FMD #46

Now that all the pour spouts, sprues and gates are in place on the wax sections of the sculpture to vent the gasses, air it is time to make the outer shell mold. This is just another part of the “lost wax” process in casting for bronze. The wax is the replica of the clay sculpture and needed to be in smaller sections of 24” or less in order to fit inside of the kiln. Now the prepared waxes need to have a ceramic shell built up around the entire wax. The finished shell is very weird and organic looking as it builds up and grows around the works. The photo above is of the bust with the flowered hat….the strange cactus-like arms that reach from the pouring cup (attached to the base and sitting on the ground) up the brim of the hat. 

The wax sections are dipped multiple times in liquid slurry and then dusted with a silica powder and allowed to dry in between dips. This happens 11-15 times creating a coat of dried silica on the wax about 1/4-3/8” thick. You have to let each dip dry completely (hence the large fans and the process takes from one to several weeks to complete.

The following video below is not my own and is not showing the FMD sculpture, but it is of the Art Castings shell room and you can see the process in part. For more information on the process of casting in bronze I  have a page devoted to the creation of “Ascension” that you can view.

The talented crew at Art Castings will continue to build up the shells on all the pieces, letting it dry between coats until the ceramic outer shell is thick enough to withstand the high heat of the kiln, the next step towards bronze.