What grit sandpaper is used for final sanding before primer?

• A. 180-320 grit
• B. 40-60 grit
• C. 400-600 grit
• D. 800 grit

Answer: (A)

Sanding texture is what primes need to grip. For the final prep before primer, you want a surface that’s smooth enough to look good but still has some tooth for the primer to grab onto. A mid-range grit in the 180–320 range hits that balance well: it can level and feather the repaired area without creating deep scratches, while leaving enough texture for the primer to bond to.

Using finer grits like 400–600 would leave the surface too smooth for optimal adhesion, making it harder for the primer to bite in. Coarser grits such as 40–60 would leave noticeable gouges that require more filler work to hide. An 800-grit finish is typically too fine for the final pre-primer step and is more common for very light sanding or between primer coats after adhesion and curing.