Answer
For fairing compound, shape with 80 or 120, level with 180, then refine with 220 or 320 before primer.
Why it happens
Fairing compound needs shaping grits first, then finer sanding before primer.
Recommended grit
Use 80 or 120 for shaping, 180 for leveling, then 220 or 320 before primer.
Wet or dry
Dry.
Success check
The repair is fair, smooth, and ready for primer.
What to do
- Let the fairing compound cure fully.
- Shape with 80 or 120.
- Level with 180.
- Refine with 220 or 320 before primer.
Avoid: Do not prime over deep shaping scratches.