Here's a tip to help keep your bopper together. Right after the lead in the copper bopper has turned solid, take a 1/4" bolt, put the end in the middle of the lead and smack it with a hammer, put a dent about 1/16" to 1/8" deep in the lead. Lead contractes when it cools and will be loose in the copper, after you beat on it a while, the copper can slip. The dent expands the lead so it will be tight in the copper. Also, a lot of glues do not adhere well to copper but the do stick to lead so this makes a more solid bopper. Bill