Chemical to remove factory undercoat

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Dave Whittick
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Chemical to remove factory undercoat

#1 Post by Dave Whittick »

I’ve got the majority of undercoating and factory seam sealer removed from the car but I have a few areas where I can’t get the last little bit stripped because of the awkward angles. Can anybody suggest a chemical stripper to help get the last little bit? Lacquer thinner is working to soften it a little bit hoping to hear other recommendations.

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John Brooks
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Re: Chemical to remove factory undercoat

#2 Post by John Brooks »

Depending on how far apart the car is, I have used a cutting torch and lots of oxygen to blow it off. But be careful you don't burn down the project. I do small sections, heat, blast, remove let cool, then repeat. It smokes, stinks and not fun, but is effective. Then wire brush the seam after burning. Small flame, big oxygen. The old white OEM stuff stinks, and will sustain a flame, a putty knife to scrape of any thick stuff helps. Be careful and go slow. An observer to insure you don't get a fire is also good. I have done this for years, I am careful or lucky. A spray bottle with water set on "mist" to cool it down if required.

The acetylene flame melts the goo, the extra oxygen turns it to ash, be quick no need to heat the metal, just burn off the undercoat and seam sealer residue.

I would recommend using the 3M self leveling seam sealer as a replacement before prime and paint. The sealer is thin enough to flow into areas you can't see, sets is 30 minutes and stays semi flexable. You need a $50.00 squeeze gun for the cartridge and some mixpac nozzles, but it is good stuff. Do all the pinch welds under the car with it also. It can also be brushed over after it is on the car. It's a two part system, a double tube, with a shrill nozzle to mix it as its is appled.
John Brooks

62 Roadster
66 912
84 Cab
getting pushed around in porsches since 1965

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Doug McDonnell
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Re: Chemical to remove factory undercoat

#3 Post by Doug McDonnell »

Has anyone ever determined through analysis if the factory undercoating contained asbestos?
1965 356C 2000 BMW 740i Sport 1967 Honda CL77 There is never enough time to do it right, but always enough time to do it over.

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