Identifying and Remedying Paint Failures and Defects Flashcards
7 cards from real C33 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Identifying and Remedying Paint Failures and Defects flashcards as text
What causes 'picture framing' when rolling paint onto a wall?
Answer: Failure to back-roll or blend the brushed edges while the paint is still wet
Picture framing occurs when brush-cut edges dry before being blended with the roller, leaving a visible border around the painted area.
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?
Answer: The topcoat was applied too thick and dried faster on the surface than below
When a heavy coat skins over rapidly on the outside while the interior is still wet, differential shrinkage creates a crazing or cracking pattern.
Which type of stain is most likely responsible for yellowish-brown water marks that bleed through multiple coats of white interior paint?
Answer: Water-soluble extractives wicking from a water-damaged substrate
Water damage can activate soluble extractives in drywall paper, wood, or plaster that wick to the surface and bleed through standard paint.
What is the primary reason paint applied in direct, hot afternoon sun on an exterior surface is prone to failure?
Answer: The surface is too hot, causing the solvent to flash off before proper film formation
When a surface is very hot, solvents or water evaporate too quickly, preventing the paint molecules from properly coalescing into a continuous film.
A C-33 contractor is asked to repaint a surface showing heavy chalk. Before repainting, what is the proper remediation step?
Answer: Pressure wash or scrub off all chalk residue and allow to dry before priming
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.
Which paint defect is characterized by small, dome-shaped bumps on the paint film caused by trapped moisture or solvent vapor?
Answer: Blistering
Blistering forms when moisture or solvent vapor pressure beneath the paint film pushes the film outward, creating bubbles or domes.
On a repaint project, the new exterior paint is showing 'lap marks' or 'holidays' where roller passes overlap. What is the most effective preventive measure?
Answer: Maintain a wet edge by working in manageable sections and blending overlaps before the paint dries
Lap marks appear when a dried edge is painted over; maintaining a wet edge by working section by section and overlapping into wet paint eliminates visible lines.