My Process
After inspiration has struck, and after I have the sketches ready then I start to explore the medium.
The Casting Process
The process of creating a bronze sculpture is a long and interesting one and requires the assistance of a foundry. The first thing that happens is once the artist has been inspired and has come up with a very viable idea is to build an armature. This is made of wire and will support the sculpture structure.
Once the armature has been made, the clay has to be applied in a way where it’s solid and where it expresses the idea of the artist. Depending on the size, and complexity of the sculpture this can take up to three or four weeks before the sculpture is actually realized. The good thing about creating an armature and working in clay is that one doesn’t have to worry about cracking or breakage because the clay is not going to be fired. It’s just used for modeling and for creating the sculpture.
Creating Bronze Sculpture
The next thing that happens after the clay sculpture has been completed to satisfaction is that the foundry will either come to the artist’s studio or the artist will deliver the clay sculpture to the foundry and a mold technician will make an actual mold, a cast, which will cover the clay sculpture.
The first material that is applied to the clay sculpture is silicone, which takes a couple of days to dry. The next material that is applied is gesso. The gesso will encase the sculpture in such a way as to protect it and to adequately mold to its shape. Generally speaking, when we’re talking about horse sculptures, the foundry can make the mold in two pieces; the left side and the right side because it has to be divided in half.
Wax Model
They will usually make the tail part or anything that protrudes other than the legs as a separate mold. Once this mold has been made, a red wax sculpture is created by removing the clay sculpture, putting it to waste, putting back the pieces of the mold, sealing the mold, and then pouring in a very thin layer of red wax.
This red wax is going to show exactly what the sculpture is going to look like and to serve as the model for the bronze sculpture. What happens next is after the artist has inspected the wax model and made any corrections, then the real work begins. The wax sculpture is then put into an encasement made out of terracotta and gesso, which can withstand the temperature of the oven and can also withstand bronze being poured into it.
At this point, the artist can make any corrections to the wax model.
Preparing for Bronze Fusion
Then, canals are attached to the wax sculpture, which will feed into the wax sculpture space because this is considered the lost wax process.
Once this encasement has been made, the wax will remain inside until it’s baked in the oven and then will melt, leaving a gap where the bronze will then be able to be poured in and fill the space. This whole process in terms of the wax sculpture takes about eight days in a low oven, and the wax evaporates. In fact the wax melts very slowly and carefully. Once they take it out of the oven you have a mold with the exact imprint of the sculpture on the inside. At that point, the sculpture can be cast in bronze.
Polished Bronzes
The wax no longer exists, but the gap inside of this encasement is now open and can be infused with the liquid bronze. Once that has happened, which also is done gradually and takes a while, the total measurement of the actual bronze coating is about eight millimeters. It has been carefully set up so that when the bronze is poured in, it will only be the thinnest outer layer of the sculpture. The sculpture will be hollow on the inside. It cannot be solid, because it would just be too heavy since bronze is a dense metal.
Patinate Bronze Sculpture
Once that has happened and the bronzes are removed from the mold, they’re cleaned up and polished and at that point, the patina will be applied. The patina is made out of oxides. Oxides are naturally occurring chemicals that will then be applied with a torch to fuse to the raw bronze to the artist’s satisfaction. (Hence the reason bronze oxidizes when exposed to the elements). And that is the art of bronze casting. You can see more examples in my sculpture gallery or at my upcoming exhibitions.
