[steve]

Are you guys gonna tell me the best way to get all this stuff off my car is to use a razor blade one section at a time ? When I use my angle grinder it makes a complete mess ! Any better solutions ?

[400 4spd.]

As you found, forget the grinder. All you will do is ruin expensive grinding discs. Razor blades? Not on undercoating!
There are many ways to remove undercoating, but the easiest way I've found is to use a large, soft flame on a torch (vs. a hot, intense flame) and heat the back side of the part. Undercoating will turn loose and can be scraped easily, plus no burning mess. This works great on floor pans if you don't mind the opposite side getting blackened by the torch. Not good for outer panels as you may warp the thinner metal.

[gtome]

We do full frame off restos and have found no better way than what 400 mentioned. Soft heat and a paint scraper. I personally wouldnt be too worried anout that heat warping a panel. All you have to do it warm it up and it peels right off. Crappy messy job, but it has to be done.

[steve]

So can I do this with a simple propane torch and the right attachment ? You know one of those liter sized canisters with a burner screwed on the top.

[400 4spd.]

Yep! Gradually heat an area about a foot square or less. No need for it to get cherry red, just warmed up. When the undercoating is warm enough it will change color or lightly smoke. Wearing leather gloves, start scraping. WARNING!! Hot undercoating on your skin will mean no skin by the time it is removed!

[steve]

Thanks guys. Now I have a new game plan ! Gonna be less messy than throwing bits of undercoating around the garage with the grinder for sure.

And I can't stand finding those wire fibers from the wire wheels stuck in my socks when I run out to get the mail. They get everywhere so the less I use the grinder the better !

[Birdguy]

What worked very well for me was to use a heat gun to soften the undercoating and then scrape it off with a 1" paint scraper. Since there is no flame you don't have to worry about setting the place on fire, but it softens everything up to be easily removed. The gun does get up to 800 degrees so you still have to be mindful of what your doing.

[Icefan71]

You can also try Napa adhesive remover for whatever is left after heating/scraping.

[gtome]

If you use a flame, you may want to consider a respirator. Cant be great breathing that stuff.

[Old Bird]

I used the heat and scraper then took thinner and scotch brite pads to loosen the residue.When it is thinned out and broke loose take some old rags and wipe away the rest. Will look brand new when done.

[gtome]

We usually just blast the bottoms once we get most of the undercoating off. But I know that isnt possible for everyone.

[jamesn]

I finally finished cleaning the undercoating from one wheel well yesterday.
It was such a pain in the *** job that I've been doing it a little at a time. I tried a wire wheel - it removed some and smeared some, messy.
grinding wheel - waste of time, it removed some, smeared some, damaged sheet metal, was very slow.
Aircraft paint remover - smelly, nasty, needs several applications.
Heat and scraper - the best of the above but slow, smelly, sticky gunk, lots of fumes.
Sand blasting - Takes forever to eat through the thick stuff.

And then a miracle happened. Please forgive me, but I bought a cheapo tool from the evil HF place. Yes, I wore a disguise and went there. Told them my wife sent me and purchased a needle scaler, the cheapest one - around 30 bucks.
I connected it to an air hose, climbed under the wheel well and let'r rip. The thing is really loud but the chunks were flying. I had to stop after five minutes to shovel up the crap that was all around me. It chips it off in chunks. Some of it required a little effort but most of it came off easily.

I did more in fifteen minutes with the needle scaler than I did in a couple hours with all of the other methods. Maybe it won't work for every one but in my case it was the right tool for that job. The wheel well is clean enough now so that I can do a final cleanup with the sand blaster. I'm impressed.

[mrennie]

Originally Posted by Birdguy

What worked very well for me was to use a heat gun to soften the undercoating and then scrape it off with a 1" paint scraper. Since there is no flame you don't have to worry about setting the place on fire, but it softens everything up to be easily removed. The gun does get up to 800 degrees so you still have to be mindful of what your doing.

I did the same thing, and doing it on a rotisserie with a case of beer nearby and your favorite music blaring away in the background almost makes it enjoyable...

I then went over the entire floor with a wire brush on a grinder to remove any small spots the scraper missed, then followed that with a good wipe down with wax & grease remover.

[sts]

<a needle scaler>

Dat wood bee dee cat'sass! That one is going into my notebook. Excellent tech advice!

[indymanjoe]

Pay someone..LOL seriously,im doing mine now and its a B***h.heat gun and scrapper so far have been the best.followed by break cleaner,scotch brite pad and lots and lots of rags.Have fun!

[GOAT WHORE]

Originally Posted by indymanjoe

Pay someone..LOL

That's what a lot of guys do with me, they pay me to soda blast it off. I usually try to scrape off anything that will come off easy, then blast away. Funny thing is that nasty old thick undercoating is often the easiest stuff too blast off, go figure!

[Bet Winner]

A propane torch works much better for me than a heat gun. My undercoating was applied at the dealer before the car was sold.

I tried all kinds of chemical/spray on methods--didn't work.

[steve]

Sounds like there is no really easy way that's cheap. I'll just break out the beer and elbow grease ! Thanks for all the tips.

[pontiac1981]

The best and fastest thing i've used is a 2" paint brush and a small cantainer of gas and a 1 1/2" scraper. the gas melts the under coating and it scrapes off easy then i used a gas soaked rag and wiped the area down. the work area needs to be very well vented or move the car out side. I did fender wells, frame, control arms, core support and firewall in a few short evenings.

[drtracer58]

E-Z OFF Oven Cleaner .....