Auto body repair & detailing: primer drying, acrylic lacquer, lacquer thinner

Question
When I apply my primer coat It never seems to dry.
I'm In a garage temp varies 65 to 70 I wait a day or two drying time and when I try to sand it clumps up and when I use prep-all to clean It comes off Why?
just painted my dash waited 4 days and it still clumps Just dawned on me to look at the humidity level It was 70% is that to high

Answer
what sort of primer you using? If it's a 2 part catalyzed, (many catalyzed primers say 2K on the label) and you aren't putting in catalyst, it won't ever cure- when you paint it, it will probably lift and craze. Are you using proper thinner if it's lacquer primer? You must use automotive lacquer thinner, the stuff you get at Ace Hardware won't work in acrylic lacquer primer. Are you using primer surfacer, or primer sealer? Sealers aren't meant to be sanded or blocked. They are a final coat before painting, they will only fill 400 or 600 grit sand scratches, and make a uniform color base for the paint. Some are metal etching. You need a 2 part catalyzed primer surfacer, or Lacquer primer surfacer, with the proper components. If by chance you are using the proper components, your catalyst may have gone sour. It goes bad, slowly, once you open the can. Some are only good for a couple weeks after you open the can. Bill