The Creative Process of Casting in Bronze.
The following is a summary of the multiple stages in bronze making. A video of this propcess is in development and will be available.
Model making. There are several steps involved in creating replicas of the sculptor's original design and clay model:
Mold making. A reproduction mold is made from the application of latex, polyurethane or silicone and plaster onto the artist's model.
Waxing. Once this cast is completed, molten wax is poured in, until there is an even coating of a proper depth covering the inner surface of the rubber form.
Wax removal and chasing. The wax duplicate is gently removed from the mold pattern, scrutinized for flaws which are then carefully removed or "chased" by the craftsman.
Spruing. The wax copy is then "sprued or gated". That is, a treelike structure of wax is crafted from a ceramic cup at the top. These wax pathways, "sprues or gates", are for the eventual molten casting mixture to flow into the die from above and for air to release.
Slurry and grit: the creation of the ceramic shell. The sprued wax copy is dipped into a slurry of silica and then into a vat of dry crystalline silica. This process is repeated until an ideal thickness and solidity is achieved as a ceramic shell begins to emerge.
Burnout. The ceramic shell coated piece is placed in a kiln where the wax is melted away in the classic "lost wax" method. Now all that remains of the original artwork is the negative space, previously occupied by the wax, inside the remaining hardened ceramic casing. The attached feeder and vent pipes and upper cup are also now hollow.
Pouring. The hard ceramic shell is ready to receive the molten bronze. After the pour, the filled casing is allowed to cool.
Release. The shell is hammered and sandblasted away leaving a rough casting of unfinished bronze. The supportive sprues and gates, which are also faithfully recreated in bronze, having served their purpose, are now cut away.
Metal-chasing. Now the artisans weld, chase and polish the bronze to remove any signs of the intermediate casting process and restore the texture and integrity to the likeness of the original model.
Patina. The surface of the metal is heated so that various chemical solutions can brushed onto the bronze casting which creates the desired color or shading on the metal. The patina is then sealed with a finishing wax. The fine art bronze sculpture is now complete.
A final word. The professional sculpting team, although they are immersed in labor intensive and hazardous work, do not lose sight that they are involved in a creative process that will yield a sacred work of art. It is a continual source of joy that their sculpture will bring a community to a common focal point of timeless spiritual beauty becoming a lasting legacy of a shared spirituality.
Though the toil of our hands is now complete, our spiritual task continues as we pray that the Spirit may use these art forms of beauty as healing instruments of His grace.
The following is a summary of the multiple stages in bronze making. A video of this propcess is in development and will be available.
Model making. There are several steps involved in creating replicas of the sculptor's original design and clay model:
Mold making. A reproduction mold is made from the application of latex, polyurethane or silicone and plaster onto the artist's model.
Waxing. Once this cast is completed, molten wax is poured in, until there is an even coating of a proper depth covering the inner surface of the rubber form.
Wax removal and chasing. The wax duplicate is gently removed from the mold pattern, scrutinized for flaws which are then carefully removed or "chased" by the craftsman.
Spruing. The wax copy is then "sprued or gated". That is, a treelike structure of wax is crafted from a ceramic cup at the top. These wax pathways, "sprues or gates", are for the eventual molten casting mixture to flow into the die from above and for air to release.
Slurry and grit: the creation of the ceramic shell. The sprued wax copy is dipped into a slurry of silica and then into a vat of dry crystalline silica. This process is repeated until an ideal thickness and solidity is achieved as a ceramic shell begins to emerge.
Burnout. The ceramic shell coated piece is placed in a kiln where the wax is melted away in the classic "lost wax" method. Now all that remains of the original artwork is the negative space, previously occupied by the wax, inside the remaining hardened ceramic casing. The attached feeder and vent pipes and upper cup are also now hollow.
Pouring. The hard ceramic shell is ready to receive the molten bronze. After the pour, the filled casing is allowed to cool.
Release. The shell is hammered and sandblasted away leaving a rough casting of unfinished bronze. The supportive sprues and gates, which are also faithfully recreated in bronze, having served their purpose, are now cut away.
Metal-chasing. Now the artisans weld, chase and polish the bronze to remove any signs of the intermediate casting process and restore the texture and integrity to the likeness of the original model.
Patina. The surface of the metal is heated so that various chemical solutions can brushed onto the bronze casting which creates the desired color or shading on the metal. The patina is then sealed with a finishing wax. The fine art bronze sculpture is now complete.
A final word. The professional sculpting team, although they are immersed in labor intensive and hazardous work, do not lose sight that they are involved in a creative process that will yield a sacred work of art. It is a continual source of joy that their sculpture will bring a community to a common focal point of timeless spiritual beauty becoming a lasting legacy of a shared spirituality.
Though the toil of our hands is now complete, our spiritual task continues as we pray that the Spirit may use these art forms of beauty as healing instruments of His grace.
© 2012 T.A.S.A., all rights reserved.
