I’m a do-it-yourselfer.
I’ve been drywalling for 25 years and I’ve done my share of basement rec-rooms and household repairs.
Over the last few years I have been having problems with applying drywall mud. I usually use the Ready-Mix All Purpose Compound.
The issue is with applying mud over a previously painted wall to fix a crack, nail pop (etc).
When I apply the first coat of mud I don’t see any problems.
However, when I apply the second coat I usually get a pile of bubbles.
These bubbles will not go away no matter how many times I go over them with the trowel… well I could spent 5 minutes on a spot and reduce them to fine bubbles but typically they do not go away.
When mud dries I have to sand off the bubbles and then apply a very fine coat to fill the pin-holes.
This is extremely annoying and I don’t remember it happening to me prior to a few years ago. I don’t think that I have changed my technique.
Is there a solution to this problem? Is it a problem with using Ready-Mix All Purpose mud. I’ve seen some posts that suggest that it is the paint, but then why is this only a recent thing (maybe in the last few years it started happening to me).
A picture is attached. In this photo I repaired a crack in a tapped joint by removing the compound covering the tape, putting in a new strip of tape and covering it with mud. Then on the second (and subsequent passes) I get the bubbles as in the photo. I think the photo is on the thrid pass. You can see that they do not occur over the joint (where there would be no paint).
Any ideas/solutions would be appreciated.