Hot Mud On Plaster?

Murphy

We were called in to help sell this old house, one of the problems was that two of the walls had bubbling on them. So I talk to my drywall guy and he says just scape off the bubbles and skim coat with 45.
By the way the bubble appear to be water damage that they assure me has been fixed for years since they got gutters.
So I scape sand off all loose every thing and skim coat.
My skim coat appeared to be bubbling out also.
Can some one offer some advice???

mdshunk

You need to get a moisture meter, brother.

Murphy

I was thiinking that too the house seems to have that old aluminum siding that I'm guessing they wrapped over the existing siding, and I am afraid maybe the moisture is stuck in the wall.

Danahy

Not knowing exactly what the conditions are for you, all I can do it warrant a guess. Anytime I'm doing anything patch wise, on anything plaster like... oil prime

Oil prime obviously over the patch work, but if you're getting air flow behind the bubbles or moisture, try priming first, patch then prime again.

Confused as to your 45 bubbling?...

Murphy

Prime area that I just sanded down before I patch with 45 easy sand??

Frankawitz

Could be a couple of things going on here, one if your patch is bubbling up there could be oil base paint that will not let the easy sand bond to, or two there still is moisture in the plaster which won't let the easy sand bond to. I would say it's number one. you need to sand it real good with 80 grit then try patching, if it don't work then there moistrue in the plaster. Where is this repair at in the house in a inside wall or outside wall that this is happening to? Got a pictrue you could post?

Murphy

Inside wall and I sanded with 60 grit first. I have a pic but I don't know how to post it.

steve336

Is there any wallpaper left over thats been covered up over the years?
If so that would cause this.

Frankawitz

try to post your picture in the gallery. is there a upstairs bathroom above the area were your having problems?

Murphy

No upstairs bath I will post before and after pics when I am done.

smooth

This is common when you skimm over a painted wall. The air in the mudd comes to the front instead of being absorbed, because of the primer and paint sealing the wall. I have found that a fast setting compound works well on the first coat so the bubbles don't have time to form. All you can do now is keep skimming with a thin mix till they disapear. Add a little fast-set.
after re reading your post I don't think you talking about fish eyes , dig out the air bubbles and refill them.The layers of paper in the drywall have seperated , trapping air.