I know I should have done this earlier, but I'll be getting my car sandblasted in 8 hours, and I still can't make heads nor tails of the best primer system to use. Should I use a zinc-chromate primer, an epoxy primer, or a wash primer? Any specific product recommendations? The car will still need much bodywork and metal R&R before it is ready for paint. AlsoKeep in mind that I am outside the US and have no access to POR-15... I'd really appreciate your suggestions, thanks!

Omar, you should use an Etch Primer first.

You can use vinyl wash if you will be starting bodywork right away.
If you're going to wait use the epoxy, I like PPG DP40.

Epoxy...its waterproof, the car will survive outside without getting surface rusty, and you can shoot primer/sealer over it when ready.

epoxy is very hard...when you are all ready to paint...after all the metalwork is done, just scuff it up and shoot a good sealer...then off you go.

Rich

BEST results will be to use an etch/wash primer. Next best would be epoxy. The etch/wash primers adhere MUCH better and will also neutralize any small rust pits that may be left as well as any rust flash that may occur once bare. I have a Jeep hood that has NOTHING but Spies etch primer on it. Been outside for almost a year...in the rust belt south. NO rust except where it was scratched pretty hard and the rust has NOT spread under the primer on the edges of the scratch. There is a damn good reason I use Spies Hecker.

I think once you've hammered on PPG dp90, 40, 74 LF you will decide it's pretty good stuff. I bead blasted some aluminium sills for a jeep truck hunting wagon and 5 years later it still hasn't rubbed off. They say plastic filler won't stick to it but I think it sticks better than to bare steel and it's sealed to stop rust from forming under the filler. Just sand blast a piece of scrap metal, paint it with dp epoxy let it dry about 12 hrs. don't even scuff it and put some rage gold filler on it. Let it dry and try to tear it up after about two days.
Charliew