Answer
For primer sealer before paint, sand lightly with 400 or 600 after it cures, then clean before topcoat.
Why it happens
Dust nibs or texture in primer sealer need light smoothing before topcoat.
Recommended grit
Use 400 or 600 lightly before paint.
Wet or dry
Dry or wet depending on coating instructions.
Success check
The primer sealer feels smooth and is ready for paint.
What to do
- Let primer sealer cure as directed.
- Sand lightly with 400 or 600.
- Avoid cutting through edges.
- Clean the surface before topcoat.
Avoid: Do not sand through primer sealer to bare material.