Answer
For melamine, clean first, then scuff lightly with 220 and finish prep with 320.
Why it happens
Melamine has a hard slick surface that needs light scuff sanding after cleaning.
Recommended grit
Use 220 for scuffing and 320 for smoother primer prep.
Wet or dry
Dry.
Success check
The surface is clean, dull, and ready for bonding primer.
What to do
- Degrease the melamine surface.
- Sand lightly with 220 grit until the gloss is dulled.
- Use 320 grit for a smoother prep finish.
- Wipe away dust before primer.
Avoid: Do not sand aggressively enough to expose or damage the substrate.