Before primers and finish coats may be applied to a metal surface, the surface must be properly prepared. What statement is true concerning surface preparation?

Correct Answer: Option C — All dirt, oil, grease, rust, mill scale, and loose paint must be removed.

Proper surface preparation is critical for paint adhesion and corrosion prevention. All contaminants, including oil, grease, rust, mill scale, and loose paint, must be removed to ensure the primer bonds directly to the substrate. Failure to remove these items will result in premature coating failure and continued corrosion.