This is a metal-melting furnace that I built using a recycled propane tank and oil burner. The propane tank was carefully drained of any remaining gas and coated with a thick refractory lining (made from a sand/plaster slurry).
The furnace can reach temperatures of approximately 1,750 degrees Fahrenheit and is capable of quickly and efficiently melting most common non-ferrous casting metals (aluminum, brass, bronze, copper). I am currently using this furnace to cast aluminum parts for building my own lathe and milling machine.
One drawback I have noticed with this design is unequal heat distribution in the fire chamber. The crucible (made of either graphite or stone) is subjected to intense heat on one side, while the other side faces away from the flame. This results in structural cracking and failure of the crucible due to overheating. To improve crucible lifespan, I plan on changing the design of my furnace.
A glowing orange brick demonstrates the high temperatures my furnace reaches in just 10 minutes. The brick was placed on the bottom of the fire chamber for a graphite crucible to rest on.
