© Susan Geissler 2013       Built by andrephoto.com
Susan Geissler

THE FOUNDRY PROCESS

 
A Long Journey from Clay to Bronze
1.) A mould is created, in several steps, by painting a liquid synthetic, rubber-like material directly onto the finished clay model. 2.) After the rubber-like mould has cured, it is coated with a fibreglass or plaster shell to hold its shape. 3.) When this “mother mould” is completed, it is pulled off of the clay and Cleaned, leaving a ‘negative’ image of the original model.  (The clay is always somewhat damaged in this process. 4.) Molten wax is then applied to the mother mould-either by painting it onto the inside of the mould, or by pouring wax into the mould and draining it, or both-taking care to be sure that every nook and cranny is filled with wax. This process may be repeated numerous times to ensure that the wax is the correct thickness. 5.) When the final layer of wax has cooled and hardened, the wax is removed from the mother mould, leaving a wax positive of the original piece.  After the imperfections and seam lines are ‘chased’ or cleaned up, the hollow wax model should be an exact replica of the original piece. 6.) Wax channels—called gates and sprues—are added to the wax model a “plug” is then generally cut out, so that in the next step, liquid shell material can fill the void inside of the hollow wax. 7.) Now it’s time to make the shell, which will be the mould for the molten bronze.  To accomplish this, the wax positive—or pieces of the wax if it is too large or intricate to case in one piece, which is most often the case,--is dipped into a ‘slurry’ solution and then coated with fine grains of silica material.  This step is repeated three or more times, over a period of many days, gradually increasing the size if the silica grains, until the wax model is evenly covered with this shell, which is then placed into a large “burnout” oven.  The heat hardens to the shell, while melting the wax out; hence, the term—lost-wax process.  The hollow shell is a negative of the original sculpture.
What’s involved in turning a clay model into a finished bronze? Here’s an overview of some of the steps, using the lost-wax process.
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Sculptor
© Susan Geissler 2016      Built by andrephoto.com
Susan Geissler

THE FOUNDRY PROCESS

 
A Long Journey from Clay to Bronze
Back Back
1.) A mould is created, in several steps, by painting a liquid synthetic,rubber-like material directly onto the finished clay model. 2.) After the rubber-like mould has cured, it is coated with a fibreglass or plaster shell to hold its shape. 3.) When this ‘mother mould’ is completed, it is pulled off of the clay and cleaned, leaving a ‘negative’ image of the original model.  (The clay is always somewhat damaged in this process. 4.) Molten wax is then applied to the mother mould--either by painting it onto the inside of the mould, or by pouring wax into the mould and draining it, or both--taking care to be sure that every nook and cranny is filled with wax. This process may be repeated numerous times to ensure that the wax is the correct thickness. 5.) When the final layer of wax has cooled and hardened, the wax is removed from the mother mould, leaving a wax positive of the original piece.  After the imperfections and seam lines are ‘chased’ or cleaned up, the hollow wax model should be an exact replica of the original piece. 6.) Wax channels—called gates and sprues—are added to the wax model a “plug” is then generally cut out, so that in the next step, liquid shell material can fill the void inside of the hollow wax. 7.) Now it’s time to make the shell, which will be the mould for the molten bronze.  To accomplish this, the wax positive—or pieces of the wax if it is too large or intricate to case in one piece, which is most often the case,--is dipped into a ‘slurry’ solution and then coated with fine grains of silica material.  This step is repeated three or more times, over a period of many days, gradually increasing the size if the silica grains, until the wax model is evenly covered with this shell, which is then placed into a large “burnout” oven.  The heat hardens to the shell, while melting the wax out; hence, the term—lost-wax process.  The hollow shell is a negative of the original sculpture.
What’s involved in turning a clay model into a finished bronze? Here’s am overview of some of the steps, using the lost -wax process