How to Skim Coat a Wall After Wallpaper Removal

Sand the entire wall using a medium-grit sandpaper. Wipe the wall with a damp rag to remove any drywall dust.

Use a putty knife to apply a small amount of joint compound onto the edge of a drywall trowel. Holding the trowel at a 90-degree angle, apply a light, even coat of plaster onto the surface. Do not apply more than 1/4 inch of plaster at a time. Fill in all holes and dings on the wall's surface using the trowel and joint compound. Compare the technique to icing a cake or buttering toast. Allow the first coat of plaster to dry about four hours.

Lightly sand the dry plaster with a fine- to medium-grit sandpaper to remove any loose plaster. Wipe off any dust with a damp rag. Add more wet plaster to the wall with the trowel, allow it to dry and continue the process until all grooves have been filled in and evened out. Several layers of joint compound may be necessary.