PS I didn't use Gardz because I've heard people can have problems with it blistering if you don't let it dry long enough. Plus I didn't have Gardz.

 

It's in a closet, so if you patch it up half decent it's probably good enough.

 

Should just be removing the drywall as high as needed and replace it. Drywall is so cheap.

 

I agree, but time is running short (many repairs left beyond the last minute). Homeowner (relative) talked to a handyman (who I thought would remove the drywall) who made it seem that washing it with vinegar and then "gluing" down the sheetrock paper to the gypsum was the way to handle it, and would be easy. Homeowner has no clue. So lots of less than desirable facts to deal with. It doesn't help that I'm not very experienced with sheetrock.

While to someone who has done a lot of sheetrock, removing the piece and patching in another seems like the right solution, the reality of life, time, homeowner's misconceptions, and my sheetrock (lack of) skill become factors. I wasn't confident I could do the corners well , or hide the horizontal cut across the sheetrock where I patched in a new piece. It doesn't help that the closet is in the attic and there isn't proper stud support across the back & bottom of it either (work probably done in the 1950s-1970s, possibly by then homeowner). Plus there are a few other oddities about this closet & wall. So, since house is being sold, and my skillset is lacking, the issue is being addressed in a less than perfect way.

 

I agree with the comments; if it was my house (1) it wouldn't have been left to the last minute; (2) the closet wouldn't have been packed full; (3) drywall would have been replaced..

I did get off almost all the paper with any mold on it. Watched some of "Vancouver Carpenter's" excellent videos on youtube to figure out how to do the repairs and learned a lot about mud & technique. Used 20 Easy Sand setting compound for first layer, and a little of 5 Easy Sand in 2 small places where the gypsum was crumbling (corners). Used plus 3 for the next coat; waiting for that to dry before applying another coat. Achieving a smooth finish is difficult but the videos give some good advice which is helping. Will see how it turns out It's fairly smooth now, but far from what a professional mudder would do.

I've been thinking about trying to skim coat a wall with a little uneven drywall in my house. Might start on an old basement wall to build my skills.

 

I've been thinking about trying to skim coat a wall with a little uneven drywall in my house.

Some of the first big walls that I skim coated I broke it up into manageable sections. Kind of like a checkerboard and then went back when dry to fill in the rest. Today I wouldn't want to spend that much time but it worked for me way back when.