I am in the process of cutting up a 1940's sailboat keel and it cuts like butter. Some of the softest lead I come across. I have had a keel that had rebar in it. So anything goes in making a keel. Test it. Test it Test it. or find a sinker maker that will take all your lead ( bad decision) you had to have because it looked to good to pass up. I have a guy. LOL