I have painted ceiling tile in a mobile home before. I used Klitz stain cover primer and then ceiling paint. It worked well. I don't think the ceiling tile was acoustic tile though.
I would take a tile v-notch trowel or wire brush and scratch the paint before putting mud over it. Not deep enough to scratch the paper, just enough to leave visible scratches. If you were painting instead of mudding you'd use a deglosser or lightly sand the paint to get rid of any shine. Oil-based primer was preferred for water based paint for years. It is subject to restricted use in some areas now .
Yea, I removed 2 sets of rotten nasty French doors 60 x80 openings and installed a glass slider on chosen entry left side of family room and on rt side installed a 40x60 slider window. Reframed, installed a double 2x8 header for rough in and installed windows Previous owner painted walls w oil based paint . I sanded area smooth and mudded joints ok. No issues. You will be ok w mudding over. Just be sure to use fiberglass mud tape for the joints. Paper tape is a pain and isn't very strong. Prob did the job already?? Lol
No, we haven't done the job yet. I was going to go over during my Spring Break and prep the room ( clean it out and wash walls) but we have colds here and I don't want to take them to Mom. It would be nicer to do it in the warmer weather as well. So it could be a month or three before I start.
I didn't read the entire thread but I have drywall experience from my construction days. The only concern I worry about when it comes to renovations and old binders is calcimine based paint or primers. Once any work, to include painting, is done over a calcimine painted surface the bonding agents tend to release when the new work is placed onto of the old work. Compound and plaster will eventually start to release and come off in large sections. Compound has a small bit of oil added to it's blend and that acts as it's adhesive when it's applied, although it is water based and can be cut for workability. Calcimine surfaces have to be scraped off or removed.
I don't like mesh on an inside corner. Personally I think stickied, fiberglass mesh is for people that don't know how to use paper. And there's nothing wrong with that.
A properly done paper joint gets its strength from the WET bond of the glues in the compound with the paper. Works very well. the fiberglass cracks and breaks easier than a good paper joint....
