Which action should be performed to prepare the surface before applying color coats?

• A. Apply a sealer over the old finish
• B. Polish the surface to a high gloss
• C. Roughen with heavy sanding and leave
• D. Apply wax

Answer: (A)

Before applying color coats, you need a uniform, clean base that the paint can bond to. Applying a sealer over the old finish does exactly that: it blocks any residual pigments or contaminants from bleeding through, creates a consistent surface texture, and improves adhesion for the color coats. This gives the color a smooth, even appearance and reduces the risk of peeling or uneven gloss later on.

Polishing to a high gloss would leave oils, waxes, or polishing compounds on the surface, which can prevent the new paint from sticking properly. Roughening heavily and leaving it there would create an uneven, damaged substrate that still isn’t ready for color and could require more steps. Applying wax also forms a barrier that repels paint, preventing proper adhesion.