Help! Paint is peeling from plaster walls
A couple of years ago, I painted the hallway in my 135-yo house. The painted plaster walls seemed to be OK, so I just filled a few smalls nicks and spot-primed, and then painted with a latex paint. Recently I noticed that the paint is separating from the plaster, and in some spots can be peeled off like wallpaper, leaving bare plaster. The paint that I applied adhered to the paint that was already there, and ALL of the layers are pulling away. I think that the latex paint may have shrunk slightly and pulled the underlying layers from the wall. The worst area is near an old radiator.
Is there anything I can do to prevent this the next time? Should I use Gardz or some other product before priming and painting? What primer would adhere best to the plaster?
Now that I can examine the bare plaster, I can see that it's not in the best shape, but I'd like to avoid re-plastering (just fix a few bad spots).