Surface PreparationQuestion 23 of 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
Explanation
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.
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