This is my foundry furnace being fired for the first time. The fuel is charcoal and is more than capable of melting and casting aluminum.
One the left is an old Kerby vacuum. The speed is controlled via a router speed controller. The air output is feed into a homemade dual valve which allows very precise control of the flow of air into the furnace on the right.

Night firing, well actually this is still the first firing of the furnace, it took about Five hours before it stopped steaming. Also I fired it without a crucible, and had the air cranked up to high, it melted part of the lining!!


Notice the homemade air control valve. The input air provided by exhaust of the old Kirby vacuum is fed into the valve box feeding both valves. The valve closest to the vacuum allows the air to be "dumped". The second valve controls the flow of air to the furnace via the flexable black pipe.

The old vacuum proved to be very loud since it runs at a high RPM. To control that I plugged it into a router varible speed control. These can be found at Homier, Harbor Freight, HomeDepot, most woodworking cats as well as many other places. Got mine at Homier of $10.00. At low speed I can hardly hear it, but provides more than enough air.


The wheels are all plastic but far enough away they never even get warm, even after a long melt.