More scenes from the foundry casting of Memorare, Sand Creek 1864

As I mentioned in Part 1 of this series, I promised one of our clients updates of how his Memorare, Sand Creek 1864 was progressing at the foundry. This has been one of my most popular articles, so without further ado, here are more details of the casting process for you to see:

Lost Wax Casting Method

Although I shared these steps in Foundry Tour I, they are worth repeating so that you can follow which part of the process is depicted in the photos of Memorare, Sand Creek 1864 that follow.

Memorare, like all of my work, is made with the lost wax casting method. This is an ancient practice that involves the following steps:

1. Mold: The foundry makes a mold that has a pliable latex interior and a solid plaster exterior. This is made by encasing my clay sculpture in the mold materials.
2. Wax pour: Hot wax is poured into the finished mold in thin coats until the desired thickness is achieved.
3. Wax removal: The mold is removed from the outside of the hardened wax.
4. Chasing: A heated metal tool is used, by hand, to smooth out any seams or imperfections in the wax.
5. Spruing: The chased wax is affixed with “sprues,” which are branch-like paths on which the molten bronze will flow.
6. Slurry: The sprued wax is dipped in a silica/sand slurry that will harden into a shell-like mold, typically called a ceramic shell, although ceramics are not actually used.
7. Burnout: The ceramic shell with the wax inside is placed into a kilt to both harden the shell and melt out the wax. The foundry then has a perfect mold in which to pour the molten bronze.
8. Testing: The cooled ceramic shell is tested with water to check the venting and feeder tubes created by the sprues. Any defects in the mold are repaired.
9. Pouring: After the shell is finished, molten bronze is carefully poured into the shell. The shell is heated first so that the bronze does not cause it to shatter.
10. Release: Once the bronze has cooled, the shell is sand-blasted away and the now-bronze sprues are cut off.
11. Welding: Parts of the bronze that had been cast separately are welded together.
12. Metal chasing: The bronze is carefully worked by hand to remove any air bubbles, rough edges, or other defects.
13. Patina: The finishing touch occurs when the patina artist, called a patineur, applies the finish of choice to the bronze.

Memorare‘s progress

Memorare, is now almost completely done! The only step left is to add the patina.

Here are the steps the sculpture has undergone to this point:

Release I

In this step, also called “knock-out,” the ceramic shell is broken away in large chunks from the bronze underneath.
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Release II

Here is part of the cast bronze (the arm of the male figure in Memorare) after casting and knock-out. The remaining ceramic shell, visible here as the white areas, will be removed by gentle sandblasting.
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Cast pieces awaiting sprue removal

More pieces of Memorare, Sand Creek 1864 still showing ceramic shell and sprues. Notice the chunks of broken ceramic shell on the floor.
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Cast parts for assembly

This shelf is loaded with separate segments that will be hand-welded together.
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Welding

Assembly of the parts is done by hand by a skilled welder.
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Partial assembly

Getting there…
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Post welding and chasing

This photo shows Memorare, Sand Creek 1864 completely assembled and “chased” (welds and other imperfections ground down and matched to the artist’s original texture).
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Ready for patina

Here it is! Memorare has traveled a long road. The next and final step of the journey will be application of the finish by the skilled patineur artisan.

Stay tuned for our final installment, when we reveal the completed bronze.
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Are you interested in adding Memorare, Sand Creek 1864 to your collection? I am offering a limited number to private collectors. Please contact me for details.