Long story short...Scrapped all the paint off 800 sq' of my house. The paint came off easily in huge sheets. I am left with walls that are down to drywall in some spots, fully covered, or half cover with a yellow,chalky,powdery film that can't seem to be identified. It is either the world's worst yellow primer or the world's worst builder's paint. Obviously, I can't paint over it and have a decision to make. Do I seal, skim coat, seal, prime, paint or rip the nightmare surface down and put new drywall? The existing drywall was glued with a few screws/nails and has separated from the studs in some places. I have gotten quotes of all sorts but the one constant is everyone tells me they have never seen this before!