My brother (mostly) and I built this used motor oil foundry out of a hot water tank, fan blower,water nozzle, 2L pop bottles and and a small air compressor.
We are very happy how it has turned out so far but In the video you can see a lot of heat escaping. That's because we haven't insulate the tank yet.
In the video you can also see that the bars have what looks like holes in the bottom of them. This is caused from the anti-stick coating on the bottom of the tray. all of the other bars didn't have any signs of this because the coating had burned completely off with the first two bars.