Primers left to the wild

I am looking at doing prep to my newest truck, an 87 C20 TBI 350 TH400. The prep is going to take mare time than I can devote in one shot. There are a bunch of places that the metal is coming through the paint and I am going to have to start from there.

From my understanding, primer is porous and offers no protection from the wild. What can I do to protect my bodywork as I go along before I can paint the color? I am planning on going with a decent single stage enamel.

In reply to former520: Rust Bullit works as a primer and a sealer. I am redoing a 70 Mustang and has been a slow redo. Possibly 80% covered in it. My Merc's under side is completely coated in it. Its a daily driver for the most part. Most of the stuff I have done is roller or brush painted to start as later it will be sanded and spray painted my desired color.

My Merc is in readers rides the shot of the rear end shows the rear center section painted with it as well as the bottom of the trunk. Its been through 2 winters. Will be graging the Musting in the forum soon

Just a heads up, most primer is porous. Your fresh body work will rust nearly as fast if it doesn't have a sealer mixed in.

I've used an Epoxy primer on a few projects with good luck since it seals and has good corrosion resistance. My Miata actually sat outside in primer for a year before it was painted. No rust or an other issues Ive had with past primers. Over time it can fade or become chalky if left too long.

Yeah, Epoxy primer is definitely the way to go. It's more expensive than a standard porous primer, but it will hold up to the weather for long periods of time. We have a very nice paint shop here in Atlanta that we go to and they recommended we use this for one of our projects at Wreck Racing that had to sit in primer for several months. Worked great.

I would also recommend applying a layer of self-etching primer anywhere you have bare metal BEFORE applying the epoxy primer. Unfortunately this is pretty pricey as well and we're probably getting out the the realm of "grassroots" projects. I think this would be the best possible option though. Oh btw, that self-etching primer really requires a good respirator if you're going to paint any significant surface, as it contains some acid which is pretty nasty to breathe.

For small areas you can get self etching primer from NAPA in aerosol cans. It contains zinc chromate which is a rust inhibiter, but should be covered with an expoxy primer for moisture protection.

I too have always heard that primer obsorbs water. However, I once primered (standard lacquer primer) the bare body on my '70 Firebird and drove it that way for several years. I didn't drive it in the winter, but it did sit outside. It never rusted. Go figure.

My 74 impala just got a new coat of red oxide primer every spring and fall. Between the color and the constant application of primer for 3 years I never noticed any rust.. . .