My purple board has lost some of the paper on it. Not all of the paper, but some. Also some on some greenboard as well. I alreayd have to compound some tape and corners in the area. Can you just use joint compound over these areas as well, or is there a better way? i have included a picture of several areas.
Answer; cut out layers that are frilly as much as possible... if you do not go down to the gypsum (not sure what to coat that with) then coat it with a Primer Sealer. Some said Oil Base.... I used a water base like Bulls eye or Gardz or Kilz
I can't remember where I found this, but it worked well for me.
1) Cut away all the fuzzy paper edges, but stay as shallow as possible.
2) Prime the exposed gypsum, as well as the cut edges with PVC primer.
3) A thin coat of hot mud (I used 90 minute...so maybe not all that hot...) to bring the surfaces even.
4) Thin coats of joint compound, sand, repeat...
5) Prime, sand, finish.
That's just my opinion. But it's free, so take it for what it's worth to you.