good night, you'd know what hardener used primer before repainting the ceiling? This is an old vaulted ceiling and a priori plaster paint nature?? the first attempts in the kitchen have generated some difficulties: the crumbling plaster, blister and a very average result with the ceiling of a room to repaint soon I wonder what kind of primer applied before the painting?
from what you say, the ceiling would it not painted with lime which was added a little more blue to identify the white effect, or tempera? If this is the case, (milk of lime) wash, then if necessary use a filler coating quality, sand and paint with good paint ceiling