Working on a project in my own house: in the main bath (drywall done about 15 years ago), skim coat on some portions of wall surface, near ceiling, is soft and flaking. I scraped off all soft material yesterday and applied a new skim coat with 90-min. mud. It didn’t bond to the old material. The hardened new skim coat pulled away from the old surface, like tape that doesn’t have enough mud underneath.
What did I do wrong? Did I need to dampen the old material before adding the new skim-coat. Dig farther into the existing drywall. I’m a painter, not a drywaller, but this is my own place so its my puppy to deal with.
Replies
Prime the old stuff first with oil or alcohol base primer.
My suggestions- make sure room is as dry as possible ( no showers for a couple of days ) and ventilated.
remove all loose material, and make sure substrate is dry
prime area with Kilz or similar primer, let dry.
apply hot mud, dry, sand, and prime again
touch up and spot prime if needed.
paint.
Moisture is the problem. Everything needs to be dry for good results.
Check your exhaust fan and see if it is working right, and use it frequently.
Thanks for responding. The room is dry, but I'll prime before skim-coating. Stay tuned for results -- should take a day or two before I know. Onward and upward.