Rust under paint

showcrop · Jan 22, 2012

I got around to removing paint from a fender today. I went through lots of preparation because the primer was yellow, so I was thinking it was chromate, even though it was pretty pale yellow. Well as I was blowing it off with the abrasive disc I got into lots of rust under the paint, just as if it was just plain old 35 year old lacquer primer, with no rust prevention. It is my understanding that chromate in paint is a very effective rust inhibitor. Just another case of leaving just a tiny bit of rust here and there and it grows like wild fire under the paint. Looks like another good advertisement for acid wash.

CNKS · Jan 22, 2012

Every tractor I've worked on has some rust under the paint, if there is any paint left-- mainly because as a hobby I pick the worn ones. If there is rust in the pits I can't sand out I use Picklex 20 or Must For Rust, which are good for killing the rust in the pits. When I'm getting ready to paint, I scuff it with a scotchbrite pad and then use wax and grease remover. I don't wash it off. No further problems. A quart of the stuff lasts me for several years because I only use it where needed.

RandyB(MI) · Jan 22, 2012

Hard to tell what it actually was. Today , deceptive advertising and labeling is rampant. I've seen spray bombs labeled "epoxy" , zinc cromate" , urethane and many other hi-tech names. Look in the fine print on the can and it is either enamel or laquer/acrylic laquer. Government has no resources to police this or any other of our laws to protect consumers. Get with a reputable auto restorer for your questions.

showcrop · Jan 22, 2012

(quoted from post at 19:27:31 01/22/12) Hard to tell what it actually was. Today , deceptive advertising and labeling is rampant. I've seen spray bombs labeled "epoxy" , zinc cromate" , urethane and many other hi-tech names. Look in the fine print on the can and it is either enamel or laquer/acrylic laquer. Government has no resources to police this or any other of our laws to protect consumers. Get with a reputable auto restorer for your questions.

Paint can was long gone I'm guessing around 35 years ago. This was obviously not original paint job.

Stephen Newell · Jan 22, 2012

Zinc cromate primer is a protective coating for rust however even galvanized steel will eventually rust. It's just run it course. I would expect today's epoxy primers would give better protection.

El Toro · Jan 23, 2012

I used the acid wash paint on a set of wheel weights for my garden tractor. That was more than 35 years ago and I never put a top coat over the primer. I have a picture of them somewhere here on the computer before I use a wire brush on them and reprimed and painted them. Hal

El Toro · Jan 23, 2012

Here are those wheel weights with just acid primer that were painted in the 1970's. I repainted them with an epoxy primer and acrylic enamel. Hal

Rust under paint

showcrop

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CNKS

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RandyB(MI)

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showcrop

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Stephen Newell

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El Toro

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El Toro

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