Surface PreparationCâu 23 / 100
Why is it important that a masonry surface be fully cured before painting with most coatings?
a.Fresh masonry is highly alkaline and can chemically attack (saponify) some paints
b.Cured masonry cannot hold paint
c.Fresh masonry is too smooth to paint
d.Curing changes the color of the paint
Giải thích
New concrete and masonry are strongly alkaline while curing, and this alkalinity can break down oil-based coatings, a reaction called saponification. Allowing the masonry to cure (often about 28 days) and/or using an alkali-resistant primer prevents coating failure. Testing surface pH can confirm readiness.
Luyện miễn phí toàn bộ 100 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- Why should exterior wood be checked for moisture content before painting?
- What is 'feathering' when preparing a spot repair on a painted surface?
- When dry-cutting or grinding concrete during prep generates dust, what airborne hazard is of concern under Cal/OSHA?
- Before applying an elastomeric coating to a stucco crack, what prep step is typically needed?
- A previously painted surface shows widespread peeling down to bare wood. What does this MOST likely indicate?
- What is the correct order of the basic surface-prep steps for a typical repaint?
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