Removing undercoating

[enjenjo]

I am working on the Mustang hood. For some reason the PO undercoated it. Outside of scraping, is there an easy way to get it off? I have a pressure washer if that helps.

[UGLY OLDS]

What about oven cleaner to soften & then pressure wash   :?:    
Careful ...It will attack the paint .... AND YOU  :!:  

Bob....

[chimp koose]

lay the hood on the floor upside down and pour something in it that softens the undercoat. Maybe paint thinner, solvent , or even coca-cola.When the stuff is good and soft it will probably pressure wash off for the most part.Come to think of it if you get the hood below freezing, you could probably crack the stuff off in big chunks.We get cold enough here that undercoat can crack off even when you dont want it to.

[1800guy]

ATF works well to soften undercoating.  Use a plastic scraper rather than a metal one to lessen scraping damage.  When the easy stuff comes off and leaves tougher stuff behind, use paper towel as a mat to hold more ATF in place.  Rinse and Repeat.

[taxpyer]

Try diesel fuel?

[idrivejunk]

Wax and grease remover like PPG's DX330 and a red Scotch Brite. Wet it with a spray gun. Start with a putty knife if its thick, and work while its wet. If its old enough to be hard, break the surface up with sandpaper or a Clean-n-Strip disc then go for the degreaser and scuff pad. Should melt it right away if its rubberized undercoat. Wear nitrile gloves and eye protection, of course.

[phat46]

When we used to get cars under coated here, to hasten their rusting process, the cleaner they gave us sure smelled like kerosene of diesel fuel. I tried diesel on the under coating and it just wiped off.

[enjenjo]

Lots of good ideas here. I'll try them and let you know my results.

[Ernie Callen]

Removed undercoating of 51 Ford with heat gun and scrapper, residue with kerosene
Ernie

[kb426]

I use a 4" wide razor scraper on anything that is flat. The lumber yard sells those. The handle is around a foot long so sometimes space is a problem. A fresh blade removes lots of things in my world.

[Digger]

A multi tool with vibrating scraper blades makes short work of undercoating.

[enjenjo]

I got it done today. I had a pint or so of Tiki torch fuel, Kerosene, so I used that first. It softened it up pretty good. I scrubbed it in with a brush a couple times, and hit it with the pressure washer with some car wash soap in it. The got about 95 % of it, but I was out of Tiki fuel. I looked around, and found a gallon of CRC 5-56 that I bought in 1971, so I tried some of that, scrubbing it in with a brush, it worked even better because it doesn't evaporate as fast. I power washed that off, and it's ready to sand for paint.

Thanks for the ideas