FREE C33 Identifying and Remedying Paint Failures and Defects Questions and Answers

Question 1

A painted surface shows a pattern of deep, interconnected cracks resembling crocodile skin. What is this defect called and what is the most likely cause?

Accepted Answer

Alligatoring, caused by applying a topcoat over an uncured primer.

Answer

Chalking, caused by UV exposure.

Answer

Blistering, caused by moisture trapped beneath the paint.

Answer

Efflorescence, caused by salts leaching from masonry.

Question 2

When painting a concrete block wall, you notice white, powdery salt deposits on the surface. What is the first step to properly remedy this issue before priming?

Accepted Answer

Remove the deposits with a wire brush and rinse the surface.

Answer

Apply an oil-based primer directly over the deposits.

Answer

Pressure wash with a chemical stripper.

Answer

Sand the surface with 80-grit sandpaper.

Question 3

Paint is peeling in large sheets from a previously glossy interior wall. What is the most probable cause of this failure?

Accepted Answer

The previous glossy surface was not sanded or de-glossed.

Answer

The wrong type of roller was used.

Answer

The paint was applied in low humidity.

Answer

The paint was thinned too much before application.

Question 4

A freshly painted surface develops a rough, wrinkled appearance shortly after application. This defect is known as wrinkling. What is a common cause?

Accepted Answer

Applying the paint too thickly.

Answer

Using a primer from a different manufacturer.

Answer

Painting over a surface that is too cold.

Answer

Not stirring the paint enough before use.

Question 5

What is the primary cause of blistering in an exterior paint job?

Accepted Answer

Moisture trapped under the paint film.

Answer

Excessive chalking of the previous coat.

Answer

Using a low-quality paint brush.

Answer

Applying paint in high humidity.

Question 6

After washing an old, painted exterior wall, you wipe your hand across it and a powdery residue comes off. To ensure proper adhesion of the new topcoat, you should:

Accepted Answer

Rinse thoroughly, allow to dry, and apply a chalk-sealing primer.

Answer

Paint directly over the chalky surface with a high-quality latex paint.

Answer

Apply two coats of finish paint instead of one.

Answer

Lightly sand the surface and then apply the finish coat.