What must be removed from wood surfaces immediately after sanding and before applying a finish?

• A. All dust, dirt, and grease must be completely removed.
• B. Only large debris, leaving fine dust.
• C. Water and solvents only.
• D. Nothing needs to be removed.

Answer: (A)

After sanding, the surface must be cleaned completely before finishing. All dust, dirt, and grease should be removed because sanding creates fine wood dust that can clog pores and trap under the finish, causing adhesion problems or a cloudy, uneven film. Oils or grease on the surface, from hands or previous cleaners, will repel the finish and prevent a solid bond. The right approach is to vacuum or brush away the dust, wipe with a tack cloth or a damp, lint-free cloth, and, if needed, use an appropriate solvent to remove oils, then ensure the surface is completely dry before applying the finish. Leaving behind dust or grease would lead to poor adhesion and finish defects.