CORROSION

1. Is the electrical circuit in a corrosion reaction AC or DC?

DC
2. Does corrosion occur at the cathode or at the anode?
Anode
3. Name three factors needed for corrosion to occur.
a) Electrolyte b) Anode C) Cathode
4. What is meant by the term electrolyte?
Electrolyte is a substance which will conduct a current and be broken by it (dissociate into ions)
5. What is corrosion?
Corrosion is the degradation of metals by chemical or electrochemical means.
6. In the corrosion circuit, do electrons flow from anode to cathode?
Electrons flow from Cathode to Anode.
7. Which gas is released at the cathode when the electrolyte is water?
Hydrogen Gas
8. Which is more noble metal, steel or aluminum?
Steel
9. Which is more electronegative, steel or aluminum?
Aluminum
10. If steel and copper were in contact in an electrolyte, which would corrode?
Steel
11. Name two common Hygroscopic salts
a) Sulphate b) Chloride
12. Name three metals used as sacrificial anodes on steel pipelines.
a) Zinc b) Magnesium c) Aluminum
13. What is the approximate thickness of millscale?
25 to 100 microns
14. Which of the two metals would corrode if steel and zinc were coupled?
Zinc
15. Which other names relate to Galvanic List?
Electro-Chemical Series
16. In which environment are you likely to encounter chloride salts?
Marine Environment
17. Which three compounds together to form millscale?
Wustite, Magnetite and Haematite
18. If magnesium was coupled with zinc, which would corrode?
Magnesium
19. In which environment would sulphate salts be found?
Industrial Environment
20. What is an osmotic blister?
Pinhead sized water filled blister

1
21. What is an ion?
A charge particle and can be positively or negatively charge.
22. What is meant by polarization?
Polarization is the joining together of a string or structure of repeated units.
23. Is an anode positive or negative?
Positive
24. Can corrosion occur without electrolyte?
No
25. Name a sub-atomic particle
Molecule
26. What is millscale and where does it occur?
Millscale are compounds of iron formed during the rolling operation of steel sections at
temperature in excess of 580oC.
27. Name three factors which can accelerates corrosion reactions.
A) Temperature b) Hygroscopic Salts c) Aerobic Conditions
28. What is considered essential to remove millscale prior to painting?
Surface Preparation
29. Why does an uncoated steel plate corrode?
If the uncoated steel plate is exposed to the atmosphere, moisture and any chemicals in the
atmosphere will combine to form electrolyte on the surface of the plate. Under normal
conditions, iron atoms at the anodic surfaces release electrons as part of the corrosion circuit.
These atoms become ferrous ions, which reacts with negative hydroxyl ions that are produced at
the cathode. The reaction in the electrolyte between the ferrous ions and hydroxyl ions results in
the surface of layer of iron oxides (rust) on the steel surface.
30. If corrosion occurs at an anodic area, why is steel corrode evenly all over the surface?
Electrons flow from the anodic area through the steel plate to the cathodic area. A steel plate can
have many millions of corrosion cells and may give appearance of rusting uniformly over its
entire surface.

2
SURFACE PREPARATION
A
1. Which British Standard would be used in determining the size of copper slag abrasive?
BS 7079 pt E
2. Which British Standard would be used in determining the size of metallic abrasive
BS 7079 pt E
3. Which regulations prohibit the use of sand for blasting steel?
COSHH REGS
4. What is meant by the term “Key”?
An expression referring to the cross section of a blasted area, as measured from the top of the
peak to the bottom of the trough.
5. Why is it important to have a good surface preparation?
In order to have a good adhesion of the coating and achieve a coating life satisfactorily
6. What is meant by the term Sliver?
Other term for Lamination, a longitudinal crack, one lip curling back
7. What is a Hackle?
A small surface lamination which stands upright like a needle after blasting.
8. Name two other terms that could be used for anchor pattern?
a) Surface Profile b) key
9. What are the main advantages of using “Testex Papers for measuring profiles?
It provides a permanent record and the traceability required from the quality systems.
10. What is meant by the term grade, relating to a blast finish?
It relates to how much contaminant is left on the surface after preparation.
11. What are the main factors governing the grade of a blast finish?
Time spent on the area to be cleaned and velocity of the particles.
12. Can a grade of a blast finish be determined by using the surface comparators to BS 7079 Pt C3?
Yes
13. What profile range can be measured using “X coarse” Testex?
37-115 microns
14. What profile range can be measured using coarse grade Testex?
20-50 microns
15. What are the two theories of adhesion?
Molecular Interference and Molecular Attraction
16. Briefly describe the mechanisms of the two theories of adhesion.
a) Molecular Interference- because the surface is rough and uneven, the paint wets, and
locks into the profile
b) Molecular Attraction- Negatively charged particles attracted to positive areas
17. How many microns in 1 thou?
25 microns
18. Give three different names for the cross section of a blast.
a) Surface Profile b) Anchor Pattern c) key
19. What is the approximate speed of abrasive leaving venturi nozzle?
450 mph

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20. What is the most common cause of flash rusting on a blasted substrate?
Presence of rogue peaks in concentrated areas.
21. What would be considered to be an ideal shot-grit mix?
70 -80% Shot to 20-30% Grit
22. What is the purpose of mixing shot and grit?
Mixing shot and grit would result to a more uniform profile
23. Which abrasive would have the effect of work hardening in a substrate?
Steel Shot
24. Name three methods of measuring or assessing a profile.
a)Surface Profile Needle Gauge b) Dial Micrometer c)comparators
25. What is the most common cause of rogue peaks on a substrate?
Uncontrolled peak height
26. In what situation would it be better to use steel grit in preference to copper slag abrasives?
Copper slag is expendable while steel grit can be recycled.
27. If cracks or lamination are found on a substrate after blasting, what steps should be taken?
It must be referred to engineer for ultrasonic check
28. Using comparators to ISO 8503, what are the three main profile assessments?
a)Naked Eye b) Visual Aid not exceeding 7x c) Tactile
29. What are the other two assessments when the above three are not appropriate?
a) Finger nail b) clean wooden stylus
30. What would be the size of copper slag needed to give a profile of 50 to 75 um?
0.05mm to 0.075mm

B.

1. What is the title of B.S. 7079?

Specification for assessing a profile
2. What are the four characteristics of abrasive?
a)Shape b)Hardness c)Density d)Size
3. Why are blast hoses carbon impregnated?
To reduce the chance of the operator getting electric shock from static.
4. Name the gauge used for measuring pressure at the blast nozzle
Hypodermic Needle Gauge
5. Name four advantages of centrifugal over open blasting
a) The quality of blasting can be controlled
b) More operators safety because the operator is not involved
c) The system can be more productive
d )Because the system is closed, there is efficient use of abrasives.
6. According to BS 7079, is it possible to blast clean over an A Sa1?
Not possible.
7. Is there any difference between A Sa1 and B Sa1?
Degree of Cleanliness or amount of contaminant left on the surface after preparation.
8. Could you tell the difference between an A Sa1 and B Sa1?
Blast cleaning can be achieved over BSa1 while not on ASa1.
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9. Could you please tell the difference between rust grade C and D blasted to Sa3?
Slight pitting is visible on rust Grade C while general pitting is visible on rust Grade D before
blasting to Sa3. Rust grade D requires more time to blast on Sa3 compared to rust Grade C.
10. What would be the typical speed of abrasive leaving a wheelabrator?
220 mph approx.
11. What is considered to be the most efficient blasting pressure?
100 psi
12. What is meant by the term burnishing?
Polishing
13. What would be the equivalent of St2 in the Sa grades?
Sa1
14. What is the neutral figure on the pH scale?
7
15. What is the meaning of pH and how it is measured?
pH is a measure of acidity and alkalinity of a substance and it is measured usin pH indicator
strips.
16. Why are inhibitors sometimes added to water in wet blasting?
To retard the formation of corrosion products.
17. Name two typical areas where needle guns might be used?
a) Limited access b) environmental consideration
18. What is the Duplex process of surface preparation?
A process involving pickling process followed by passivation process using Phosphoric or
Chromic Acid with a small percentage of iron filling.
19. Which pH range covers acid, and which range covers alkalis?
pH range=1-7 ; Alkalis Range= 7-14
20. Name two areas on a structure where flame cleaning cannot be done?
Nuts and bolts; rivets
21. Which three basic operations are performed during flame cleaning?
a) Dehydration b) Expansion c) Penetration
22. How does BS 7079 define Flame Cleaning standards?
AFl, BFl, CFl, DFl
23. What is Jasons Hammer?
Hand operated tool
24. What is meant by St2 and St3?
St2- Thorough hand and power tool cleaning
St3- Very thorough hand and power tool cleaning
25. Two alloys are used to render wire brushes, “spark free”, what are they?
a) Phosphor Bronze b) Beryllium Bronze
26. Why should “Burnishing” be avoided?
It does not provide good adhesion

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27. Name two major disadvantages of using a needle gun
a) It tends to leave a very coarse profile
b) Needs to be reduced by abrading with emery or grinding
28. After phosphating, what should be a typical pH requirement prior to coating?
pH= 4.5 – 7.0
29. What is understood by the term “knockout pot”?
Vapour traps for oil and water
30. If an operator was blasting with a pressure of 80 psi, what would be his approximate efficiency?
80%
31. Which solvents are commonly used for degreasing?
Xylene and clean water
32. What is a “dead man’s handle”?
A safety equipment under operator control for his own safety.
33. How is abrasive cleaned in an abrator system?
The abrasive is gravity feed into the center of the wheelabrator . A centrifugal force carry it to
the end of the impeller where it is impelled at the component to be cleaned at a speed of 220
mph approx. in a fan pattern. A conveyer system then carries the abrasives to the top of the
machine, dispense it, to start gravity feed path back for re-used. As an integral part of the
system, An air wash separator is provided.
34. What is the main disadvantage of high pressure jetting compared to other system?
Operator fatigue and it will only clean up the original profile on rework areas.
35. Name five methods of wet blasting
a) High pressure water blasting up to 30,000 psi
b) High pressure plus abrasive injection
c) Low pressure plus abrasive injection
d) Steam cleaning
e) Air blasting with water injection.
36. What are the typical temperatures and concentration of sulphuric acid in the pickling process?
65- 70oC
37. Describe the Duplex Process.
a) Any oil or grease needs to be removed by using a suitable solvent
b) Totally immersed in a bath of Sulphuric Acid, 5-10% @ temperature bet. 65-70oC for a
period of 5-25 mins.
c) Rinse using clean warm water to remove the layers of soluble salts formed.
d) Immerse in a bath of phosphoric/chromic acid, 2% soln @80 oC for approximately 2 mins.
With iron filling (0.5%) and inhibitor to prevent embrittlement.
e) Rinse in clean water and check for pH values.
38. What would be the maximum pressure for high pressure water jetting?
30,000 psi
39. What are the disadvantages of wet blasting over dry blasting?
a) Supply of large amount of water
b) Disposal of resulting slurry
c) Mixing substrate inhibitors

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40. What would be considered to be advantages of wet blasting over dry blasting?
a) Environmentally friendly
b) Spark free from safety aspect
41. Why is phosphating or chromating of steel be done?
Rust prevention at a limited time
42. What would be an acceptable remedy for burnished areas?
Abrading with coarse emery
43. Would burnishing be expected on areas of St2 preparation?
No
44. How many photographs of blast cleaning standards are shown in BS 7079 Pt A?
4
45. Do the plates shown in BS 7079 Pt A relate to grit blasting or shot blasting?
Grit blasting.

7
PAINT TECHNOLOGY (1)
1. Name a third type of paint other than solvent free and solvent borne.
Powder Paint
2. An epoxy resin would use which solvent?
Ketones
3. Name four or more advantages of Chlorinated Rubber paints.
a) High resistance to mould growth.
b) Non-flammable after solvent release
c) Very resistant to chemical attack.
d) Very high resistant to high vapour transmission
e) Material is non-toxic
4. What are three main disadvantages of Chlorinate Rubber paints?
a) Low resistant to solvent as shown on the list of solvent compatibility
b) Low temperature tolerance, 65 deg C maximum
c) Spray application often results to cobwebs
5. Which solvent could be used with Phenolic Resin?
Aliphatic Hydrocarbons ie Solvent naptha
6. Chlorinated Rubber Paint would contain which solvent?
Aromatic Hydrocarbons
7. Would it be good practice to apply Chlorinated Rubber over Alkyd Resin?
No..lifting and wrinkling would result
8. Which solvent would be used with an Alkyd Resin?
Water or Aliphatic Hydrocarbons
9. How was the word Alkyd” derive?
Alcohol
10. What is meant by “opaque”?
Not transparent or translucent
11. What is meant by “vehicle”?
Consists of binders and solvent and other additives.
12. Would it be acceptable practice to apply an Alkyd over Chlorinated Rubber?
Yes
13. Would it be acceptable practice to apply Chlorinated Rubber over Phenolic?
No.
14. Would it be acceptable practice to apply Phenolic over Chlorinated Rubber?
Yes
15. Would it be acceptable practice to apply Epoxy over linseed oil base?
No.
16. Would it be acceptable practice to apply Chlorinated Rubber over Epoxy?
Yes
17. Would it be acceptable practice to apply Epoxy Resin over Alkyd Resin?
No.
18. What is the other name for an un-pigmented paint?
Dye Paint

8
 19. What are the natural properties of a Resin?
a) Fast drying b) Brittle c) Not soluble in water
20. What are the natural properties of Oil?
a) Drying b) Non-drying c)Semi-drying
21. How does paint using the barrier principle work?
The material forms a thick impermeable layer of high electrical resistance.
22. How does paint using the passivation principle work?
Causing a chemical reaction between a paint constituents and a substrate.
23. How does paint using cathodic protection principle work?
Employs the bi-metallic principles by using a less noble metal as pigmentation.
24. Give another name of solvent free two packs.
Multi Component Liquid (MCL)
25. Name six properties of a Binder.
a) Ease of application
b) Adhesion to substrate for the expected life of a coating.
c) Resistance ot abrasion
d) Resistance to chemical attack according to environment.
e) Cohesive strength, ability to hold together as a film
f) Dielectric strength.
26. Name three natural resins used in paints.
a) Copals b) dammars c) coumarones
27. Name five natural oils used in paints.
a) Linseed oil b) Tung oil c) Soya oil d) Tall oil e) Sunflower oil
28. What is oleoresinious mean?
Mixture of oil and resin
29. Name an Inorganic high temperature service binder.
Silicones
30. Name two pigments likely to be used for high temperature service.
a) Carbon b) Aluminium

PAINT TECHNOLOGY (2)

1. By what name would you call the basic unit of a polymer?
Mer
2. What is polymerization?
Joining together of string or structure of repeated units
3. Name three types of polymers.
a) Linear b) Cross link c) Branch
4. What would be the characteristics of a short oil paint?
Less than 45% oil to resin, more brittle with shoter overcoating period.
5. What would be the characteristics of a long oil paint?
More than 60% oil to resin, elastic and slower drying properties

9
6. What is meant by opaque pigment paint?
Inert particles with excellent light scattering properties inorder to give covering power and
color
7. What is the typical size of a pigment particle?
1/10th micron
8. Briefly describe the difference between “saturated” and “unsaturated” when referring to oil or
polymers.
Saturated oil or non-drying oil cannot be used as binder because it will not solidify by
polymerization to form a film. Unsaturated oil combined with oxygen to form a film.
9. Name two drying oils which are unsaturated.
a) Linseed oil b) Tung oil
10. What is the main difference between a dye and a pigment?
Dye dissolves while Pigment remains as solid particle in a vehicle.
11. What are the sources of a pigment?
a) Animals b) Mineral c) synthetically produced
12. If Titanium Dioxide was used in paint, what would be the color?
White
13. Name three rust inhibitive pigments considered to be toxic.
a) Red Lead b) Calcium Plumbate c) Coal Tar
14. Name four commonly occurring minerals used as extender pigments.
a) Clay b) Talcum c) Chalk d) Slate Flour
15. Name three laminar pigments.
a) MIO (Micaceous Iron Oxide b) Aluminium Flakes c) Glass Flake
16. If pigment was added way below the CPVC, how would it affect the film?
It would give a good gloss properties but poor covering power and with tendency to blister.
17. The abbreviation CPVC means what?
CPVC- Critical Pigment Volume Concentration
18. Why are thixotropes added to a paint formulation?
To keep solid particulate in a constituents in dispersion or to stop settlement.
19. If carbon was used as a pigment what would be the color?
Black
20. Name four properties that a binder contributes to a paint film.
a) Cohesive strength b) Ability to change from a liquid c) Ease of application
d) Adhesion to a substrate
21. Describe how a basic inhibitor works?
It is added as aids to manufacture, storage, application, film formation and film curing
22. Which of the common extenders could not be used in whites and pastels?
Clay
23. How would be the film affected if pigment was added above the CPVC?
The film would be porous, low in cohesive strength and adhesion.
24. Which of the rust inhibitive pigments is the most common?
Zinc Phosphate

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25. Why are extenders used in paint formulation?
To provide as fillers, adhesion, cohesion, film strength and durability.
26. If chromium was used as a pigment, what color would the paint be?
Greens, yellows and oranges
27. Why are plasticizers added to paint?
To give flexibility and reduces brittleness
28. Two metals are commonly used as galvanic paints, name them.
Zinc and aluminium
29. Why are driers added to oil based paints?
As Oxidants and to allow a thorough drying of the film
30. What is meant by the term thixotropic?
Thixothropic- the property of a certain jel of becoming liquid when stirred
31. What is meant by the term aggregate when referring to paint?
Agglomerates, a fine particulate solid e.g. pigments and extenders
32. If antioxidant was added to paint, what would it do?
Anti skinning, to retard the formation of skin on the surface of a paint.
33. Give the name of two plasticizers.
a) Alkyd Resin b) Non Drying oils (saturated oils)
34. What is meant by the term solution?
A resulting liquid
35. Give two example of a solution.
Salt and water.
36. What is meant by the term dispersion?
A solid or liquid dispersed within another liquid where there is no solubility.
37. There are two type of dispersion, what are they?
Suspension and Emulsion
38. If paint cures by chemical reaction, is it reversible or convertible?
Convertible and non reversible
39. What type of polymerization occurs in chemically curing paint?
Cross Linked polymerization
40. Name a paint which dries solely by solvent evaporation.
Chlorinated Rubber
41. What is meant by “non convertible”?
Allowing to go back into solution
42. What is meant by “non reversible”?
Could not be changed, could not go back into its original state.
43. Name four drying mechanism.
a) Solvent Evaporation b) Oxidation c) Chemical Curing d) Coalescence
44. In a coating, which dries by solvent evaporation, what type of polymerization occurs?
Linear Polymerization
45. What is another term of Fineness of Grind?
Aggregate Size

11
46. Which generic types of paint dry by solvent evaporation followed by oxidation?
Convertible or non-reversible paints or thermosetting
47. What type of polymer forms during oxidation?
Cross- linked polymers
48. What term applies to paint drying at ambient temperatures?
Air Drying
49. What is meant by the term coalescence?
To physically joined together
50. What is meant by the term Pot Life?
Period of time after mixing in which the paint must be used.
51. Name three curing agents used in epoxies.
Amides, amines and Isocynates
52. Is paint a solution or dispersion, qualify?
Dispersion, there is no solubility
53. What is an exothermic reaction?
Gives off heat
54. What is meant by the term induction period?
The length of time after mixing which the paint should stand before use.
55. What is the difference between thermoplastic and thermosetting?
Thermoplastic softens when heat is applied..Thermosetting cures with the application of
heat.
56. With a chemically curing paint, what type of polymerization occurs?
Cross Linking polymerization
57. Two other terms relates to induction period, what are they?
Stand time and lead time
58. Does a phenolic resin have an induction period?
No.
59. Which of the following binders are reversible?
a) Epoxy d) Urethane g) Cellulose
b) Phenolic e) Chlorinated Rubber h) Silicone
c) Vinyl f) Alkyd
60. Is epoxy powder paint thermoplastic or thermosetting?
Thermosetting
61. If a coating is permeable, what does it mean?
Ability to resist the passage of water
62. What is meant by cross linking, give two binders as an example?
Chemical curing. example-urethane and epoxy
63. What is the opposite of exothermic?
Endothermic
64. What is the term used in paints needing temperatures in excess of 650C to cure?
Stoving
65. What would be typical induction period for Chlorinated Rubber paint?
none

12
66. Name a material used as a dryer in paint formulation.
Napthanates of cobalt
67. Why would bentonite or wax be used in paint formulation?
To stop settlement
68. Name two materials used as plasticizers.
Castor Oil, Coconut oil
69. What generic type of paints would use anti-oxidants?
Oxidising Paints
70. How does a single pack epoxy ester paint dry?
By chemical curing..and uses moisture from the atmosphere to cure
71. How is Dew Point defined?
The temperature at which the water vapour in the air will condense.
72. How is Relative Humidity defined?
The amount of water vapour in the air expressed as a percentage of the water vapour which
could be in the air at the same temperature.
73. When using a Whirling hygrometer, which bulb should be read first and why?
Wet bulb
74. At what speed be used in wetting the wick on whirling hygrometer?
4m/sec.
75. What should be used when wetting the wick on whirling hygrometer?
Distilled water or clean rainwater
76. By what other name can we refer to a whirling hygrometer?
Aspirated Hygrometer or Psychrometer
77. When the air temperature rises does the air capacity to hold water increase or decrease?
Increases
78. What is the stated criterion for acceptance, prior to calculations, on a whirling hygrometer?
30 – 40 sec rotation
79. Name two pieces of equipment used for taking steel temperature.
Magnetic Limpet Gauge and Digital thermometer
80. Is it possible for a wet bulb temperature to be higher than the dry bulb?
No.

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PAINT TESTING

1. Define Viscosity.
Fluid’s resistance to flow
2. What is meant by high viscosity?
High resistance to flow; will not run easily
3. Approximately, what is the viscosity of water?
1 centi-poise
4. Name the cgs and SI units of dynamic viscosity.
Poise and dyne second per cm2
5. Name three different flow cups.
a) Zahn and Frikmar b) Ford c) ISO, DIN
6. When using a flow cup, which unit of viscosity would be used?
second
7. In a Ford Flow Cup No.4, what does “4” relate to?
4mm hole size
8. Give the names of three different rotational viscometers.
a) Rotathinner b) Krebs Stormer Viscometer c) Flow Viscometers
9. Give a reason for performing a viscosity test on site.
In order to determine the exact amount of thinner to be used at the point of application.
10. Which viscometer would not be used in thixotropic paint?
Flow Viscometer or flow cups
11. Why is temperature very important when doing viscosity test?
An increase in temperature (or decrease) has severe effects on fluids viscosity. As the
temperature increases, the molecules within a paint gain more molecules freedom, move
more easily and thus reduce viscosity.
12. What is the main difference between the rotathinner and Kreb Stomer?
Rotathinner uses circular disc with 4 holes holes drilled transversely through it while in Kreb
Stommer, the weight is allowed to fall, which in turn causes the paddle to rotate in the paint.
13. Give another name for A Fineness of Grind gauge.
Hegman Grind Gauge
14. Is a low flash point safer than a high flash point?
No
15. How and for what is a Hegman grind gauge used?
It is used to measure the degree of dispersion of paint. The paint samples are placed into the
top end of the gauge and drawn down using the scraper blade. Along the groove, at some
point, the aggregates will rest along the bottom and protrude through the surface. The
measurement can be made in microns where the coarse particles have been scraped out.
16. Briefly describe how to do the volatile, non volatile test to BS 3900 Pt B2.
-Select a clean, thoroughly dry glass and watch glass and weigh to the nearest milligrams.
-Place on to the watch glass approximately 2 gm of paint and weigh again.
-Place the watch glass with paint into a hot air oven, no naked flame or element; repeatedly
stir to drive away the volatile content.
-Take a final weight of the glass, rod and dry paint and simple calculation will give
volatile/non volatile ratio by weight.
17. Name the equipment used to determine the flash point of a solvent.
Abel Closed Cup
18. What color should the flame be at the flash point?
Blue
19. What formula is used to calculate the density?
14
 Density= weight
Volume
20. What formula is used to calculate specific gravity?
SG= Density of X
Density of Water
21. What is relative density?
Relative Density- the density of a substance relative to water.
22. What are the other names for a density cup?
Relative Density cup, Specific Gravity cup, weight per liter cup, weight per gallon cup,
pycnometer
23. What is a stoke, the unit for?
Stoke is a unit used to measure the kinematic viscosity
24. Which test is used to determine Abrasion Resistance?
Taber Rotary Abraser
25. Which equipment would be used to determine flexibility?
Conical Mandrel
26. Which equipment would be used to measure Impact Resistance?
Tubular Impact tester
27. For what reason would the Koenig Albert Apparatus to be used?
A pendulum with two spherical fulcra is free to swing on a plate painted with material under
test. The number of swing is counted electronically. If the fulcra penetrate the surface, more
resistance will reduce the number of swings
28. For which two reasons could a density cup be used on site?
a) Percentage of added solvent can be calculated b) If a 2 pack material has been in a
correct proportions
29. Name four accelerated test boxes.
a) Humidity Cabinet b) Salt Spray Cabinet c) Water Soak Test d) Temperature Cycling
30. Why would a tropical box be used?
For testing tropical condition where humidity is very high @ 95% and elevated temperature
up to 550C
31. Would a paint be higher or lower density than water?
Higher
32. How would the density be affected if a solvent was added to paint?
Lower
33. What is the capacity of density cup?
100 cc
34. What difference is there between SG and Density?
SG has no unit of value while Density has unit of value
35. What information could be obtained from a water soak test?
Water Absorption
36. What information could be obtained from temperature cycling test?
Expansion and Contraction related to cracking
37. What information could be obtained from a cold check test?
Contraction
38. Name four drying and curing test.
a) Ballotini test b) Beck Koller Stylus Test c) Mechanical Thumb Test d) Pencil Scratch Test
39. What stage of the BK test would be recorded as the drying time?
When no scratch is visible
40. Name three methods in determining opacity.
a) Cryptometer b) Hiding Power Chart c) Adjustable Film Applicator
15
41. What effects the opacity of a paint film?
The ability to hide (cover) the substrate.
42. Why would a Pfund cryptometer be used?
It determines the wet film opacity, a combined function of pigment concentration and
refractive index..
43. Give one reason why an inspector would use a PIG gauge.
The PIG test method is a destructive test to measure the thickness of a coating which is over
certain coating/substrate combinations and to also measure individual layers of a multi-layer
coating system.
44. Why are wet paint film thickness needed?
It gives added confidence that upon checking the following, the DFT should meet the
specification requirements.
45. Name two methods of measuring WFTs.
a) Eccentric Wheel b) Comb Gauge
46. What is the reason for taking WFT’s immediately after application?
In order to obtain a true reading. Solvent starts to evaporate away as it exits the spray tip.
47. Where could an inspector find information to determine if a 2 pack paint was mixed in the
correct proportions using a density cup?
Technical Date Sheet
48. Can a banana gauge be used on non-ferromagnetic substrate?
No
49. Could an eddy-current gauge be used on ferromagnetic substrates?
No.
50. Can a horseshoe gauge be used on non-ferromagnetic substrates?
No
51. As part of which test would a bar applicator be used?
Opacity
52. Which instruments would be used to measure reflectivity?
Gloss meter
53. How does a gloss meter works?
Gloss meter works on principle of light reflection.
54. Which factors in paint govern the degree of gloss?
a) PVC b) Degree of Dispersion c) Particle Size d) Resin Type e )Solvent type
55. In a primer/mid coat what would be the expected degree of grind?
Larger degree of grind to aid in cohesion and inter-coat adhesion
56. In a gloss paint, what would be a typical degree of grind?
Smallest degree of grind so that the aggregates will rest on the bottom.
57. What percent reading would be expected when measuring gloss on a glass panel?
100%
58. Using a gloss meter, a reading of 25% would signify what?
Low Gloss
59. If an aggregate size of 35 um was present in a paint of 30 um DFT, what would be a likely result
when using a gloss meter?
Gloss

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60. Name three common tests for determining adhesion of a paint film?
a) V-cut test b) Cross cut test c) Dolly Test
61. Which adhesion tests are quantitative?
Dolly Test
62. Inter coat adhesion and primer to substrate adhesion are two adhesion faults, name the third.
Cohesive Failure
63. What chemical solution is used to conduct a Cathodic Disbondment test?
3% of common salt solution
64. Which gas evolved at the cathode causes disbondment?
Hydrogen and Chlorine
65. What criteria are used when assessing a Cathodic Disbondment test panel?
The distance from the edge of the hole to the extent of disbondment should exceed the
stated requirements.
66. Name the two methods of applying Cathodic Protection.
a) Sacrificial Anode System b) Impressed Current System
67. What is used to determine the potential of a pipeline?
CP Monitoring using Half-cell electrode
68. Would it be advisable to refill a pipe trench with a carbonaceous backfill?
Yes
69. Does a Cathodic Protection System eliminate corrosion?
No, instead it protects against corrosion.
70. Can the external surface of a tank be protected?
No.
71. Could a crude oil tank be fully protected internally?
Yes up to the level of the medium
72. What voltage would be used on a 250 um thick coating with a sponge type pinhole detector?
9V
73. What voltage would be used on a 450 um thick coating with a sponge type pinhole detector?
90V
74. When using a wet sponge, what other liquid is added to the water?
Water with tiny amount of liquid detergent
75. What function does the above additive perform?
Provides a very low resistance circuit back to the control box
76. Would it be advisable to do wet sponge detection on galvanizing?
No.
77. Why work upwards on a vertical surface with a wet sponge?
To prevent tracks of water on the coated surface.
78. Does a sponge detector work on AC or DC current?
DC current
79. Other than the wet sponge, which other equipment could be used to determine the presence of
pinholes/holidays?
High Voltage DC Holiday Detector

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REVISED QUESTION (GENERAL)

1. Name two categories of paint mill.

a) Pre-mixing b) Dispersion or grinding or milling
2. What is the main reason for processing paint in a mill?
Where the remaining amount of binders/solvent and any other additives are finally and
thoroughly mixed prior to quality check and canning.
3. Briefly describe how ball mill works.
A ball mill is a horizontal steel drums which is approximately half filled with various types of
balls. Mill base is added to the drum until the ball are covered about 50% of the capacity. The
hatch is then sealed off and the drums started rotating at such a speed so that the balls
cascades down and do not stick on the drum due centrifugal forces. Shear forces are applied
to the mill base. A typical dispersion time would be overnight and not the preferred system
for paint making due to the time taken.
4. Briefly describe how attritor mill works.
The Attritor mill is a vertical version of ball mill, but more efficient and static. The ball are
driven by paddles. The mill base is continually circulated by pump from bottom to top and
gives dispersion in less time.
5. When would steel balls not to be used in a ball mill?
When the dispersion time starts
6. A bead mill is sometimes called by which other names?
Sand Mill or Pearl Mill
7. How does a colloid mill works?
Uses stone grinding disc containing carborandum approximately 10” in diameter. The top
stone is stationary and the lower stone is rotating is rotating fast at speed up to 3600 rpm.
Gravity fed low viscosity slurry enters the center of the static top stone and is passed between
the two stones by centrifugal force, where it is subjected to extreme turbulence and shear
forces to affect the dispersion.
8. Name eight items of information listed on materials data sheet.
a) Description
b) Recommended Use
c) Service Temperature
d) Certificates/Approvals
e) Availability
f) Physical Constants
g) Application Details
h) Safety
9. What do you understand from the term halogenated hydrocarbons?
One of a group of halogen derivative of organic hydrogen and carbon containing compounds.
10. How can we determine the viscosity of high viscosity paint?
By Rotational viscometer

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11. Briefly describe the principle of CP.
Employs the bi-metallic principles by using the less noble metal as pigmentation. This is by
making the metal a cathode by means of impressed current or attachment to a sacrificial
anode
12. What function does the primer have in a paint system?
It provides adhesion to a substrate and also provides a key for any subsequent layer
13. In a mordant primer, what is the main working constituent?
For etching new galvanizing
14. What advantages do electrostatic application methods provide?
Both liquid and powder paints can be applied.
15. What is the most expensive type of brush filling?
Synthetic type
16. What is cohesive failure in paint, give the main cause?
Failure within paint film. Solvent Entrapment
17. Why does a zinc rich paint need a strong binder?
In order to hold the high concentration of zinc particles together.
18. Why are etch primers not spray applied?
Because of its acid content
19. What do you understand by the term overspray?
A deposit of wet or dry coating particles.
20. Name four methods of determining DFTs.
a) Test Panel b) Calculation c) by destructive test gauge d) non destructive gauge
21. What is psychrometer used for?
It is used for determing the wet and dry bulb temperature readings.
22. What color should a galvanized surface be after application of T-wash?
Matt Yellow with an underlying black or darkened substrate
23. How soon can a T washed substrate be coated?
16 hrs
24. Other than pigment, base and curing agent, name two other constituents of FBE powder paint.
a) Fillers b) Extenders
25. Give the main differences between airless and conventional spray.
Air is not used for atomization for airless spray while in conventional spray, air is used for
atomization.
26. Brush application has advantage over spray application, what are they?
a) More environmentally friendly results in less waste of materials b) virtually no spotting
or overspray damage to adjacent areas.
27. What is the main consideration when selecting a metallic pigment for a sacrificial paint?
Potential requirements.
28. What is meant by sherardizing?
It is a method of galvanizing wherein an airtight container is heated containing a powdered
zinc just below its melting point.
29. Name three types of paint feed for a conventional spray.
a) Suction feed b) Gravity Feed c) Remote Pressure Pot

19
30. What is the calorising process?
Calorising is coating with aluminium.
31. Why would a sealer be applied to Aluminium metal spray?
To give an extended major maintenance free life
32. What is the BS 2015 term for skipped or missed areas?
Misses/Skips
33. A color has three properties, what are they?
a) Hue b) Brightness c) Saturation
34. Why would paint be applied by hot spray?
When paint is heated, it reduces the viscosity and the cure or drying starts quicker. It is
therefore easier to apply and wets out better, and reduces the need for solvent addition.
35. On an airless spray tip, how are blockages cleared?
Blockages can be cleared by turning the tip through 180 o, triggering to ground or a container
to clear the blockage, then reverse again the tip to its original position.
36. How atomization is achieved using conventional spray?
At the gun when the trigger is operated, a tapered needle is drawn back opening the aperture
out of which the paint exits in a continual stream. Approximatelt 25 mm in front of the
aperture, two air channel from lugs of the cap, diametrically opposed blow air to converge at
the paint stream. At this convergence, the paint is atomized into very minute droplets and
conducted onto the workplace.
37. How atomization is achieved using airless spray?
With the Airless spray, the fluid (paint) is pressurized by means of pump operated by
compressed air. These units operate by the increasing the compressed air inlet pressure using
two pistons on a common shaft at a stated ratio. Atomization occurs by forcing the paint at
extremely high pressure usually at 2000 to 2500 psi through a very small aperture, 12 to 23
thou diameter, into a volume of air offering a resistance to the paint flow. As the paint and air
meet, the paint atomizes.
38. What is dip coating?
A component is dip into paint and hung to dry.
39. What do you understand from the term ropiness?
Brush Marks that have not flowed out because of the poor leveling properties of the coating
materials
40. What is efflorescence and how does it occur?
A whitish crystalline formation caused by soluble salts crystallizing on the surface.
41. Name two ways of melting aluminum to enable it to be sprayed.
a) Powder system b) Electric Arc system
42. What is flocculation?
The development of loosely cohesive pigments agglomerates in a coating material
43. What would be the causes of bitiness in a paint film?
The presence of particles of a gel, flocculated material or foreign matter in a coating material
projecting from the surface of the film.
44. What is a tie coat?
A coat between two different types of coating.

20
45. How many depressions of the bellows are needed for the dragger test?
5
46. What are the hazard signs for Toxic, Very Toxic, harmful and corrosive?
Black symbol of skull and crossbones
47. What is saponification.
The formation of soap by the reaction of a fatty acid ester and an alkali
48. What units are used to measure toxicity?
ppm
49. Which material would have to be used on a perpetually damp surfaces?
Single Pack moisture curing polyurethane
50. What is padding?
Mainly DIY . Pads of Mohair or foam are used to apply paint
51. What air inlet pressure is needed to give 2500 psi delivery with 35:1 pump?
3500 psi
52. What causes lifting of a paint film?
Caused by solvent strength and lack of observance of over coating time
53. What is cissing and how it is caused?
Formation of small areas of wet film of coating material where the coating matl has receded
leaving holidays in the film. It is caused by inadequate surface preparation
54. What is meant by abbreviations: OES, OEL, MEL, UEL, LEL and RAQ?
OES-Occupational Exposure Standard
OEL- Occupational Exposure Limit
MEL- Maximum Exposure Limit
UEL-
LEL-
RAQ-
55. Why should a paint inspector use potassium hexacyonoferrate?
To detect the presence of either sulphates or chlorides
56. What would be an average thickness for galvanizing?
100 um
57. How can you tell the difference between blooming and chalking.
A deposit resembling the bloom on a grape for blooming while in chalking the formation of
friable and powdery layer on the surface of the film
58. What could be the reasons for inter coat adhesive failure?
Lack of observance of recommended over coating limits and expansion/contraction difference
between materials. Failure between film
59. How would you determine quantity of added thinners in thixotropic paint?
By rotational viscometer
60. Why are manufacturers developing solvent free, water borne and powders?
Due to COSHH Regulations and EPA requirements.
61. What would be the cause of grinning on a paint film?
Due to inadequate hiding power of the coating material

21
62. How can “bleeding” be avoided?
By applying two coats of sealer in which the bleeding coat is insoluble
63. In less than 30 words, explain the duties of a paint inspector.
Painting Inspector is responsible for verifying that the coating works performed is in
accordance with the job specifications, approved procedures and other relevant contract
documents.
64. Name five documents which a painting inspector need on a contract.
a) Job specification b) Data Sheets for paints/coatings c) Procedures d) Quality Plans
e) Plant/Project Drawings
65. What information should be given on a daily report sheet?
a) Details of the Contract and Contractor
b) Ambient conditions applicable during the work period
c) Information required for surface preparation activities such as methods used, original
substrate condition, abrasive type, degree of cleanliness achieved, profile achieved,
identity of plant and time of starting and completion
d) Information required for materials used and painting application activities
e) Comment
66. Curtains, Sags, Runs and Tears are result of what?
Application related coating faults
67. Some binders can be modified to use water as solvent, name four.
a) Alkyds
b) Epoxies
c) Polyesters
d) Polyurethane
68. What is meant by the term stripe coat?
Stripe Coat is a coat of paint applied only to edges or welds of steel structure before full coat.
69. How many cc in 4.5 liters?
4,500 cc
70. A paint data sheet provides a wealth of information, name eight items.
a) Description
b) Recommended Use
c) Service Temperature
d) Certificates/Approvals
e) Availability
f) Physical Constants
g) Application Details
h) Safety

22
PA 10 SPECIFICS

1. What is the specified course of action in the grit inclusion?

Re-prepare the affected areas and re-apply the complete painting system.
2. The term “long term protection” refers to what?
Protection typically last for 10 years.
3. What is the difference between new and weathered galvanizing?
New galvanizing- a galvanized steel surface on which a cohesive oxide has not yet formed
Fully galvanizing- a galvanized steel surface on which cohesive layer has formed by natural
weathering.
4. What criterion determines which paint system should be used?
Design consideration
5. What is the total DFT of the compliant epoxy system?
265 um
6. What is the total DFT of the water borne system?
225 um
7. When can ladders and other means of access be removed?
Until approval has been given by the Engineer
8. Two materials are specified for used on a damp surfaces, what are they?
a) Moisture curing polyurethane
b) High Solid Multi-component Epoxy Paints
9. After removal of a non-drying paint, which type of primer is recommended?
White Spirit- based primer
10. Some ferrous substrates are painted for aesthetic only, name four.
a) Pre-painted Cladding
b) Glass Reinforced Plastic
c) Concrete
d) Multi-component Liquid
11. Which three non-ferrous substrates are painted for anti corrosion purposes?
a) New galvanized surfaces
b) Weathered galvanized surfaces
c) Aluminium surfaces
12. According to PA10 in which situations would “T” wash be used?
When sweep abrasive blast/hand abrading is impractical for new galvanizing.
13. How many coats of primer are specified on surfaces at 100-149oC?
2 coats
14. Give preferential order of coating system for surfaces 150-340oC?
a) Thermal Spray Aluminum b) Inorganic Zinc Silicate c) Polysiloxane Inorganic Coating
15. Is it mandatory for a contractor for a test area?
No
16. List four items needing masking off prior to blasting and painting?
a) Fire Protection Equipment
b) Weld End Preparation
c) Atmosphere sensing heads
d) Vents on control equipment
e) Name plates
17. Which Aluminum substrate would not be sweep blasted?
Thin Gauge Aluminium Substrate

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18. Which three paint system are specified for use on Aluminum?
a) Water Borne Acrylic
b) Epoxy High Build
c) Alkyd or Modified Alkyd
19. What differences are there in new and maintenance painting specifications for substrates below
100oC?
a) Requirements of SPA1a to SPA1c shall apply to New painting specification for substrate
below 100 deg. C.
b) Requirements of SPA1d shall apply to maintenance painting for substrate below 1000C.
20. Toxic coating need special considerations for removal from substrates, name two methods
which comply.
a) Must be properly disposed in accordance of EPA 1991
b) Must be in accordance with Water Act 1991
21. In which situations is a Permit to Work required?
Site Safety Requirements
22. Which primers are specified for non-weathered galvanizing?
-MIO
-Pigmented high build epoxy
- Alkyd or Modified alkyd
23. Which primers are specified for weathered galvanizing?
- MIO
-Pigmented high build epoxy
- Alkyd or Modified alkyd
24. According to PA 10, is flame cleaning allowed?
No
25. According to PA 10, is thinning of paint allowed?
Yes
26. What temperature range is covered by hot duty service?
27. Does PA 10 cover internal coatings on pipes?
No.
28. What is the specified overlap on repair areas?
100mm
29. What would be the specified surface preparation and coating system for Aluminum Cladding?
Sweep abrasive blast/hand abrading
30. What would be the procedure for removal of algae and mould?
All algae and mould should be treated with biocidal agent and left a minimum of 24 hrs. It
should then be removed by scrubbing with stiff bristle brushes and clean water or by use of
high pressure water washing.
31. What would be the procedure for degreasing prior to surface preparation?
It must be removed by washing with an appropriate solvent
32. What would be the procedure for degreasing after to surface preparation?
It must be removed by surface washed with clean water and thoroughly dried
33. When blast cleaning on an AGI, what precautions are to be taken?
Safety requirements associated with blast cleaning must comply with current regulations.
34. Is it permissible to prepare paint by stirring?
Stirring is permissible for 5 liter-container or less
35. What would be the surface preparation method for new galvanizing?
Sweep Abrasive Blast

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36. When would it be necessary to apply a sealer to inorganic zinc silicate?
When the service temperature is above 340oC
37. How could areas of a paint breakdown be prepared for repainting?
Re-surface prepared the affected areas
38. What information should be on a paint label for BG?
Grade is specified and labeled in accordance with PA9
39. When measuring DFT over galvanizing, what allowances are made?
Minimum thickness of the full paint system should be 120 um plus MIO Build Coat
40. What is the first coat applied to galvanized substrates and why?
One coat of MIO Build Coat (65um). This is to protect the underlying from attack and
subsequent degradation.
41. What are the considerations when selecting a paint system?
a) Each painting job is unique, and therefore it is essential to be selective and to specify
unequivocally.
b) Cost of Painting
42. Properties and Performances of Paint are covered in which BG specification?
PA9
43. According to PA 10, which two coats are applied at works?
Heat Resistant Aluminum pigmented Epoxy or Urethane primer
44. Give the criterion for when and when not, painting can take place.
Painting cannot take place:
-When the air or metal temperature is down to within 3 degrees C above the dew point
-When the air or metal is below 5 degrees C
-When the Relative Humidity is above 90%
45. What should be the substrate reaction when “T” wash is applied to a newly galvanized
substrate?
When dry, a matt yellow translucent film, with underlying black or darkened substrate
46. Which two materials are specified for use on damp surfaces?
Moisture curing polyurethane and High Solid multi-component epoxy
47. What is the maximum time lapse from surface preparation to coating?
4 hrs
48. Which is the most common pigment in high temperature paints?
Aluminium Silicate
49. What would be the result of over thick application of zinc silicate?
Brittlement
50. According to PA 10, is roller application permissible?
No

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