As Ive stated on this forum before Im curently spraying my old ford with epoxy primer after taking it down to bare metal. I do all the body work I can with a hammer and dolly and minimal amount of filler f neccessary. I then spray on two or three coats of ppg epoxy primer and if I can see any defects I will go back over them and spray on more primer. This is a slow tedious process, but I have lots of time. As I finish a panel I sand it with 600. Im almost finished and so far Ive used two gallons of epoxy primer which I know is a lot but sometimes I would redo a panel that I wasnt satisfied with the results. I think the cars looking great but Im concerned with the thickness of the epoxy primer. I mean if you cannot see the metal thru the primer is that thick enough? I realize that most of you guys do production work and because your under time restraints you use 2k high build primer. I looked at a buddys car yesterday and hes applied 2k primer over epoxy an I swear it looks an eighth inch thick. Am I gonna be O.K. as long as the body works good or do I need to go with some 2k primer over this stuff?

You are asking if its too thin so I take it you have removed most of the epoxy while block sanding.
Since you are sanding to 600 grit does that mean you are planning to go straight to applying color?

as long as you dont see metal through the epoxy i would say your ok as far as mil thickness goes. 2k wont really do anything for you at this point. once you get it all right with epoxy and its ready to base out reduce the epoxy down as a sealer, shoot 1 coat and go right to base.

yes,Im planning to go directly to base after spraying on a sealer.

jim c wrote:as long as you dont see metal through the epoxy i would say your ok as far as mil thickness goes. 2k wont really do anything for you at this point. once you get it all right with epoxy and its ready to base out reduce the epoxy down as a sealer, shoot 1 coat and go right to base.

Took the words right out of my mouth or is that fingers now?.

Sorry for the juvenile question but what if he's going with a pretty light colored base? Would you be concerned about UV hitting the epoxy? I was under the impression that the 2k is used to help further block UV from hitting the epoxy (not the only reason to use 2k mind you).
Cheers,
cc

You may want to read the data sheet for your epoxy.

I use PPG Epoxy Urethane Primer (410-48248) quite often and I can tell you that base coat cannot be shot directly onto the epoxy - it needs a primer of some sort on the epoxy and before the basecoat.

yes, most of all follow the tech sheet for the primer you are using. i have never heard of not being able to base on an epoxy primer but every paint company has their reasons. whats funny about the ppg stuff you mentioned is its a epoxy/urethane which the whole point of the paint companies making that stuff is so it can be a 1 shot deal and you wont need 2 primers to get the job done. kinda funny you cant base on it.

as for uv, even with a light colored base the uv isn't going to penetrate the clear, go through the base and start breaking down the epoxy. the basecoat would actually break down first and the clear would peel if that was the case. i know a ton of guys that just use epoxy primer all the way to base and i know even more that use it as a sealer just under basecoat. with all that said, follow the tech sheet as all epoxies are not created equal.