I'm thrilled to find this website and hope someone can help answer my questions. I would like to paint a ceiling that currently has a "popcorn" finish. I'd like to change the texture of the ceiling and wondered if I could accomplish that by applying joint compound over the "popcorn" finish. If so, do I need to apply a primer/sealer to the ceiling BEFORE I use the joint compound or apply the compound directly to the ceiling (as is), wait until it dries, and then apply the sealer/primer before I apply any paint? I also thought about using ceiling spackling but it seems more lightweight and "crumbly" in texture whereas the joint compound has a smoother, heavier texture that I think will produce the results I'm looking for.