Bronze casting process difficult
November 12, 2004
Clyde Davis: Local Colunist
When it comes to the bronze-casting process, by which art is reproduced and sculptures made into limited editions, most of us are hopelessly lost or misinformed.
No kidding, I used to think they actually carved the bronze with some kind of tools, the way a carving reproducer works on wood (it’s kind of like a giant lathe). Since we focused last week on an artist whose primary product is bronze reproduction, I thought it might be interesting to bring in the reproduction process itself this week.
It wasn’t until a couple of years ago that I was relieved of my illusion regarding how bronzes come into being. That may be hard to believe, but it stems from the fact that I am not the most technically oriented guy in the world, so this sort of puzzle was one I never would have figured out.
At this time I took a piece of sculpture, a walnut carving entitled “Mescalero Madonna,” to John Muir for casting in bronze.
Any object may be cast in bronze, so a wood carving works fine.
This was when I became enlightened about how bronzes are born.
A heavy rubber mold is made around the object. Since many sculptors work in clay, the mold-making probably has to be done very carefully in those cases, to avoid damage to the original. If the original is of any size, it will need to be supported by an armature, which is kind of like a skeleton.
So prior to casting, the artist has built a skeleton and created her piece in clay over the skeleton, usually composed of wire.
Then the bronzecaster makes her rubber mold from the finished piece. With a very large sculpture, say a life-sized person, the process will be done in pieces. I remember once, Muir was casting a life-size Roy Rogers, and Rogers was actually molded in quite a few pieces.
After he has created the rubber mold, wax is poured into this and usually the artist will check the piece at that point to make sure it is still what he wants. Then a heavy ceramic mold is constructed from this wax model, ceramic being the material that can handle the heat of molten bronze. Obviously, a clay original is far more fragile than a woodcarving, and my understanding was that you may only get one chance at your clay piece.
Then the molten bronze is poured into this ceramic mold, which I forgot to mention is made in two or more pieces. After cooling, the original still has to be cleaned, sanded smooth, and then finished. For a lot of artists, this is the point where they re-enter the process; by taking charge of the cleaning yourself, you have a chance to do some final shaping with your Dremel. I remember a casting of a cat that I had, which I made for my wife, on which I did considerable reshaping.
The patina also gives you that chance to re-enter the creative process. For example, the above-mentioned cat was patinaed in black. A Mescalero Madonna that I cast for my mom was patinaed to look like gray marble.
I hope that this will enlighten you as to the amount of work and time that it takes to make a good bronze reproduction, and deepen your appreciation for this.
Clyde Davis is pastor of First Presbyterian Church in Portales and an instructor at Eastern New Mexico University. He can be contacted at: