Flex coat

I just brought home a 12' aluminum john boat from the 1960's (maybe even earlier). Someone had painted over a number of holes that had been shot into it with some of that black wonder compound stuff. Looks like the type they advertise on the TV where they coat a screen door in the bottom of a boat hull and it holds water. Sacrilege!

Any ideas how to easily get rid of it? A heat gun?

Thanks in advance

I had the same issue with a '59 Lone Star.
several kinds of sealants were used..... household caulk,
expanding builders foam, spray seal, flex seal, etc.

you will have to experiment with different heat sources to see what
will work for you..... some of these coatings get harder the longer they sit.
I found the hand-held propane torch, putty knife and wire brush was the best choice. (for me).
working small areas at a time will prevent frustrations.
do not get any area too hot or you will run the risk of warping the metal.
aluminum melts at about 1200*f. the aluminum will warp at about 800*f.
that tar spray seal stuff melts at about 350*f.






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