Temporary paint for fender

[Richard Lorenz]

I am restoring a '31 Coupe and have 2 front welled fenders that were sand blasted several years ago and are starting to rust. I would like to use them temporarily until I have time to finish restoring the plain front fenders that will be permanent.
I would like to paint the welled fenders with something that can be easily removed by some future restorer. I have some black acrylic lacquer that might be suitable, and I could use some rattle-can primer-filler that is a soft paint that might be easily removed, both with a future sand blast.

Does anyone have a better suggestion other than completing the restoration of the plain permanent fenders?

[Logan]

Use a DA with 80 grit, or use something to scrape away the rust that is there, then prime them and they should be okay till you or someone else gets around to them.

[Charlie Stephens]

Many primers are porous to water. Be sure you get a water proof primer of put on a quick top coat.

Charlie Stephens

[J Franklin]

Wash the fenders with OSPHO, follow instructions and prime with epoxy catalized primer, top with a few coats of black lacquer. the OSPHO will treat the rust, the epoxy is not porous, and the lacquer sands easily for further topcoating. Don't sand with 80 grit unless there is a good reason for doing it. I wouldn't even sand the bare metal with anything more coarse than 150 grit unless there was heavy rust. Light rust discoloring that happens after sand blasting will go away with the OSPHO treatment.

[pooch]

I use 36 grit on my freshly blasted surfaces and have done so for 35 years.

Never with a disc sander, only an orbital.

[jr-41ford]

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Richard, after you remove the surface rust, prep the fenders for paint, then just use your rattle can primer and acrylic lacquer. Should be fine from keeping the surface rust from returning and will be easily removed when it's time to restore and paint them correctly.

[29 model-a]

Originally Posted by J Franklin

Wash the fenders with OSPHO, follow instructions and prime with epoxy catalized primer, top with a few coats of black lacquer. the OSPHO will treat the rust, the epoxy is not porous, and the lacquer sands easily for further topcoating. Don't sand with 80 grit unless there is a good reason for doing it. I wouldn't even sand the bare metal with anything more coarse than 150 grit unless there was heavy rust. Light rust discoloring that happens after sand blasting will go away with the OSPHO treatment.

I agree with j Franklin

[tbirdtbird]

For heavens sake stay away from lacquer. Modern urethane paints will lift and bubble it and make a heck of a mess for the next person. I am dealing with this very issue right now on a '61 Rolls I am working on for a customer. They will have to be blasted all over again.

They should have had the Ospho (phosphoric acid) treatment right after blasting and if so, they would not have rusted at all. Use it now by spraying it on and then play the flame of a propane torch lightly over it to catalyze the reaction, then wipe it off. Do this several times until you have no more rust color on the rag. This means all the rust has been converted to iron phosphate which is very stable and will not rust; and is the best surface upon which to apply other products.

If lacquer were so good the car companies would still be using it.

[J Franklin]

I have shot catalyzed urethane topcoats over lacquer and never had a problem. The idea of using lacquer is that a few passes with a sander and it is gone anyway, I wasn't advocating 20 coats like old show car jobs.

[antiquepa]

What ever spray can of primer you use, just get a can of clearcoat in a spray can and you will be ok till you get back to your regular paint job. Primer will absorb moister and the clear will prevent this from happining..done it...works for me!!

[Logan]

Originally Posted by J Franklin

Wash the fenders with OSPHO, follow instructions and prime with epoxy catalized primer, top with a few coats of black lacquer. the OSPHO will treat the rust, the epoxy is not porous, and the lacquer sands easily for further topcoating. Don't sand with 80 grit unless there is a good reason for doing it. I wouldn't even sand the bare metal with anything more coarse than 150 grit unless there was heavy rust. Light rust discoloring that happens after sand blasting will go away with the OSPHO treatment.

We strip sheet metal with 80 grit, and if we have to we use 36 grit on a 3 inch disk grinder to get out tough rust. It doesn't hurt the metal, and as long as you are careful with the 36 grit it won't mess up the metal. The key is to keep the sander/grinder moving, and not stop in one spot. If there's any grind marks left behind, primer will fill them. We usually do about 4 maybe 5 primer blocking during the prepping for paint. If you only block your sheet metal 1-2 times you might see SOME little grind marks in places like the hood loovers and little nooks and crannies like that. But If you prime and block sheet metal correctly then you wont see any differences.... This is just my opinion I'm sure your way works just as well.