2blu442

Hey guys
A couple of my project cars have thin paint and are now showing surface rust. I won't have the funds to paint them in the near future, but is there a product I could spray on them to seal up the metal and stop the surface rust? Either on the thin paint or if I grind off the paint and treat the metal with something. Is anybody familiar with a product that would work for this? I'll have plastic tarps over them through the winter months, but moisture still gets between the tarp and the car. John

joe_padavano

Is this intended to be simply a stopgap measure until you properly prep and paint the cars? If so, use a good quality epoxy primer. Also, don't allow the tarps to sit directly on the car. Provide airspace between the tarp and the car to allow the condensation to get out.

J-(Chicago)

I agree with Joe. I'd get as much of the rust off as you can with a DA sander, clean it up with some metal prep, and use something like PPG DP90.
That will buy you a decent amount of time until the rust shows back up. Epoxy primers kind of suffocate the rusty metal and it won't oxidize quickly if no more air is getting to it. Regular primers let more moisture in than epoxys.

2blu442

Thank you for your thoughts guys, yes this is just to prevent further deterioration until I have the time and money to get them painted. An example, the 1964 had zero surface rust but the sun from the desert environment where I got it had weathered the paint and much of the factory primer off. Last winter I covered it with tarps but didn't allow the air space so now I have surface rust on the hood, roof and deck lid. I had planned to get some paint on it this past summer but life was so busy I didn't get around to it. I'll use a DA to strip that off and shoot the epoxy primer on it before the winter weather really hits this part of the country. John

csstrux

just saw this, another option is marshyde one step rust converter. rattle the can and spray, done. I have been using it on my project now with stunning results, but only as a stopgap. $7 per can

Dapapadon

I try to stay out of the paint discussions because there is so much going on in that industry, things change quick. But I use PPG's DP series primers and they are a little different than standard primers.

If you use DP be sure to apply 2 coats for corrosion protection. One won't do it, ask me how I know. I can get pictures.

For lack of a better term PPG makes a slow and a fast reactive reducer for DP. The top coat time is longer on the slow RR. And the black DP (sorry, I don't remember the ##) can only be used with the slow. I do most of my paint work at the local comm. college. So I sand to bare metal, apply 2 coats of DP, wait and then topcoat with standard primer. The reason the primer goes on right after the DP is DP's recoat window is only 24 hours. And my 12 hour class is every other Sat.

Dupont makes a good enamel based non sanding primer that might work good for this and it's cheap.

Don

ijasond

If you are just going to put something on there that you will have to take off again when you do get ready to paint it. You might check out some other primers that would be comparable to the DP without the high cost. I've had much success with Kirker's enduro prime. It's very comparable to the DPs. You have a 7 day top coat/filler window and after about 3 days it sands surprisingly well, which can't be said for the DPs. Something to consider if you are watching your wallet like the rest of American's right now. I don't really recommend their urethane primers, they don't sand too well. Check out smartshoppersinc.com. They have some really great prices on most anything auto body related. I also buy the Indasa sand papers from them, the best quality I've found in such a low priced product.
Sand the rust down with a DA, clean it and treat it with a rust converter, then put the epoxy over it. Not even epoxy is designed to kill the rust, but the other guys are right, it will do much better than a urethane. Don't even consider acrylics, you'll be wasting your time and money.

Willidog

If it is not going to be exposed to sunlight you could just paint it with POR15 and then sand it off later when ready to paint.

Lady72nRob71

My recommendation, regardless on what treatment method you choose, is to loose the tarps and use a good breathable car cover. The "best" one at walmart for $69 would even work.
It is best for the moisture to escape, not be retained.
Standard plastic tarps are not good to cover anything metal for a long term (over a couple days).

ijasond

that's true. Well, I'm not sure about the car covers, but no cover is probably better than tarps. Putting a tarp over the car just ensures that the moisture will stay for extended periods of time, allowing it to work it's way into the paint rather than dry out. Paint, primer and just about every other coating you can imagine IS porous, they're just microscopic pores. So unless you are out there every couple of months sealing it up with a coat of wax or one of these new fangled polymers, moisture & dirt are going to get in. Do it once, do it right and take good care of it. It will last longer than you.