Answer
Coarse grit leaves deep scratches. Refine step by step through medium and fine grits.
Why it happens
Coarse grit removes material quickly and leaves a deep scratch pattern.
Recommended grit
Refine through the next grits in order until the coarse scratches are removed.
Wet or dry
Dry for early refinement; wet for fine finishing stages.
Success check
The deep coarse pattern is replaced by a finer even pattern.
What to do
- Stop using the coarse grit once material removal is done.
- Move to the next medium grit.
- Inspect for remaining deep scratches.
- Continue finer step by step.
Avoid: Do not try to hide coarse scratches with only ultra-fine grit.