Answer
Use 320, then 400, then 600. Keep pressure light to avoid gouging or heat marks.
Why it happens
The surface needs gentler step-by-step refinement to avoid deep scratches.
Recommended grit
Use 320 or 400 for prep, then 600 and finer for a smoother finish.
Wet or dry
Wet for fine stages.
Success check
The surface feels even with a controlled fine scratch pattern.
What to do
- Clean the plastic.
- Use light pressure.
- Progress through finer grits.
- Rinse residue before each finer grit.
Avoid: Do not use heavy pressure that can gouge or heat the plastic.