Thread: Surface rust

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I now own my dads old 1979 F250 that he had two cheap piant jobs on! The hood and roof are pretty rusty. I have sanded down to the bare metal but there are these blotchy spots that look rusty. I have contined to sand these areas. Question is do I need to get all the metal to look the same color or what should I do? How far do I need to go?

You need to get ALL the metal to look the same with NO black or darker spots left at all. It needs to be a nice shiney almost looking metal. If I were you, I would do each panel, fender, bed, etc at a time which consists of taking each one off, sand it down to bare metal, clean it good and primer it and put it aside and move on to the next part. That is so you don't get surface rust the next day because if you sand it to bare metal, most likely you cant sand it all down and primer it in one day and surface rust comes back overnight.

Good luck!

I did go back and sand, sand, sand, boy do I have a new respect for guys that pick up rusty old cars and make them sharp. I think I sanded about 20 hours just of the hood and the roof. Using 40 grit paper. But it did come out pretty good!

My wife and I were on the way to town yesterday and I saw an old 48 chevy on the trailer. I commented that looks like a lot of work. But I'm having fun! Finally was able to put the etching paint on today! Now I can see a few places that need a little more work.

I used the Nason etching/primer so now I need to get primer and see how that works! Any tips?

it sounds like you are sanding it all by hand, if you are go get a dual action ( D/A ) sander. it will be the best money you ever spent. they do take a ton of air to run though.

Sevenson, The most important thing you can do is to use metal prep on the pitted areas before you prime. It contains Phosphoric acid, which changes the rust from iron oxide (which is active), to iron phosphate (which just lays there forever).

Another option is to sand it as well as possible, then use a self-etching primer (which contains phosphoric acid). Jay

Any body shop can help you with advice on how to use these products.

One more thing I should mention....If you use a primer-surfacer, it will let moisture get through, and start the rusting all over again.

You will want to use a primer-sealer or better yet, a catlyzed urethane primer.

after you're done putting on your etching primer and primer, if the colors are still blotchy use a tintable sealer to get everything to one color. The sealer will also keep the primer from absorbing water. good luck painting. drop off some pics when you're done.