As I mentioned in our last post, some of us visited the Valley Bronze Foundry during the Cruiser Rendezvous. We were treated to an interesting tour that featured a description of the process of making a Bronze figure. I found the complicated process fascinating, and decided to attempt to describe it here. (All omission and errors will be mine.)
A rough outline of the steps is something like the following, keyed to the photos.
A. The object to be rendered in bronze is encased in a plaster-like material in order to form a “negative” cast of the object. The object itself would have been provided by the artist, not the foundry. The object is removed from the cast, and the cast is put back together.
B. The hollow cast is filled with molten wax which then hardens to form a “positive” image of the original figure.
C. The cast is removed, and the wax figure is “touched up”, removing seam lines and imperfections.
D. Additional wax columns are attached to the figure, as well as is a base. (The space occupied by the columns will become passages for moving molten bronze in and air and wax out of the figure.)
E. The resulting figure is repeatedly alternately dipped into a special liquid and a special powder. The result is a cast that can withstand the heat of molten bronze.
F. The cast-encased assemblage is placing in an oven in order to evacuate all of the wax.
G. The now-hollow cast is placed “upside down” on a frame with the base up in order to receive the bronze. (Not pictured.)
H. Bronze ingots are melted in an electric furnace.
I. Wearing insulating coats and helmets …
J. … using cranes, the molten bronze is put into a vessel to be used for pouring …
K. … and multiple workers use hand-held “arms” to pour the bronze into the cast.
L. The result is placed in a special enclosure to slowly cool. (Not pictured.)
M. The cast is removed and the material from the cast is recovered.
N. Imperfections in the bronze figure are repaired. If the figure was complicated and required multiple casts, then the parts are welded together.
O. Some figures are painted or glazed by an expert colorist.
P. Several example of completed works.