C33 Identifying and Remedying Paint Failures and Defects 4

Question 1

A painted wood surface shows a condition where the paint film has split along the wood grain lines. What is this defect called?

Accepted Answer

Checking

Answer

Checking is the splitting of the paint film along or across wood grain, typically caused by overly thick paint or inadequate flexibility of the coating.

Question 2

Which condition describes a paint failure where new paint peels away from the previous coat but both remain bonded to the substrate?

Accepted Answer

Intercoat adhesion failure

Answer

Intercoat adhesion failure occurs when insufficient surface preparation, incompatible products, or insufficient dry time causes the new coat to separate from the previous coat.

Question 3

A homeowner notices a dark, fuzzy growth appearing through a freshly painted bathroom wall. What is the most likely cause?

Accepted Answer

Mold or mildew growth from moisture not fully remediated before painting

Answer

Painting over active or inadequately treated mold without proper remediation allows growth to continue and penetrate through the new paint film.

Question 4

When painting over a glossy surface without sanding or etching, which failure mode is most likely to occur?

Accepted Answer

Poor adhesion leading to peeling

Answer

Glossy surfaces offer insufficient mechanical or chemical bonding sites, so the new coat fails to adhere and eventually peels.

Question 5

What paint defect results from applying a solvent-based topcoat over a water-based primer that has not fully cured?

Accepted Answer

Lifting or wrinkling of the topcoat

Answer

The solvents in the topcoat soften the uncured primer beneath, causing the topcoat to wrinkle or lift as trapped solvents escape.

C33 - C-33 California Painting Contractor License Practice Test

C33 - C-33 California Painting Contractor License Practice Test

C33 Identifying and Remedying Paint Failures and Defects 4