ANSWER ALL QUESTIONS IN THIS SECTION
QUESTION 1
What type of defects does wicking cause if each glass fibre is not completely
wetted out? - ANSWERS-*Underfilm corrosion
*Blistering
*Delamination
QUESTION 2
Where are moisture cured urethane used? - ANSWERS-In areas of high humidity,
where other materials generally cannot be used.
QUESTION 3
Explain what moisture cured urethane are? - ANSWERS-Frequently single
package materials that must be applied in strict accordance with the owner's and
manufacturer's requirements.
QUESTION 4
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, NACE CIP LEVEL 2 LATEST
What are the common failure modes of Moisture-cured Urethane? - ANSWERS-
*failure to cure if used in low humidity environment
*Blistering and delamination if surface not prepped as per the specification
QUESTION 5
What are Two-component Thin Film urethane coatings? - ANSWERS-These are
mostly used as topcoats over epoxies due to their good-to-excellent UV resistance
and their wide availability in different colours.
QUESTION 6
Common failures of Tow-Component thin film urethane coatings are? -
ANSWERS-*Delamination-due to application after overcoat window
*Color & gloss differences from using different batches or techniques in the
application.
*Blushing-from moisture on the surface during the cure
*Failure to cure- happens if thinner used contains any moisture
QUESTION 7
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, NACE CIP LEVEL 2 LATEST
Inspection criteria for Two-component Thin Film urethane coatings is? -
ANSWERS-*Use required standard inspection
*Watch the DFT closely
*If thinner used, ensure that coating supplier approves of this in writing
QUESTION 8
Thick film Polyurethane, Polyureas and their hybrids are products applied by? -
ANSWERS-Applied by heated plural airless spray
QUESTION 9
What must inspectors be aware of with Thick film Polyurethane, Polyureas and
their hybrids? - ANSWERS-*They have a very short pot life, sometimes a short as
9 seconds
*Understanding that even though grouped as a single family, the individual
products often have very different use and application characteristics
*Must understand how the specialized spray equipment works and
*Understand the unique mixing at the tip of the gun
QUESTION 10
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, NACE CIP LEVEL 2 LATEST
What are the common failure modes of Thick film Polyurethane, Polyureas and
their hybrids? - ANSWERS-*Delamination- caused by am improper specification.
*Failure to cure- caused by failure of the equipment to heat or pump proper
amounts of each material to the gun or issues at the gun tip.
QUESTION 11
What would Thick film Polyurethane, Polyureas and their hybrids limitations for
application be? - ANSWERS-*Polyurea's are normally applied over an epoxy
primer when used on steel, but not required when applied over concrete
*Polyurethanes and some Polyurea hybrids are commonly applied directly to steel,
but they sometimes require an epoxy primer on concrete.
QUESTION 12
How do Siloxanes come and what are they normally blended with? - ANSWERS-
Siloxanes come as single-packaged or two-component materials and are normally
blended with other resins such as acrylic, epoxy or polyurethane
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