Undercoating Removal Advice

[Weldguy]

I'm ready for the next big step in getting my 1970 Challenger back on the road. I will be welding rear subframe caps because of frame rot and welding frame connectors from US Car Tool that are cut to fit the underbody profile. This will require the removal of both factory undercoating and some rattle can rubberized that I sprayed on in 1982. The metal, of course, must be as clean as possible for welding.

Initially, I thought some paint stripper would work. However, most YouTube videos I've looked at use some source of heat - either a torch or heat gun. What have you found that works the best?

 

[Challenger RTA]

By happenstance I had mine up about 18"-2'. And was scaping, Wait trying to scrape the under coating off, Not going to good. As I laid on the floor and took a breath. I glanced to the side and the 55k btu torpedo heater caught my eye.
Had a 6" elbow and stuck it in. Slid it under and in seconds the undercoating fell off. So I would move every second or two, so the undercoating would not fall into the elbow. What didn't fall off would only have to touch with a scraper.
Under the factory under coating was kind of bright metal with stains of undercoating. So I did a light sand blasting to clean up.
All the interior was out
A second person would make it easer, turning the heater on and off.
My intention was to clean up a little, inspect and preserve.
I got a little carried away. In for a penny in for a pound.

 

[Steve340]

I saw a guy on You Tube removing it with one of those scale remover/needle pin pneumatic gun things.
It looked like it was easy and did a good job.

 

[Deathproofcuda]

I've used heat gun or a propane torch. Scrapes off pretty easily after a little bit of heat.

 

[Weldguy]

Some good ideas! Thank you.
I'm heading out to the shop in a while to try the suggestions.

 

[Daves69]

I might try something such as this in my variable speed reciprocating saw if I were doing it again....................

 

[Xcudame]

X3! Heat is your friend for undercoating removal!

 

[larry4406]

I used a pneumatic scraping tool from Harbor Freight when I had it on rotisserie. Worked well. Wear ear protection.

 

[1moretoy]

Check out my YouTube Video.

 

[chilsam]

heat gun, putty knife, walnut or lock picks...I did my whole underneath

 

[PLUM_72]

I used a variety of tools. For larger flat sections I used an oscillating saw with a scraper blade. I bought a cheap one to do this. A drill with a variety of different wire brushes works too. Then also razor blades, putty knives, etc. I heard yellow easy off oven cleaner works. It didn’t do much for me but make a mess.

 

[mayhem]

Check out my YouTube Video.

Holly crap, your video triggered PTSD from my enlisted years in the Navy chipping superstructure paint and non-skid decking. Seriously, if I had to do an underside, the needle gun would be a strong first consideration. Thanks for posting.

 

[Weldguy]

Holly crap, your video triggered PTSD from my enlisted years in the Navy chipping superstructure paint and non-skid decking. Seriously, if I had to do an underside, the needle gun would be a strong first consideration. Thanks for posting.

Thanks to all for the suggestions. The best combination for me was using a heat gun and the little Harbor Freight pneumatic scraper. I finished curved areas with a wire wheel.