Lost Wax Method Title

Duane's Limited Edition Bronze Sculptures are made by hand in the USA.

Bronze is a metal compound containing copper and other elements such as tin. Artists have used bronze for creating timeless sculptures since antiquity. While it is not the cheapest medium to work with, the price of the metal is not the determining cost factor. Every step in the process is done by hand and is very time consuming.

How does he do it?

Before he can cast the sculpture in bronze, Duane must first create the original in clay. Depending on the size and complexity, this step alone can take hundreds of hours. Then, a limited number, typically no more than between 1 up to 399, of bronze sculptures are cast one at a time over a long period of time (usually years) using the "Lost Wax Method."


ArmatureThe initial step is to build an armature, typically out of fiberglass. He then coats the surface with clay. In this picture of "Day's End," you can clearly see the brown clay that Duane has already applied to the bottom half of the surface of the armature.



Original Clay Sculpture
Next he sculpts the intricate detail into the clay. This picture illustrates the way "Win, Place & Show" looked after he completed the original clay sculpture.


Mold MakingThe finished clay sculpture is sealed and then a release agent is applied to make it easier to remove the rubber mold later on. Once the original sculpture has been prepared, the first coat of rubber is applied by hand. This step is crucial to obtaining the proper level of detail. The entire sculpture is covered with an even, thin layer of rubber. Once the initial layer of rubber has set, additional coats are applied with "keys" which are used to identify the proper position of the mold when closed. After the rubber has thoroughly set, a back-up shell or "Mother Mold" is created out of fiberglass to support the rubber for the wax pouring process. Next the back-up shell is removed and the rubber pulled gently back so the original clay sculpture can be removed. It can take more than 100 hours just to make the mold for elaborate pieces. After the rubber has been cleaned, the mold is ready to receive the wax.


Wax PouringA wax casting is then made by carefully pouring wax into the mold at 160 degrees Fahrenheit. After the wax has cooled, the back-up shell and mold are removed.


Wax Chasing and SpruingNext the wax is pulled from the mold and hand chased (re-detailed). Wax rods, called sprus or gates, are then attached to the sculpture along with a large cup at one end to allow the molten bronze to be poured into a ceramic shell which is in effect a "secondary" mold created for each casting.


Slurry DippingDipping the wax in a liquid binder solution, called "slurry", that hardens as it dries, forms the shell. This step has to be done in a temperature and humidity controlled room. Since the slurry must be allowed to dry in between each dipping, this process alone can take a couple of weeks! Next it is baked in a kiln at 1800 degrees Fahrenheit. As a result, the wax is "lost" as it melts out of the shell. After de-waxing, the shell is cooled and inspected.


CastingIt is then re-heated to 1800 degrees Fahrenheit and placed in the pouring pit where molten bronze is poured into the hollow shell at 2100 degrees Fahrenheit and allowed to cool and solidify. After removing most of the shell material inside and out, the unfinished bronze casting is glass beaded, water or sand blasted to remove any remaining shell material from the intricate details of the casting.


If the original was sectioned into multiple pieces, it is carefully fitted and reassembled.


Metal ChasingNext, the sculpture is chased/sanded to remove any sign of welding and to prepare the bronze for patination.


PatinationPatinas actually cause a controlled corrosion to occur that imparts an aesthetically pleasing color and/or texture while also providing protection to the bronze metal surface. After the patina is applied with chemicals to achieve the desired look, the sculpture is sealed with a wax coat to protect the finish. Alternatively, a glossy coat of high-grade polyurethane can be applied instead. Some antique and custom patina finishes can take as long as a week or more to apply!


Finally, the completed bronze sculpture is mounted on a custom granite or marble base. As you can see, a lot of work goes in to creating each bronze sculpture. That is why they are not only extraordinarily fine pieces of art, but timeless treasures that will be appreciated for generations to come.Mounting



© 2006 Duane Scott Bronze Art