Undercoationg removal

[kcbugeye1275]

I've been told you can remove undercoating if you can lay pellets of dry ice on it and cover with a blanket, that it will pop off. Anybody tried it?

 

[tosoutherncars]

Err... is the car upside-down in this scenario? Sounds overly complicated to me.

Is your undercoating wax-based or rubber-based? I have found a sharp chisel to be the best solution for a complete stripdown, accompanied by a heat gun in the case of rubberized undercoat. Followed, in either case, by a wire rotary brush. (see the VW in my sig for lots of floor work!)

A nice cold beer and some good tunes make this a slightly less miserable task, but it's certainly not fun!

 

[kcbugeye1275]

My bugeye that I've had for about 25 yrs has had undercoating on the under side of the bonnet. This winters project has spruced nearly everything else up and now I'd like to remove the undercoating and paint it. I stripped the paint and nearly all the bondo (on the outside) yesterday and now I'm looking at the best way to remove the undercoating. I'm thinking that a couple blankets in the yard and I'll try the dry ice if no one can tell me a reason not to. I have no idea about the type of undercoating except its at least 25 yrs on and it is still well adhered.

 

[mrstinson]

The dry ice may make the bonnet very brittle. I would try the chisel and heat gun first.

 

[Speedy_Pete]

Use a wallpaper scraper instead of the chisel, much quicker.

 

[Hap Waldrop]

Is your undercoating wax-based or rubber-based? I have found a sharp chisel to be the best solution for a complete stripdown, accompanied by a heat gun in the case of rubberized undercoat. Followed, in either case, by a wire rotary brush.

That's what I do as well, dr ice will work on some stuff, but not the rubber/tar based stuff. Here's a photo of 67 MGB GT we're working on right now and doing as described above, it going to a rally car and ran in the LeCarrera Panamerican road race in Mexico, it basicly a hot rod street car with a stripped interior and all the race car safety equipment, roll cage, fuel cell, racing harnesses and seat, etc.. So the idea is to get the tar crap off so it can be primered and have a slick paint job inside , since it will have no carpeting on interior upolstry.

 

[Atrus]

I har tar-like stuff in the engine bay. several cans of brake cleaner, a tooth brush for tight spots, and a small metal putty knife took care of that!

 

[regularman]

I cleaned the bottom of mine down to the original primer, or if I came to the original BL undercoat in good condition and not near any place I was going to weld, I left it. The best thing I found to remove undercoat was using one of those little radiant heaters that screws onto a gas bottle. Put it on the backside and it will heat up about a 12"x 12" area, once hot, I used a brass scraper to remove it, then wipe whole thing down with laquer thinner when done to remove anything that is left, be sure and turn off the heater first though. You have to pick up one end of the car to use this method.