Answer
For dried paint sags on trim, level with 400, then feather with 600 before recoating.
Why it happens
Sags need to dry hard enough to sand without smearing, then be leveled and recoated.
Recommended grit
Use 400 to level small sags, then 600 for smoother trim repaint prep.
Wet or dry
Dry.
Success check
The sag is level and the trim surface is ready for another coat.
What to do
- Let the sag dry fully.
- Level the raised sag with 400.
- Feather the repair with 600.
- Remove dust before recoating.
Avoid: Do not sand soft paint that still gums up.