I have run short of lead ingots so I decided to cast some today since it is cold and windy here in SW MO. I had about 150 # of various scraps (radio active medicine containers,X-Ray room liners, plumbers lead, some wheel weights and a bunch of old pyramid shaped sinkers).
I melted them down with my fish cooker in a cast iron pot. The pot had not been used for at least 10 years when I cast some babbit spoons.
For about the first hour the lead would bubble up in the middle. Once it even errupted and splashed lead on the floor (glad I was outside at the time). Then it settled down and I had no more bubbles. For a while it looked like my wifes early stages of making gravy.
The lead has been in side for 9 years so I haven't a clue as to what made the bubbles.
Any ideas??