I just recently started melting lead and before today I have melted about 70 pounds. As the day went on my ingots started to get a foggy color and start to have a yellow brown color to them. Does anyone know what I was doing wrong this time or was it in the lead I had? All of my lead was bought on Facebook. The first 4 ingots I made came out perfect and by the last ingots of the day (about the 16th one) they were foggy and had a yellow or brown tint on them. Any advice to what caused the foggy and yellow color would be appreciated. I use a RCBS 4 1 pound ingot mold.