Answer
For exterior door refinishing, use 120 for old finish cleanup, then 180 and 220 before new finish.
Why it happens
Old finish and weathered fibers need controlled removal and refinement before new finish.
Recommended grit
Use 120 for old finish cleanup, then 180 and 220 before stain or clear finish.
Wet or dry
Dry.
Success check
The door surface is smooth, clean, and even before finishing.
What to do
- Remove loose old finish.
- Use 120 where old finish or weathering remains.
- Refine with 180 and 220.
- Clean thoroughly before applying new finish.
Avoid: Do not sand through decorative edges or veneer skins.