I used a sheet steel muffin tin today to cast ingots in and found that the lead would not release from the molds. It was a recycled used muffin tin. Maybe it had some kind of coating that melted and bonded the lead to the mold. I tried heating the mold some over the burner to see if they would loosen up but no luck. Here is a pic of the end result of separating lead from molds. What was the problem?
Kevin