Potter putty
 

I have been trying to cut out my in floor livewell with not much luck.. I was able to only get half of the well out... I do believe this stuff would survive a f7 tornado and a cat 12 hurricane..i actually gave up after 5 hours trying to remove the darn thing

The stuff after 40 years still bonds well to be so old. The best thing that I found to get it loose is to chisel it away with a hammer and cold chisel. It is so hard it's brittle.

Yup,a hammer and extra long shanked chisel is what I had to use to break up the gobs of "potter putty" they had used in the rear of the fuel tank and floor live well in my Tsunami.

I couldn't believe how difficult it was to break it up.That stuff was like concrete.I had to do most of it by feel as it was an area where I couldn't see,and I was beginning to wonder if I was just hitting solid fiberglass.
Finally,a big chunk busted free and I was able to get 75 percent of it out.

When I worry about the secondary bond strength of polyester based products,I just think back to the "potter putty" and my worries dissapear.

If you have a good compressor available, get one of these:

http://www.harborfreight.com/medium-...sel-69866.html

You know why did i not think of that.. I just kept thinking this stuff will give sooner or later.. I will be using my air chisel next