Answer
Clean first, then scuff with 220. Use 320 or 400 for finer prep.
Why it happens
New paint usually needs a clean, dull, lightly abraded surface for prep.
Recommended grit
Use 220 for general scuffing; use 320 or 400 for finer prep.
Wet or dry
Dry for general prep.
Success check
The surface is evenly dull and clean.
What to do
- Clean the glossy surface first.
- Scuff evenly with 220 grit.
- Use 320 or 400 for lighter fine prep.
- Remove dust before repainting.
Avoid: Do not repaint over a dusty or glossy unprepared surface.