Bronze Casting Furnace: NEW JAN.2000.

Bronze Casting Furnace:
New Updated Article.

Derek Kerslake
©April, 2000.

Dimensional diagram of furnace.
Drawing showing correct burner placement.

Bronze Casting Furnace

Derek Kerslale
©June, 1997.

Side view of a small bronze casting furnace.

steel base on casters
furnace body (with crucible and support inside)
lid
support brick for the propane burner.

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Top view of the furnace

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Note how the fire bricks have been beveled to form a cylinder. Fire bricks can be cut with a wood saw or band saw.

"A" marks the hole for the burner. You can see the port is cut tangent to the furnace wall; The flames must swirl around the crucible before exiting through the flue hole in the lid.

Mortar is optional, but if you do use mortar be sure it is designed to withstand 2000 degrees Fahrenheit. Two bands of plumber's strapping - (not shown) are bolted around the furnace for strength.

The furnace floor is also fire brick. Lay them flat on a 1/4 inch thick steel plate. Place the furnace cylinder onto the floor bricks and shape the floor to match the outer wall.

Cut the lid like the base. Bend two aluminium semi-circles to fit the lid as shown. (1/8 x 2 in.stock) Note how bolts act as clamps, squeezing the bricks together. Here, mortar would be a good idea but it is not essential. The top surface is coated with paste as described below. Finally, a hole is cut for the flue the approximate diameter of your largest crucible. The ends of the aluminium semi-circles serve as handles, but remember to use heat proof mitts when removing the lid.

A paste of kaolin clay, vermiculite and water about 1/4 inch thick, is trawled over the exterior; It should cover the walls, copper strapping and the outer edge of the furnace floor.

The furnace must be allowed to air dry before firing. Heat the furnace slowly the first time to minimize cracking of the kaolin paste.

Derek Kerslake

Acknowledgements:
I would like to thank Bill Epp, a bronze sculptor in Saskatoon, Saskatchewan, Canada for his kind advice on the plaster investment process. I hope the publications I offer on the internet can help others the way Bill Epp helped me.
DK.

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