Answer
Between cured polyurethane coats, scuff lightly with 320 or 400 and remove all dust.
Why it happens
Light scuff sanding helps level dust nibs and gives the next coat a clean surface.
Recommended grit
Use 320 or 400 between cured polyurethane coats.
Wet or dry
Dry; wet only when the finish instructions allow it.
Success check
The coat feels smooth and dull without sanding through the finish.
What to do
- Let the polyurethane cure as directed.
- Scuff lightly with 320 or 400.
- Avoid sanding through edges.
- Remove dust completely before the next coat.
Avoid: Do not sand uncured polyurethane.