Answer
120 grit is for early smoothing and prep. Follow with 180 and 220.
Why it happens
120 grit is useful for early smoothing and moderate prep after coarse grits.
Recommended grit
Use 120 after 80 or as a starting grit for moderately rough surfaces, then 180 and 220.
Wet or dry
Dry for most prep.
Success check
The surface is smoother and ready for 180 or 220.
What to do
- Start with 120 on moderately rough areas.
- Sand evenly until roughness is reduced.
- Clean dust.
- Move to 180 and 220.
Avoid: Do not jump from 120 directly to ultra-fine grits.