Patch Blister

darnoc2

I recently repaired a ceiling with dryall and fiberglass tape with hot mud. after finishing the patch i primed the area and some blisters appeared where the mud was over the old painted surface. the mud actually came off. i've never had this problem before. any insights?

Tim0282

Sure have had that problem. Bummer, too.
I have started priming the area around to make sure the mud sticks to all of the surface. Prime plenty wide. Best to use an oil base or Zinser 123. Then prime again over the mud. Durabond is known for doing that. All fast set is. Regular mud won't as much, but still safer to prime first.

darnoc2

Thanks for the reply. Now how do I fix the problem without starting over from scratch?????

Tim0282

You should be able to scrape the loose and just coat with mud and be fine.
Might be best to use regular mud or Easy Sand rather than Durabond.
Operative word- should...

darnoc2

Actually easy sand 20 min is what I was using. Do I need to prime the area before applying new mud?

Tim0282

I wouldn't. Don't think you would need to.
It is surprising the first time let loose. Was there a moisture problem that caused the need for the patch? Was it over plaster or drywall? You may have already said in earlier post. Trying to figure it out.

darnoc2

The patch was to repair ceiling where plumber cut holes to find leak from upstairs bathroom. no serious moisture problem. all seems dry. original ceiling was drywall with plaster skimcoat. painted with satin finish paint. I'm thinking that there might have been grease or dirt on surface that was not detected as this was in kitchen area. I will remove any loose spots and sand into painted areas to get better adhesion. thanks for your help

Tim0282

I'm betting there was moisture trapped between the finish plaster and the paint. The must just was too much and released. Just about every time something does that, it is moisture related in one way or another. Youe should be good to go.