My 67 SS 350 has been in dry storage for many, many years. It has spent a few years with the body (except underside) mostly in bare metal. The underside I had sandblasted a long time ago and painted it with GM Chassis Black. Over time the chassis black has had some rust show up. So, as soon as the weather dries up this summer I plan to move it outside and re-blast the underneath then repaint it with DP90 epoxy primer. I am thinking that I would also paint the body with DP90. Breaking this apart into two separate processes:

1) What is recommended for the underside to finish over the epoxy primer? Does it need an additional primer before finish? What is the best durable finish top coat since the underside takes a beating for road debris?

2) It will be a while (maybe a year) before I can finish paint the body but I want to get the bare metal covered right away. Is it ok to just paint it with DP90 only or should I shoot an additional primer over the DP90 to protect it until I get to finish coating it?

Thanks...

 

The top coat for the epoxy primer is totally up to personal preference. You can use chassis black, or if you want an even stronger coat you can add some ceramic paint on top. Or you can go all out and use bed liner for a super tuff coating. Your epoxy primer is 5-10 times stronger then what the factory put on the car original so as long as you prep it and its a weekend warrior it will most likely out live you. Unless you live on a gravel road I do not see any reason to add more on top other then for looks. I would guess the reason your original paint rusted is because you did not use a acid etch primer under the paint. Anytime you have bare metal you need acid etch paint, the acid kills the flash rust that happens almost instantly. The epoxy primer will seal everything up and not allow the flash rust to grow so acid is not needed.

Think of the epoxy primer like it was a thin coat of fiber glass. You could store metal under water if it had a proper coat of epoxy primer on it. I don't think it is an issue anymore but read your instruction, some epoxy primers get so hard after a week or a month you can't even paint them. All that info should be right on the side of the can.

You are right to ask because many other primers absorb moisture and will rust if not protected by some other means. That just not how the epoxy primer works.