The Stovebolt Site Forums The Shop Area Paint and Body Shop under coat and road tar

What is the easiest way to get road tar and undercoating off fenders or other parts? I have heard that WD-40 sofents it up so you can scrape it off. Is this true or not. I havent done a whole lot of body work. I know the powder coaters use a oven to bring it up slowly for 24 hours then cool it down the same way which causes the undercoating to become briddel and you can just wire brush then. Any ideas fellows?
62Blue
Don

I've never used anything but a torch or heat gun to remove tar/undercoating. Warm it up a little and scrape it off. If you're not worried about the outside finish, apply the heat to the outside of the fender.

Well I tried the WD-40 method last night and let it set over night to soak in to the undercoating. Went out this afternoon and it was a little brittle to soft in spots. It looks like if you would put it in a tank to soak over night it would probability dissolve the undercoating. But I think the cost would be very expensive to do it this way if you had a lot to remove. But it works slow but works.
62Blue
Don

I just wear an old pair of coveralls, a bonnet and face shield, take it to an open area, and use a wire knot wheel on an angle grinder. There is just no clean or easy way to remove this stuff unless you have a lye tank big enough to soak the body in.

Don,
Try brushing on some Diesel fuel......
it's petroleum base dissolves tar and most underbody coatings, yet is still oily enough to stick to the parts you are trying to clean.

DO NOT use Petrol!!!!!!!!!!!....Just Diesel......
or there might be an earth shattering KABOOM!

The heat gun and a paint scaper worked good for me. Peeled right off with no residue, finished it with a wire wheel after that.

I just started removing the old undercoating on my fenders the other day, i used a small air chisel from harbor freight, I just took my time and it came right off, then i sandblasted the old paint off. I learned that just sandblasting won't take it off.