Sand to flatten — not to carve
The goal is feathered edges and flush fasteners, not glass-smooth gypsum. Over-sanding cuts into tape and creates waves that show under paint. Light pressure, long strokes, and a work light angled across the wall reveal ridges.
Mud must be fully dry before sanding — cool damp rooms need overnight or longer between coats. See how many coats of mud.
Grit and tool sequence
Shop-vac pole sanders with shrouds cut dust dramatically. Hand pole sanding still needs plastic on floors and a sealed doorway.
- After embed / first coat: knock high ridges with 120 grit if needed — often knife scrape is enough
- After fill coats: 150 grit pole sand for flats
- Before primer: 180–220 grit touch-up on visible scratches
- Corners: sanding sponge folded — keep from rounding the corner bead face
- Never sand through paper tape — stop and skim another coat instead
Dust control that actually works
Wet sponging can reduce dust on small patches but is slower on whole rooms and can raise the nap of paper. Use for repairs more than full hangs.
- Plastic zipper door on the room; cover HVAC returns
- Negative air: box fan blowing out a window if weather allows
- HEPA or drywall-rated vac — household bags clog and blow dust
- Wear a proper dust mask; drywall dust is fine and persistent
- Vacuum between coats before the next mud pass
When sanding is done
Wipe or vacuum dust, then check under raking light. Skim remaining hollows, dry, final light sand. Next: prime new drywall before paint. Finish level targets: finish levels explained.