New Small Portable Cupola!
We have four cupola furnaces of various sizes, the largest being 16 inch bore. Our new smaller 7 in. bore furnace is fitted with wheels and is completely portable. Cupolas are continous melters, with the charges of metal melted in layers alternating with layers of replacement fuel, usually coke. There are no expensive crucibles to worry with. The molten metal is accumulated in the base of the furnace and tapped into homemade ladles as needed. The 10 inch Marshall furnace is capable of approx. 20 to 25 lbs. of grey iron every 5 minutes or about 40 to 45 lbs. of bronze every 6 minutes. Heats of several hours or more are possible, so it is obvious that these furnaces are capable of producing vast amounts of metal for their size and cost. The 10 inch furnace costs less than $200. US to build and the blast can be provided by a large shop vac. One man can easily operate it alone. If you are interested in building one, there is more information on our foundry page for ordering our book, BUILDING SMALL CUPOLA FURNACES and a companion CD with tons of colour photos, CAD drawings, and much more.
Tapping a ladle of cast iron in a 7 in. bore Cupola.
Pouring a 9 lb. Iron Casting with 7 in. Cupola in background.
Stewart
Marshall