Answer
For polycarbonate, wet sand 800, 1000, 1500, 2000, and 3000, then polish.
Why it happens
Coarse scratches in polycarbonate are difficult to remove, so fine wet sanding and polishing are needed for clarity.
Recommended grit
Use 800, 1000, 1500, 2000, and 3000 before polishing.
Wet or dry
Wet.
Success check
The surface has an even fine haze before polishing.
What to do
- Clean the polycarbonate surface.
- Wet sand with 800 or 1000.
- Refine with 1500, 2000, and 3000.
- Polish after sanding for clarity.
Avoid: Do not start with coarse grit on clear polycarbonate.