Answer
For a bicycle frame before painting, scuff with 220 or 320, then refine with 400.
Why it happens
Round tubes and tight joints need light, even sanding so primer can bond without creating deep scratches.
Recommended grit
Use 220 or 320 to scuff existing paint. Use 400 before final paint prep.
Wet or dry
Dry.
Success check
The frame is clean, dull, and evenly scuffed around tubes and joints.
What to do
- Clean the frame thoroughly.
- Scuff old paint with 220 or 320.
- Use folded paper for tight tube joints.
- Refine with 400 before primer or paint.
Avoid: Do not leave glossy spots before painting.