I was going to use a pipe fitting that I fond in my garage to make a bowl, but I don't know what it is made of, it's like a dark gray, and it sticks to a magnet, an I'm not sure what it's made of, do you think it would be ok to use to make a bowl out of, and would it be safe to smoke out of it? How do I know if it's like lead or something that I can't smoke out of?