Answer
For PVC trim boards, scuff lightly with 220 or 320, then refine with 400.
Why it happens
PVC trim needs light scuffing, not aggressive wood-style sanding.
Recommended grit
Use 220 or 320 for scuffing, then 400 for smoother paint prep.
Wet or dry
Dry.
Success check
The trim is clean, dull, and free of deep scratches.
What to do
- Clean the PVC trim board.
- Scuff lightly with 220 or 320.
- Refine visible areas with 400.
- Remove dust before primer or paint.
Avoid: Do not sand PVC trim like rough wood.