Answer
For plywood edges, use 120 for rough saw marks, then 180 and 220 for final prep.
Why it happens
Layered plywood edges expose different grain directions and glue lines, so they need gradual smoothing.
Recommended grit
Use 120 for rough saw marks, then 180 and 220 for prep.
Wet or dry
Dry.
Success check
The edge feels even and has no sharp splinters or saw marks.
What to do
- Sand rough cut edges with 120.
- Refine with 180.
- Finish prep with 220.
- Keep the sanding block flat to avoid rounding the edge too much.
Avoid: Do not start with ultra-fine grit on rough plywood edges.