Surface Preparation for Various Substrates 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 Surface Preparation for Various Substrates flashcards as text
When preparing a previously painted concrete floor that shows efflorescence, what is the correct treatment before applying a new coating?
Answer: Neutralize with a dilute acid wash and rinse thoroughly
Efflorescence (salt deposits) on concrete must be removed with a dilute acid wash (such as muriatic acid) and thoroughly rinsed before any coating is applied.
A painting contractor is prepping galvanized metal that has never been painted. Which primer type is most appropriate for this substrate?
Answer: Zinc-rich self-etching primer
New galvanized metal requires a zinc-rich or self-etching primer to promote adhesion, as its zinc coating resists bonding with conventional primers.
What minimum ambient temperature is generally recommended when applying water-based (latex) coatings to exterior wood substrates?
Answer: 50°F (10°C)
Most latex coatings require a minimum ambient and surface temperature of 50°F (10°C) for proper film formation and adhesion.
When pressure washing a wood substrate prior to painting, what is the recommended drying time before applying paint in typical California conditions?
Answer: 24–48 hours
Wood should be allowed to dry at least 24–48 hours after pressure washing to ensure moisture content is low enough for paint adhesion.
A contractor encounters a stucco surface with existing alligator cracking. What is the correct preparatory step?
Answer: Grind out cracks, fill with appropriate patching compound, and allow to cure
Alligator cracks in stucco must be ground out and filled with a compatible patching compound before any coating is applied to ensure a stable substrate.
Which condition on a steel substrate requires immediate attention before blast cleaning to avoid creating a hazardous situation?
Answer: Oil or grease contamination
Oil or grease must be removed by solvent cleaning before blast cleaning, as abrasive blasting drives contaminants into the surface rather than removing them.
When preparing interior drywall in new construction for a flat latex finish, what surface profile is typically required?
Answer: A smooth, well-primed surface free of tool marks and imperfections
Interior drywall for flat latex finishes requires a smooth, primed surface free of defects, tool marks, and fastener pops so that the finish coat lies uniformly.