I have an older home with plaster walls. I painted my bathroom walls and once they dried they were peeling, bubbling and getting extremely deep cracks. So I scraped them and sanded the walls down and put primer on them and I painted again. The same thing happened. Before I painted it almost felt like it might of had an oil based paint on it. But I did sand it down and it didn’t help. I didn’t know if maybe it had something to do with moisture in the bathroom but I am desperate for advice!! Thanks!
Sounds like surface contamination. Common cause is accumulated soap scum but hair spray and similar products can also cause problems.
Old surfaces require extensive prep before painting with oil base paint needing a little extra. Typically this involves a good washing and sanding before priming.
Since you have already painted there isn't much that can be done except the following;
* Scrape off all peeling and loose paint.
* Sand with 120 grit paper or medium sanding sponge.
* Washing and extensive rinsing with fresh water would be nice but this will loosen more paint.
* Prime all surfaces with a shellac primer. Could take 2 coats.
* Patch any bad areas; peeled paint areas and deep scratches from scraping.
* Spot prime if there was extensive patched areas.
* Paint again.
I don't like acrylic primers on old surfaces, doesn't work well. Either a shellac or fast drying oil base primer is used with the shellac being the best.
Also, reduce humidity during the curing phase and it is a good idea to do this all the time so there isn't future problems.