undercoating removal
 

I am about to start removing the undercoating from my rear wheel wells and could use some advice on what works best to remove the undercoating.

I use a propane torch and putty knife. Heat it just enough to soften it. Make sure the gas tank is out of the car.

Don

I've heard of people using a needle scaler to.

did the whole underside of my car a few yrs back.after 40 + yrs it was kinda dried out so i chipped away most of it with putty knives and chisels.finished it of with wire brushes and heavy scotch bite discs.i epoxied it and rhino lined it in the end. be prepared to buy a lot of elbow grease.

I had really good luck using a gasket scraper. It was so old and dried it just chipped off. I've tried it before with heating it and in some ways it was harder to do.

I don't know how you feel about chemicals but a high grade paint degreaser works really good. A lot of the old undercoating is tar based and melts when you spray a little degreaser or lacquer thinner on it. Go over it with a red scotch brite while its wet and you'll get it really clean without putting a bunch of unnecessary scratches in the metal from a scraper. The key is keeping the solvent from evaporating while your doing it.

Heat gun and scrapers...........sucks to be you! :mock: :D

Depending on age and material type and electric drill motor with a medium wire wheel can be useful.

If its factory undercoating that is hard and thick a small reciprocating saw with a wide blade with the end of the blade cut flat works well. Once you get under it it breaks off clean and in chunks. Should be paint under that.

If it the new rubberized stuff, chemical methods above work well.

What Don said.... and this is assuming the car is stripped of interior etc... in other words -- you're down to a bare body. It's also well worth doing this on a body rotisserie! Then you can stand - the crap doesn't get on you - and when you get low on the body you just sit on a 5 gallon home depot bucket and work away. You'll need a few different sized scrapers - and sometimes the more flexible ones work and sometimes you need them a bit stiffer -- so beg or borrow or buy some different versions. I take them to the Burr King and take the sharp corners off them so they don't dig in to the metal.

Make sure you have a couple fire extinguishers right there at your feet -- or use a 5 and have a couple rags in it with water because sometimes the tar stuff catches fire a little bit.

You just heat a small area at a time and scrape away. Seems daunting - but it doesn't take all that long and is really satisfying when you get all that nasty old stuff off.

Also helps if you bribe your friends with beer... :superhack:

Thanks everybody for the suggestions, I tried a spot yesterday and it is still real pliable so I will probably hit it 1 hour a night and see how it goes. Greg, the beer sounds like a good idea when can you get here! :cheers:

You never know what you are going to find under that undercoating. Here is what I found under the factory undercoat of a friend's 68 Charger R/T once I removed it. The trunk floor was a completely different story thanks to a leaky back window.

Don

like a time capsule.

A friend had a guy come out and blasted the entire undercarriage with dry ice!

Worked fantastic!!!

http://www.dryiceinfo.com/cleaning.htm

All the ideas mentioned are proven, nobody has mentioned oven cleaner yet. :disgusted:
The stuff is toxic and nasty but usually gets mentioned when undercoating removal is brought up. It works, but you do not want that junk dripping on your tender parts. ( We are made primarily of tender parts when it comes to things intended to dissolve charred organics. )

I used it up in my rear wheelwells and the stuff wiped out like melted butter compared to smearing, melting and genereally gumming up with wire wheel efforts.
:whenitsdone:

:popcorn2:

interesting. disco ball and laser lights included?

using an acid product doing overhead work is never a good idea. plus acids will leach out and cause rusting.

Fairly true, working with any chemicals overhead really... The main ingredient that gives oven cleaner it's action is Lye, or Sodium Hydroxide which is on the other end of the PH scale from acid, as one of the stronger bases coming in at 13 on a scale of 0 (Acid) to 14 (Base). Anything on the far ends away from 7 will get your attention on bare skin.

I can see your point, it wouldn't be something to take lightly and maybe I shouldn't have brought it up. As someone else mentioned elbow grease is an alternative. :underchair:

With old dried out under coating, I have found using a air chisel with the pressure turned down works wonders. Just round off the corners of the chisel first!!!

I got about 80% of the undercoating out with a couple of putty knife's. One was pretty rigid and one had some flex to it. I found a few surprises but they will get cut out when the mini-tubs go in. I will get some 3M pads tomorrow for the grinder and get the remainder of it. It was a lot easier than I thought. :thumbsup:

once you get under it it does come of easily. Honestly I stopped using chemicals years ago. Strippers too. With my little reciprocating saw maybe 30 mins each side to go to bare metal.

Its a messy job, I wore goggles and had to lay under the car to do it, plus the rear end is still in the car which is another obstacle.

I put mine on a lift, wore a poncho and used a pressure washer. Stripped it clean. I think I used a 25 degree tip. took about 45 minutes to do the whole underside. You will get wet!!

The tricky part with under coating is the mess you have to clean up afterward. When it cold you can chip it off better. We usually mount the body on the rotisserie and turn it up side down and coat the hard to get under coating with diesel fuel and let it sit and scrap it off a little while later. We do it over a cheap tarp we can later throw away. Then send it out to get blasted in the hard to get areas. Seems to be about the most time sensitive manner we have found. Pressure washer seemed to make a whole other mess that now has to be cleaned up.

I have done a car on a 4 post hoist outside. Blue tarps all over the ground. Spray bottom of car with diesel or other petroleum based solvent them used a high pressure steam cleaner. Looked beautiful in a couple hours. Then throw away the tarps.

Yeah!?!?!? But what did you look like??? LOL