93EXCivic
93EXCivic MegaDork
1/8/13 12:51 p.m.

What is the best way to remove undercoating from a car? The car in question is a Yugo.

JohnyHachi6
JohnyHachi6 HalfDork
1/8/13 12:56 p.m.

If you had a way to hold some dry ice against it or spray liquid nitrogen at it, the coating will become very brittle and you can easily break it off by tapping it with a hammer. Best alternative I can think of0 is a beefy wire wheel on a grinder.

oldtin
oldtin UltraDork
1/8/13 1:12 p.m.

I've done it with dry ice and torch and scraper. Dry ice is nice on horizontal surfaces. On vertical surfaces it doesn't work so well (rotisserie?). Torch and scraper sucks laying on your back with hot tar dropping on you (actually just heat a patch enough to loosen it up). Took a couple of days to get it all off the TR4. It came off the mg easier. My old 2002 had the nastiest/stickiest. Wire wheels just kinda melt it and spread it around - then you can clean it up with solvent. Dry ice is best at preserving paint. Heat and scraper - unless you're a whole lot more careful than me, you'll get a few scrapes.

yamaha
yamaha SuperDork
1/8/13 2:52 p.m.

I did torch/scraper method......then aircraft paint remover to get the remaining residue off

44Dwarf
44Dwarf SuperDork
1/8/13 2:56 p.m.

remove running gear, wiring, interior, glass.....add 1/2 cup of gas then toss matches at it.....

Carl Heideman
Carl Heideman
1/8/13 2:57 p.m.

If you warm the opposite side of the panel with a propane torch or even a heat gun and scrape the undercoating, it usually comes off in very nice sheets. If you heat the undercoating directly with the torch, it tends to catch fire and get very gooey and clog up your scraper. So, try heating the backside if you can get to it.

--Carl

p.s. Be ready for fire and fumes, so play extra safe

Raze
Raze SuperDork
1/8/13 3:06 p.m.

air chisel set on low PSI, just make sure the chisel is actually sort of sharp...

fasted58
fasted58 UberDork
1/8/13 3:57 p.m.
yamaha wrote: I did torch/scraper method......then aircraft paint remover to get the remaining residue off

^ been using this method, works for me

jpnovak
jpnovak New Reader
1/8/13 4:48 p.m.

Get one of those cheap vibratory oscillating tools from HF. Use the flat scraper blade. Much faster and cleaner than the wire brush in a grinder method and no fumes like the torch method.

I stripped my 914 with this method. For example, the floor took about 45 minutes. Previously this would have taken about 4-5 hours with the grinder and knotted wire brush. Then another hour with a vacuum cleaner cleaning it all up.

Example of Undercoating Removal

ransom
ransom SuperDork
1/8/13 4:54 p.m.

In reply to jpnovak:

That is the most awesome thing I've heard lately! Thanks!

Toyman01
Toyman01 PowerDork
1/8/13 5:13 p.m.

I liked the looks of these to use in a sawzall. I've never used them, but they look like they could berkeley some stuff up.

poopshovel
poopshovel UltimaDork
1/8/13 7:04 p.m.

Yugo??? Invite 3 friends over. Get drunk. Flip car over, setting bumpers on sawhorses (or not.) Apply dry ice. Chip away. I used the air chisel method for sound deadening till I saw the dry ice in action.

erohslc
erohslc HalfDork
1/8/13 7:43 p.m.

Also, depending on the formulation, common mineral spirits may dissolve whatever is left. Brush or spray it on, use a stiff bristle brush.

Swank Force One
Swank Force One MegaDork
1/8/13 8:07 p.m.

Are we all talking about undercoating? Sounds like at least one or two of you are talking about sound deadening.

How much weight could one expect to lose by doing this on a normal sized car? And is this legal for street mod autocross classes?

moparman76_69
moparman76_69 HalfDork
1/8/13 8:12 p.m.
erohslc wrote: Also, depending on the formulation, common mineral spirits may dissolve whatever is left. Brush or spray it on, use a stiff bristle brush.

I was going to suggest kerosene.

oldtin
oldtin UltraDork
1/8/13 8:35 p.m.

In old brit cars there isn't much difference in undercoating and sound deadening. Cutting out panels with undercoating on them and putting in new metal is another way to go

Trans_Maro
Trans_Maro SuperDork
1/8/13 8:37 p.m.
Toyman01 wrote: I liked the looks of these to use in a sawzall. I've never used them, but they look like they could berkeley some stuff up.

Yup, they'll berkeley your sawzall good.

I made lots of money off glass installers and tile guys who used those scrapers.

Shawn

Kenny_McCormic
Kenny_McCormic HalfDork
1/9/13 1:43 a.m.

The undercoat on a Yugo is some tough as nails PVC stuff, at least on my 88. I would leave it alone if there is not rust that needs dealt with. The sound deadening inside is just standard tarboad, comes off easy at this age.

93EXCivic
93EXCivic MegaDork
1/9/13 7:18 a.m.
Kenny_McCormic wrote: The undercoat on a Yugo is some tough as nails PVC stuff, at least on my 88. I would leave it alone if there is not rust that needs dealt with. The sound deadening inside is just standard tarboad, comes off easy at this age.

I am removing it to get at rust.

93EXCivic
93EXCivic MegaDork
1/9/13 7:20 a.m.
jpnovak wrote: Get one of those cheap vibratory oscillating tools from HF. Use the flat scraper blade. Much faster and cleaner than the wire brush in a grinder method and no fumes like the torch method. I stripped my 914 with this method. For example, the floor took about 45 minutes. Previously this would have taken about 4-5 hours with the grinder and knotted wire brush. Then another hour with a vacuum cleaner cleaning it all up. Example of Undercoating Removal

Thanks. I have one of those.

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