Using lead to fill trim holes

The panel needs to be VERY clean and prepped with lead flux. You should get the panel evenly heated, this will help prevent too much warping. Lead melts at around 750* depending on the tin content. You'll want to be able to work the lead on the panel, too cold and you'll have a blob that will fall off. It was used in the older cars, a production line slather job. You have to get a feel for it so practice on some old steel. I used to work for Verizon, we had lead sheath cable and used lead sleeves to repair damaged sections of cable. Bin thar dun thet!