Way back when our Hamb era cars were new, it was common practice to get them undercoated with that nasty asphalt based undercoating which was poorly applied since no one removed anything in the way and just sprayed so that it would look like it was helping prevent corrosion. Anyhow, we are now stuck with the problem of how to work on these cars. My latest attempt is to soften it with a torch and then attack it with a putty knife which seems to work except in the hard to get at crevices. Do any of you guys know of a decent solvent that would help?
I’ve found if you heat the area that’s already s****ed off, a rag with solvent will easily clean off the remaining tar. For stubborn areas a wire brush also works pretty good.
The stuff on my Nomad, came off in chunks using an air chisel with broad blade. Didn't get it all, but a good portion.
Used gasoline on mine, to get the remains off after the torch/putty knife routine. (it makes it easier if you cut part of the car out before doing this, so you can work on it right side up)
You didn't put your location in your profile but see if there is a Dry Ice cleaning company in the area. Works well cleaning many applications. Industrial Mfg's who use Cold Jet Dry Ice machines for spraying Dry Ice at a decent pressure for removing buildup of plastic and rubber build up on injection molds. It doesn't hurt the metal. It just instant freezes the coating so it blows off. Could be quicker and more efficient, costs could vary.
Yes, dry ice !. Cold not hot is the answer. I have a thread on here somewhere found it. https://www.jalopyjournal.com/forum/threads/dreaded-removal-of-old-undercoating.1292358/
Me after s****ping off the entire bottom of my 66 Bel Air wagon 15 years ago. This was with safety gl***es, a mask and about 6 hours work. If I remember correctly, it took 4 rounds in the shower to finally get everything off me. But hey, made for a good photo.
A dry ice blasting business in the Detroit metro area quotes undercoating removal for a complete car starts at 3 k
When welding patchs in to floor of one of my Studys,lomg ago,I removed some of the ****py under tar junk. As pointed out above. Years later,hunted up some "Do-it-your -self undercoating",to use on a oval track stockcar,too cover up some mod.s that may or may not been legal= made it look stock old car. LOL Never found,even after going through tech a doz. times,,,< So it's good for something
Over the years I have found that I could use my air chisel with either a hammer or a chisel bit to remove factory undercoat. I have an air chisel that has a trigger that is variable speed, I mean you can make it putt putt or go full tilt. Somewhere closer to the lower end of that comparison closer to a rattle I would just go over the heavy undercoat and it would literally fall off the car. Only getting as aggressive as needed to make this happen. I’ve found that the undercoat is brittle so it breaks up comes off leaving a clean painted surface that only needs minimal clean up. I’ve used this technique for doing welding or weight reduction in race cars. You should never grind undercoat especially overhead the dust can kill you because it is asbestos! So give it a try with an air chisel, maybe put a regulator on it so you can turn it down and go for it. A full face respirator is the ticket to protecting yourself. Good luck
@milwscruffy That picture belongs in this thread! https://www.jalopyjournal.com/forum/threads/photos-that-tell-a-tale.1347907/
Done ! I failed to mention I did the same thing on my other Bel Air wagon before that and before I had a digital camera. So yes, I'm dumb enough to have done this twice !
Like @squirrel said, elbow grease is the only way. I have some older friends that were into drag racing in a big way back in the 60s. The real serious builder a**** them would s****e all undercoating off every car they built to save weight. His method? Propane torch, various s****ing tools and endless hours on his back.
From 1957 on, when we bought any new car, we got the industrial undercoating spray applied by this company located in Los Angeles. We were advised by our mechanic friend in Los Angeles who knew the owner and had most of his own cars get the industrial application, no the factory spray that looked like from a spray can... The factory undercoating application did nothing to stop the rust from appearing all over the undersides. The only way to stop the rust process was to get the thicker industrial spray on the whole undersides. It not only protected the car undersides, but it actually silenced the muffler sounds through the floorboard and rest of the sprayed on application areas. Hello, By the time we were getting ready to tow the 1940 Willys Coupe we had found in a neighbor’s backyard, we did not want to use a rope like we did with the Model A Coupe and 51 Olds Sedan. That was too shaky, even for two miles of neighborhood streets back to our Westside of Long Beach house. So, we drove the Impala over to our friend who was an expert welder and owned his welding/muffler business. Before we were going to get a trailer hitch put on the Impala, he had to take off the full underbody custom industrial black undercoating we had sprayed on in Los Angeles. The factory spray was minimal to say the least. This separate application was done by a business that coats all sorts of items, including undersides of cars, even those that are new or fairly new. The bottom was cleaned and I watched him spray on this thick black goo all over the places underneath the Impala. Nothing was left, not coated and now, we knew, if we happen to take the Impala to the beach at high tide and the parking lots/low lying highways were over run with salt water, we would be safe. Several times, we took the Impala to the beach for surfing with two longboards coming out of the trunk. The rear seat back was removed to make room for those longboards. Even with the seat back removed, the boards needed a red flag to be legal and safe. When we had to leave the boards and car, we put them nose first all the way to the windshield. We knew the salt water we had to drive through on high tides and into the parking lots that were overrun from larger waves, high tide and low sand berms would do a number on the bottom. But, with the full undercoating, it would be protected. Just in case, my brother took us to the local spray and wash place to hose off the whole undersides of the Impala when we were ready to drive 40 miles back home. Jnaki When I sold the 58 Impala with the latest C&O stick hydro to a young friend, he knew it had the full undercoating as we had put it up on the gas station racks and checked things out. Not one thing was rusty or showing any rust. So, the full spray coating did what was necessary to protect our Impala. Note: Our welder/muffler guy decided he needed various spots to attach his design of the trailer hitch on the the Impala. So, he heated some of it and s****ed it off to leave a clean place to weld. Once that was finished and the trailer hitch was installed, we drove back to the industrial spray company in Los Angeles to get the new metal bracket covered with the thick black undercoating. Now, it was fully protected again. We also had two other cars after we sold the Impala and they both got the same spray from the same undercoating spray company in Los Angeles. The El Camino saw more salt water as it had to cross plenty of small salt water incursions on those empty beaches in Baja Mexico and locally near Camp Pendleton. But, as soon as we could, we stopped at the local spray and wash to get the salt off of any thing including the tires and rims. It kept of our hot rod sedans and the El Camino in perfect condition, despite the 125k miles on the El Camino when sold. Note 2: The El Camino was sold to a young surfer/sailor from Dana Point. He was going to trailer his small sailboat to the ramp in the harbor to launch and retrieve his boat on a weekly basis. He was grateful that I had coated the undersides of the El Camino with industrial grade undercoating process… YRMV
I've used dry ice to freeze it and then chisel it off and used a torch, putty knife, and brake cleaner. Both methods work, but getting and storing dry ice can be a pain in the ****. Car is a bit off-topic - it's a 1972 Alfa Romeo GTV that I bought when stationed in Italy. Took it down to the bare metal, top to bottom, in my garage in Naples.
The magic bullet is money . Paying someone else to do it. There is a dry ice blasting place in Lethbridge.
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