RE: CGrace28 post:

I have alligatoring primer that was applied over new and previously painted bathroom walls. Since the substrate is sheetrock, stripper is not an option. I have had little success, little meaning approximately 1 square foot per hour, sanding with either 1/4 sheet or 5 inch DA sanders with 60, 80, or 120 grit paper. This particular primer becomes so smooth during sanding that it seems like I am trying to sand ceramic.
I have not tried a heat gun. Are there any other solutions besides replacing the sheetrock?