anchorbarbronze .com

The process begins with the artist's original piece sculpted in clay, wax, wood or other material. First a mold is created of the artist's original model, a soft clay is used to cover the model, and then build a "plaster of paris" cast around the clay. Dams are created so the cast may be separated after it has hardened.
This picture shows an artisan breaking open the plaster cast by driving a wedge between the two halves she created with the dams.

As the plaster cast is opened, the clay covering the model is revealed. Determining where the plaster cast will come apart and how thick a blanket of clay to use, takes knowledge and experience.
The reason for the clay layer is to create a space for the rubber to flow when the mold is created.

Once a mold is created, a wax pattern can be made by pouring hot wax into the mold. In the picture below the artisan is preparing to open the mold and reveal the wax pattern.

In this picture, you can see the plaster shell, the rubber mold and the wax pattern. The wax pattern will move on to the next stage of the process.
This piece has several additional smaller parts that have been molded separately. Depending on the size and complexity of the sculpture, the number of pieces and the work involved in assembly can vary greatly.

Here the wax pattern has been removed from the mold. From this point, the wax pattern moves to the chasing and sprueing section of the foundry.

Here you can see the other pieces that have been created in a different mold. These pieces will be assembled after the sculpture has been poured.

Each part must be chased to have the extraneous wax bits carefully removed and and be prepared for the investment process

The chased and sprued wax is ready for the next step called investment.
Since the wax model will become the bronze, a great deal of care is taken to achieve the highest possible detail and faithfulness to the original sculpture.

The chased and sprued wax piece is dipped into a vat of silica slurry and set to dry. The artisans will build this shell up by mixing the slurry with several grades of sand, from very fine to coarse.

In this photo the artisan is pouring the finest grade of sand over the still tacky silica coating. This process will be repeated until the finest details are covered with a solid layer of shell.

After the first layer is completed, the piece goes to a coarser grade of sand that will build up a thicker shell. Here you see the piece with the first shell completed.

The picture below shows the completed investment with all the layers of sand and ceramic being air dried. The investment process takes time to do properly. The more carefully this step is completed, the better the result in the pour.

Once the investment is dry it is bound and grouped with a number of other invested pieces. They are stacked in the furnace and heated to 1600°F. The wax melts and runs out at the bottom of the investment. What is left behind is an empty shell with the details of the sculpture.

The shells are removed from the oven and placed in a tub full of sand. The crucible is removed from the furnace and moved to the location of the shells. The bronze is poured into the shells.

The pour must be carefully handled. The temperature of the molten bronze is critical to a successful pour. The artisan must control the speed of the pour in order to maintain a high quality bronze without defects.

After the bronze is poured and allowed to cool, the investment shell can be broken away. This is hard dusty work for the artisan. The ceramic shell is very brittle but also very hard.

Here is the piece after most of the investment has been broken away. At this point the work moves to another area where artisans will carefully blast off the remaining investment and prepare the bronze for welding and chasing.

Now the work is ready for assembly. The bronze is polished and cleaned up so that the parts can be welded to the main body.

Assembling the parts, welding and grinding the piece is the part where the artisan's knowledge and experience is crucial. The artisan works closely with the artist to make certain that the piece is correct.

The additional parts of the sculpture are welded to the main body helping to restore the detail of the original piece. A high level of skill and patience is required in order to assure quality in the assembly.

Assembly complete, the final step is patina. Patina involves putting a finish on the bronze.

Here, the patina is being applied. The artisan works with a brush and a small torch to apply the patina and oxidize the bronze.

The patina process involves painting on a layer of chemicals and then applying heat. Using different minerals creates different colored patinas.

Another picture of our casting during patination. Using different chemicals in different combinations and strengths results in the creation of different colored patinas.

As the artisan works on the patina, the sculpture's details come to life. A great deal of knowledge and experience are required in order to produce the best patinas.

The completed work on a walnut base with the name plaque installed.