Studio

What is the Lost Wax Process?

Often the question is asked: "how do you cast bronze?" to which my usual reply is: "A very simple 35 step, 12 week process." And thats on a good day. The lost wax process is an ancient one dating back over thousands of years. Different metals were melted together as "alloys" to improve strength, durability, pourability, forging capacity and a number of other properties. Today we have hundreds of varieties of metal alloys within the bronze family, the steel family and the aluminum family. Just as gold has karat quality that increases the monetary value or strength in purpose, so too do these other metals. My studio employs many different metal alloys to succesfully achieve the results you see in my portfolio. I don't design average Art so naturally the average practice doesn't always work. Primarily we cast Silicon Bronze, a high copper alloy ideal for small, detailed works and for public projects. Naval Bronze, a lower copper alloy used to cast large, light weight prototypes also provides significant economic savings that can be passed on to my customers. Hurculoy Bronze has a high zinc content and is poured into thiner pieces that require improved tensile strength. Stainless steel is the hardest and most durable alloy in the steel family. At double the casting cost, it is difficult to finish but once done lasts forever. Aluminum alloys vary in their castability, weldability, resistance to corrosion and strength. It can provide some economic savings and is very lightweight. (which is why I love it) Each of these metals has its own value, each provides a benefit and a compromise. I use them all for better or worse when trying to realize a great design. My work challenges the capabilities of how any metal can perform (just ask my foundries and engineers). I believe that is part of my job as an artist. For any questions regarding the specific make up of your sculpture or one you are planning to purchase, contact us and we will be happy to provide a certificate of authenticity with all the details. The following breakdown begins to explain the long process that all these metals go through once selected for employment in the making of my Art. First, the artist creates the sculpture, usually in clay or wax, although the original may be made from other materials as well. I sculpt in paper and wax. Paper for the original design and form, wax to hold the paper image in place for casting directly or for moldmaking. This can take as long as an artist takes. As Michaelangelo once said to the Pope regarding the comletion of the Sistine Chapel "It'll be finished, when it's finished!!" The Rubber Mold A flexible rubber mold is made on the artist's original. This modern material is able to capture every detail and remain flexable. A plaster support case holds this rubber mold in place. The Wax Casting Molten wax is then poured into the rubber mold, producing a faithful casting of the sculpture. Wax Chasing The rubber is pulled back to reveal the copy within. When the wax casting is removed from the mold, an artisan hand finishes it to perfectly match the original. Gating Wax rods called gates are applied to the wax casting to allow the wax to be removed and funnels called sprues are attached to receive the molten bronze. Investing The wax casting is coated with several layers of a liquid refractory ceramic, creating a stable mold, which is allowed to cure for several days. Burn Out The ceramic mold is fired in a kiln, which bakes the ceramic and burns out the wax, leaving a cavity in its place. (Thus the term, Lost Wax) Organic materials such as paper can be used in the lost wax process as well. So long as they will burn out along with the wax. Casting The ceramic mold is then filled with molten bronze at a temperature of 2000 degrees Fahrenheit. (Bronze is a varying alloy of copper, zinc, silicon and other trace metals). Breakout After the bronze has cooled, the ceramic mold is carefully broken away, revealing the sculpture within. Sand Blasting Fine sand particles are blasted under air pressure to remove the last traces of the ceramic that adhere to the bronze. Chasing The raw casting is then turned over to another artisan who cuts away the gates and sprues, welds the pieces together, then grinds and blends these areas into the casting reproducing the original textures. Patination The chased metal is now cleaned. Chemicals are applied and heated to give it the chosen color according to the artist's specifications. Wax or laquer is applied to fix the color and prevent any further oxidization. Once cool, the sculpture is then polished revealing the rich colors and textures of the bronze. For outdoor work I use high quality auto finish or powder coating for durability.