C33 Identifying and Remedying Paint Failures and Defects 5

Question 1

What causes 'picture framing' when rolling paint onto a wall?

Accepted Answer

Failure to back-roll or blend the brushed edges while the paint is still wet

Answer

Picture framing occurs when brush-cut edges dry before being blended with the roller, leaving a visible border around the painted area.

Question 2

A contractor notices that an oil-based paint applied to a metal door has developed a network of fine cracks resembling crazing glass. What is the most likely cause?

Accepted Answer

The topcoat was applied too thick and dried faster on the surface than below

Answer

When a heavy coat skins over rapidly on the outside while the interior is still wet, differential shrinkage creates a crazing or cracking pattern.

Question 3

Which type of stain is most likely responsible for yellowish-brown water marks that bleed through multiple coats of white interior paint?

Accepted Answer

Water-soluble extractives wicking from a water-damaged substrate

Answer

Water damage can activate soluble extractives in drywall paper, wood, or plaster that wick to the surface and bleed through standard paint.

Question 4

What is the primary reason paint applied in direct, hot afternoon sun on an exterior surface is prone to failure?

Accepted Answer

The surface is too hot, causing the solvent to flash off before proper film formation

Answer

When a surface is very hot, solvents or water evaporate too quickly, preventing the paint molecules from properly coalescing into a continuous film.

Question 5

A C-33 contractor is asked to repaint a surface showing heavy chalk. Before repainting, what is the proper remediation step?

Accepted Answer

Pressure wash or scrub off all chalk residue and allow to dry before priming

Answer

Chalk must be removed because it acts as a release layer; painting over it results in poor adhesion and eventual peeling of the new coat.

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 5