Q: The previous contractor oversanded the drywall, and the paper backing has furred.  What steps should I take to repair and prepare walls for  a professional finish?  

Get Dust Off The Wall

Clean any compound dust off the drywall. You can accomplish this quickly by  using a broom or a soft microfiber mop  head; I’ve even seen painters use a leaf blower on larger jobs. Then vacuum any  compound that has fallen to the floor so it doesn’t get kicked back up into the air.  Prime the “drywall burn” with an oil-based shellac. This should prevent the  sore from flashing at an angle. Once it is  dry, sand smooth any raised paper, then prime and double coat the wall.  

Lock Down Loose Fibers

If someone has oversanded unpainted drywall and caused the paper to fur, the first step would be to remove any residual dust left on the surface. Once it is clean, use a high-quality primer such as Sherwin-Williams Pro Block Primer to lock down any of the loose fibers.  

Once it is fully dry you should be able  to give the surface a light sanding with high-grit sandpaper to smooth things out. If you originally sanded past the  paper directly into the board, you will  need to apply a tight coat of drywall compound to this area after priming.  Priming is essential, as it will do three  things: lock down any loose particles, show any flaws and, of course, make for  ideal adhesion.

Create a Safety Barrier

Matt Rathgeb, Matthew Rathgeb  Painting, Philadelphia, PA  Sometimes the taper that comes  ahead of you oversands—“drywall  fuzzy” is a real thing. I clean the canvas,  then prime. That won’t cure fuzziness,  but that way, you can sand it without re-damaging the drywall. Primer will seal it and serves as a safety barrier between drywall and sanding. Then I lightly sand and use spackling over the fuzziness—the spackling  smooths it out. If there are still rough  areas, we spot patch after that.