PCS Coating Application Techniques 4

Question 1

Before coating application, the steel surface temperature must be at least how far above the dew point, per common industry practice?

Accepted Answer

5°F (3°C)

Answer

Industry practice and most specifications require the surface to be at least 5°F (3°C) above the dew point to avoid condensation.

Question 2

An inorganic zinc-rich primer is applied too thick. Which defect is most likely?

Accepted Answer

Mud cracking

Answer

Inorganic zinc silicates are prone to mud cracking when applied above the maximum recommended DFT.

Question 3

Why must zinc-rich primers be agitated continuously during application?

Accepted Answer

To keep heavy zinc dust in suspension so that the zinc loading stays uniform

Answer

Zinc dust is dense and settles quickly, so continuous agitation keeps the zinc content in the applied film consistent.

Question 4

A freshly applied amine-cured epoxy shows a greasy, waxy surface film after curing in cool, humid conditions. What is this defect, and what is the typical remedy before recoating?

Accepted Answer

Amine blush; wash with clean water and detergent, then rinse

Answer

Amine blush is a water-soluble carbamate that must be removed by washing before recoating to avoid intercoat adhesion failure.

Question 5

What is a key reason for applying a coat after the minimum recoat time but before the maximum recoat window ends?

Accepted Answer

To ensure good intercoat adhesion without having to abrade the surface

Answer

Recoating inside the window allows chemical or mechanical bonding between coats, while going past it often requires abrading or a tie coat.

PCS - Protective Coatings Specialist Certification Practice Test

PCS - Protective Coatings Specialist Certification Practice Test

PCS Coating Application Techniques 4