By Kristen Miller
COKATO, MN For more than two decades, Rory Wallace of Cokato has been mastering the art of patination, the process of chemically treating bronze sculptures in order to create various desired effects.
Applying a patina is an art in and of itself in that Wallace is able to apply chemicals in varying levels of application to make the sculpture appear a certain way.
“I’m trying to invite the eye to do what the artist wants it to do,” Wallace commented, which is determined during an artist consultation.
In the early 1990s, Wallace spent some time working in a foundry, a factory that produces metal castings. He was also doing his own sculpting at that time.
Under the instruction and influence of his uncle, James McNealey, a University of Wyoming art professor, Wallace became involved in the bronzing process.
It was then that he decided to changes careers from the automotive customer industry he was then apart of, and follow the art scene in Colorado.
He is currently doing contract patination for Casting Creations, a foundry in Howard Lake, because the artists had been looking for more complicated patinas.
In addition to his work with the foundry, Wallace has his own business, Wallace Studios.
The process of patination comes at the end of the lost-wax casting process, a method of creating bronze sculptures beginning with a wax model. See side bar for lost-wax process.
Once the final bronze sculpture has been sandblasted to smooth any imperfections, the patina process can begin. Wallace noted that bronze consists of 95 percent copper, 4 percent silica, and 1 percent manganese.
The process of patina goes back centuries and originally was naturally occurring or was a means to protect medals, such as weaponry and utility vessels.
Today, patinas are more commonly used for decorative purposes.
Wallace compared creating a patina to painting a picture in that there are 1,000 ways to do it.
A patina is the layering of different chemicals to get a desired appearance.
Wallace specializes in the hot patina method, in which the artwork is heated and the chemical is applied to achieve a variety of colors and effects.
Some examples of the chemicals he uses includes silver and zinc nitrates, which produce a silver or gray color; ammonium sulfide, which produces a bluish-gray or black color; and chromium oxide, which is green in color.
When creating multiple patinas, as Wallace recently had with 30 Writer’s Guild Awards statues, none of them are going to turn out exactly the same, he said.
Though one “paints” on a chemical, patinas are not like a painting where one will instantly see the color, since multiple layers are applied, Wallace explained.
After layering the chemicals, the patina is then sealed with lacquer or wax and then buffed.
As a patina artist, Wallace offers patina applications with pre- and post-production consultations; maintenance, restoration, and repair of public or private artwork; fine art sculpture, and public and private sculpture commissions.
For more information, visit his website, www.rorywallacestudios.com; or contact him at (612) 986-6643, or email@example.com.
Steps in the lost-wax process
1) An original sculpture/model is made from any desired materials.
2) The original is encased in a mould, which is usually made from a variety of elastomer rubbers.
3) Multiple reproductions of the original are now made by pouring hot wax into the mould.
4) After cooling the wax reproduction is removed from the mould and covered in silica sand to give a ceramic casing around the wax.
5) The ceramic casing is fired (baked), melting the wax which is now “lost” from the ceramic casing, leaving the casing hollow.
6) Molten bronze is poured into the hardened casing.
7) After the bronze cools, the ceramic casing is broken off and one is left with a raw bronze sculpture, which is prepped for finishing by welding, grinding, sanding and sand-blasting.
8) The bronze sculpture is ready for the patina process.