- The Lost Wax Bronze Casting Process -
This process is very time consuming, laborious and costly.
Small works take approximately 4 to 6 months to create and life size works can take up to a full year when the Foundry is busy.

BRONZE IS AN ALLOY OF 95% COPPER, 4% SILICON, .02% TIN, .02%LEAD, .06% ZINC

STEPS:

1) CREATE - wax sculpture, large sculptures are cast into numerous sections.

2) SPRUE - attach wax gates, vents & pouring cup - which act like plumbing to the work.

3) INVEST - dip in a liquid ceramic slurry to build up numerous layers of a hard refractory mold.

4) BURN-OUT - an autoclave and hot kiln melt the wax out of the hard mold - "lost wax method."

5) POUR - molten bronze is poured in the empty mold at 2100' Fahrenheit.

6) BREAKOUT - once cool the ceramic shell mold is broken away to reveal the bronze sculpture.

7) SANDBLAST - remove the last traces of the ceramic shell mold that adheres to the bronze.

8) FINISH & CHASE - bronze feeder gates & sprues are cut off and various pneumatic tools.

grind, sand, & polish until the bronze sculpture looks exactly like the original wax sculpture.

9) WELD - numerous sections are welded together and polished smooth.

10) PATINA - various chemicals are applied to the surface both cold & hot to age the metal into various colors. Paste wax is applied to hold the patina color and add a protective polish or shine.

11) BASE - some works are attached to wood or marble bases unless they were designed with bronze bases.

FOR EDITION COPIES:

1) RUBBER MOLD - a flexible rubber is coated over the original piece and a rigid plaster mother mold holds it in place. This is a time-consuming & difficult process which can be costly.

Note: the original sculpture can be made of any material: wax, metal, stone, wood, clay, etc.

2) WAX COPY - hot wax is poured into the rubber mold and allowed to cool solid.

3) CLEAN WAX - the wax is removed from the mold and carefully cleaned to remove all seam lines, air bubbles or flaws.

4) REPEAT PROCESS ABOVE - repeat each step above for each edition copy.

I began working as a Patina Specialist at ARTWORKS Foundry & Gallery in 1985-88. Even after securing a full-time teaching position at Merced College in 1988, I return to the foundry in Berkeley, CA to cast new works, create edition copies, work on large-scale sculptures and pursue 3D printing enlargement projects. For several decades I kept an art studio right next door, splitting my time between working on new sculptures there and creating waxes from my home studio.

Shown below: soft rubber mold surrounded by rigid plaster mother mold used to pour hot wax duplicates of 7 edition copies.

Teaching the Bronze Casting Process at Merced College

Seen here pouring molten bronze metal into plaster molds.

For 35 years I taught bronze casting in my SCULPTURE: 3D Foundations class at Merced College, where I would produce a variety of sculptures each semester for demonstration and lecture purposes with my students. I retired in 2017.

ARTWORKS FOUNDRY

Click the button to see various sculpting processes offered at ARTWORKS Foundry.

Various Sculpting Methods

- The Lost Wax Bronze Casting Process -This process is very time consuming, laborious and costly.Small works take approximately 4 to 6 months to create and life size works can take up to a full year when the Foundry is busy.

Teaching the Bronze Casting Process at Merced College

ARTWORKS FOUNDRY

Click the button to see various sculpting processes offered at ARTWORKS Foundry.

- The Lost Wax Bronze Casting Process -
This process is very time consuming, laborious and costly.
Small works take approximately 4 to 6 months to create and life size works can take up to a full year when the Foundry is busy.