Sanding

The process of sanding the joint compound to make it smooth and feathered in with the drywall paper. Large power sanders are often used with 9" circular pads and a HEPA vacuum that sucks up the dust. Grits used are 120-240. 220-240 suggested for lightweight joint compound(Blue or lime colored lid), 120 grit for all purpose heavy weight joint compound such as darker green lid USG. Source: Jason Lebeau a 24 year drywall industry veteran.

Sanding drywall is the essential process of smoothing dried joint compound (mud) on taped seams, corners, and fastener spots to create a flat, uniform surface for primer and paint, typically using sandpaper or sanding sponges with grits like 100-220 for feathering edges, removing high spots, and blending transitions, often done wet to reduce dust but producing significant dust when done dry.