Finish TradesCâu 217 / 700
A painter must achieve a specified DRY film thickness. During application the coating is checked with a wet-film gauge. Why is the WET film reading higher than the target dry film thickness?
a.Because the gauge is inaccurate on wet paint
b.Because solvent or water evaporates as the coating cures, leaving a thinner dry film
c.Because dry film always equals twice the wet film
d.Because primer adds thickness after topcoating
Giải thích
A coating shrinks as its solvent or water evaporates, so the dry film is thinner than the wet film. Knowing the percent solids lets the painter target a wet film that cures down to the specified dry thickness. The gauge is accurate, dry film is not double wet film, and primer does not increase topcoat thickness.
Luyện miễn phí toàn bộ 700 câu hỏi — không cần đăng ký.
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