greaser49

I have a 55 chevy that is built right and done, BUT they didnt remove the old nasty factory undercoating.
I could use heat, but that would mean removing the finished interior and othe things. I remember years
ago that there was either a spray can or a super duty paint brush type that would make it all but fall off.
Now I can't find any such thing in the auto supply stores or magazines.
Can ANYONE help me out at all??
Thanks in advance