When I got into casting, I realized I needed something to render lead. My friend had a genuine plumbers furnace, which was great, but I looked around and decided i had enough scrap iron to build one. The frame is a piece of Jr Channel with legs welded to it, the burner is from an RV water heater. The pot itself is 6.5" pipe with 1/2" plate welded to the bottom, and round stock welded to the sides so it can pivot/pour. I don't let it fill all the way up, and generally get about 70# per pour, leaving some to get the next batch melting.