test kit (pictured) containing all the required equipment for the
analysis is available.

SURFACE PROFILE CHECK STANDARD

There are two ASTM standards that deal with surface profile assessment, ASTM D 4417,
Standard Test Methods for Field Measurement of Surface Profile of Blast Cleaned Steel,
ASTM D7127, Standard Test Method for Measurement of Surface Roughness of Abrasive Blast
Cleaned Metal Surfaces Using a Portable Stylus Instrument.

SURFACE DUST LEVEL CHECK STANDARD

ISO 8502-3 The tape indicates a pattern of adhered dust to the surface and is compared with
the pictorial figure provided on ISO 8502-3. The quantity of the dust classified 1 thru 5 with 1 as
lowest dust and 5 with the highest amount of dust.

SURFACE VISUAL CHECK STANDARD

All grease, oil fats or other deleterious substances shall be removed by chemical.
or solvent cleaning according to SSPC-SP1.

The use of reclaimed slag abrasives is prohibited. The use of reclaimed.

garnet is permitted for pre-blasting work provided it meets the
requirements of ISO 11126-7 and ASTM D7393 for oil contamination.

Inorganic zinc primer level of curing shall be checked by means of MEK rubbing test
to ASTM D-4275. Acceptance criteria: Rating 4 or 5.

Measurement of surface profile by Testex Press-O-Film or Digital Surface Profile

Gauge.

SALT CONTAMINATIION TEST STANDARD

ISO 8502-6 and 8502-9
After blasting, test the substrate for the chloride content. Residual chloride shall
not exceed 40 mg/m2 for external coatings and 20 mg/m2 for internal coatings.
Wash down the surface with sweet water to remove chloride contamination.
The chloride test shall follow the water wash down until the correct value is achieved.
In accordance with ISO 8502-6 and 8502-9 salt contamination.

WFT & DRY FILM THICKNESS CHECK STANDARD

 Wet film comb
 DFT Gauge (type 1) Magnetic pull off DFT gauges Not using in Onshore now.
 DFT Gauge (type 2)
The wet film thickness gauge is as essential companion to any instrument used to measure DFT.
Using the volume solids content of the coating, applicators can calculate the required WFT to
produce the desired DFT.

Use the wet film gauge according to on of the following national and international standards:
 AS/NZS 1580.107.3
 ASTM D 4414-A
 ISO 288-1A
 ASTM D 1212-A
 ISO 2808-1B
 NF T30-125
 US Navy NSI 009-32
 US Navy PPI 63101-000

Type 2 DFT Instruments Electronic gauges are called Type 2 gauges.
There are numerous standards that govern DFT measurement. The most used standards are:
 SSPC PA2
 ASTMD 7091
 ISO 19840
 IMO Resolution MSC.216 (82), Annex 3
Before using the gauge, verify the calibration accuracy by using it to measure coated thickness
standards.
A project specification may, however, require other standards. Inspectors must be careful to
use the specified standard. If the specification does not state a required standard, then it is
good practice to choose a standard, such as SSPC PA2, whose guidelines are broadly accepted
in the coatings industry.
SSPC PA2 requires five spot measurements (a minimum of three readings per spot are needed
to account for surface irregularities within the 1.5 in [4 cm ] circle of the spot; these readings
are averaged to arrive at a single measurement) for each 100 ft2 (10 m2) measured. Note that
individual readings are not subjected to rules but are included in the averages for a spot
measurement.
The average of the five spot measurements (i.e., at least 15 individual readings) can be no more
than the specified maximum thickness and no less than the specified minimum thickness.
No single spot measurement can be less than 80% of the specified minimum thickness and no
more than 120% of the specified maximum thickness.

ADHESION CHECK STANDARD

ASTM D3359 is standard test methods for measuring adhesion by tape test. This test assesses
the adhesion by applying and removing pressure-sensitive tape over cuts made in the film. This
test method is also known as the Cross Hatch test, Cross X Cut
ISO 4624 adhesion testing is a specific pull-off procedure that evaluates the durability of
protective coatings. The test is conducted by gluing a dolly to a metal surface with a protective
coating and applying it as external force to the dolly.

LOW VOLTAGE HOLIDAY STANDARD

 ASTN3894.2
 ASTM D 5162-A
 ASTM G6
 ASTMG62-A
 BS 7739-2
 ISO 8289 A
 ISO 14654
 NACE SP 0188
 NACE TM 0384
Holiday detectors are used to detect holidays of various kinds in coatings.
Not all types of structures or all industries use holiday detectors.
General types of holiday detectors include.
 Low-voltage DC
 High-voltage DC
 High voltage pulse DC
 High-voltage AC

Low Voltage Instruments

 Portable battery-powered electronic instrument
 Nonconductive handle with clamps (to hold sponge)
 Open-cell sponge (cellulose)
 Ground wire.
The low voltage holiday detectors shown are sensitive, low voltage, wet-sponge, electronic
device powered by 5-120V DC, depending upon the equipment manufacture’s circuit design.
Common voltages are use 9, 67.5, 90, and 120 V. They are reliable on coatings up to 20 mils
(500 µm) thick. These voltages are specified in NACE, ASTM, and ISO low voltage holiday
detection standards.
With the ground wire attached to the sub-state, wipe the coated surface with the wetted
sponge at a maximum rate of 1 liner foot per second (1fps) (30 cm/s).
Holiday testing is performed to find defects or discontinuities in coating film such as:
 Pinholes
 Fisheyes
 Cratering
 Nicks

HIGH VOLTAGE HOLIDAY STANDARD

 AS3894.1-2002
 ASTM G62-07
 ASTM D5162-08
 ASTM D4748-08
 NACE RP0274-04
 NACE SP0490-2007
 NACE SP0188-2006
 ANSI/AWWA C214-07
 ANSI/AWWA C213-07
 ISO 2746:1998
High Voltage Holiday
High Voltage pulse-type DC holiday detectors are designed to locate holidays in nonconductive
coatings that are applied over a conductive substrate. These instruments are ideal for use:
 In moist conditions
 ON wet coating surfaces
 On contaminated coating surfaces
 On carbon-impregnated coatings (i.e., carbonated rubber)
 On “plastic”/ fiberglass type coatings likely to become electrostatically charged
Set the voltage as stated in either the specification or the referenced standard. If no guidelines
are provided, the US industry’s rule of thumb is to use a voltage setting of:
 100 V/mil of coating thickness The European industry’s most-frequently used rule of
thumb is slightly different:
 4V/ µm of coating thickness The alternate methods to set the correct voltage is to
identify another type of defect, e.g., low DFT, or make a pinhole through the coating to
the substrate, then set the voltage at the lowest available setting on the unit.
Increase the voltage until it is sufficiently high to create a spark at the holiday. Use that
setting to inspect the coating for holidays.