Terminology

Bronze

An alloy traditionally composed of copper and tin. Bronze is of particular historical interest and still finds wide applications. It is more complex than copper and pure iron, fusible, corrosion-resistant and easier to cast.

Bronze Sculpture

Bronze sculptures are created through an indirect process. Wyland designs the original artwork in wax or clay, and then a fine art foundry reproduces it using a multi-step procedure called "lost wax" investment casting. Each sculpture is constructed individually by hand, including molding, pattern making, investment, pouring, tool, assembly, and patination. Just one bronze casting can command the attention of up to a dozen skilled artisans and can take several weeks for the art foundry to complete. Successful sculptors are generally considered experts in their subject's form, detail and behavior. This expertise is evident in their work, as the art is recreated in a way that is accurately portrayed and artistically appealing.

Casting

In creating a bronze sculpture, a wax reproduction of the original clay sculpture is covered in a rock-hard ceramic casting shell or "investment." When the wax has been melted out, the shell will serve as a mold for the molten bronze and, once hardened, is carefully broken away and cleaned from the casting. Channels through which the bronze is poured, called "sprues," are cut off, and all parts are sandblasted to prepare for reassembly.

Chasing

Chasing is a method of finishing bronze casts by removing minor imperfections and smoothing rough spots. Often, the metal surfaces are embossed, hollowed, or engraved with steel tools to recreate the artist\'s subtle surface texture.

Dewaxing/Burnout

The process of dewaxing a cast of a sculpture best defines the term "lost wax" casting. The dewaxing occurs when the dried ceramic shell, still containing the wax pattern, is placed with its opening down into a hot kiln. As the temperature rises, the wax melts and flows out of the shell, leaving a cavity in the form of the artwork.

Fine Art

Describes the categories of artworks that are traditionally considered aesthetically significant. They include architecture, painting, sculpture and many graphic arts and are contrasted with decorative and applied art, in which function is as important as aesthetic considerations.

Gating/Spruing

The finished wax version of a sculpture is prepared for ceramic investment by attaching a plumbing system of wax called "gates" or "sprues." The gates and sprues form the channels through which the melted bronze will travel to the artwork. Later in the casting process, the space occupied by the gates and sprues becomes runways through which the metal flows and trapped gas escapes.

Humidity

Humidity is the percentage of water content in the air and is an essential contribution to patina development. All bronze is microscopically porous. Therefore, it takes on a certain amount of air. This air will contain ambient humidity or water. A humidity swing is a rise and falls in humidity in 24 hours.

Investment

Investment is building a ceramic shell around a wax replica of an original clay sculpture by dipping the sculpture into a pancake batter-like mixture of slurry and sand. Between coats, the shells are suspended in drying racks in environmentally controlled rooms. The process is repeated up to a dozen times, beginning with fine slurry and fine sand to capture surface detail and graduating to coarser coats for strength. 

Lost Wax Process

(Cire Perdue) A casting process using a wax model encased in a molding material, such as sand or plaster, then melted away, leaving a hollow mold into which the molten metal is poured.

Medium

A medium is any particular material used by an artist: oil paint, clay, ink, pastel, wood, concrete, or bronze. 

Mixed Media Sculpture

A blend of precious metals is combined with hot-torched acid patinas. Originals arrive at the foundry in plasticine, which results from sculpting and resculpting soft clay. From these originals, first-generation models are created. Each sculpture is sectioned into many parts and placed into molds to create individual cavities. Once these metals have solidified in the molds and are released, the pieces are welded together to form the final shape of the sculpture. Meticulous handwork with fine stainless steel tools recovers detail lost in the welding process. At that point, each original sculpture is bathed in hand-applied precious metals and various patinas. In finishing, the sculpture is hand-relieved with a combination of steel wool and sand to release the color and texture of the original metal form. 

Mold Making

A mold allows wax replicas to be made of an original clay sculpture and makes the casting of limited editions possible. To construct the mold, a molding compound is painted or troweled onto the original and built up until it is a thickness that is durable yet retains flexibility. Molds are usually made of flexible rubber or silicone and can be used for the entire limited edition. A rigid support of plaster or fiberglass called the mother mold is built over the finished rubber mold. The outer mold helps the rubber retain its shape and position and allows the mold to be handled. 

Patina

A patina is a chemical coating that adds a colorful finish to a metal sculpture, a particularly effective treatment for bronze. Patinas give various attractive green, brown, blue, and black. Natural patinas, like the creative element of fine art, are uncertain. That is probably why artists and collectors for 500 years have cherished works of art with rich and deep patinas that developed over time. Art consultants may not be able to predict with exactness the rate at which natural patinas create. Still, they can know the factors contributing to change: atmosphere, temperature and humidity.

Signatures

Most artists today sign their prints in pencil. The signatures have come to stand for, among other things, a stamp of quality and the print's authenticity. It would therefore be improper for an artist to sign a reproduction if it is marked as such or to sign inferior prints that do not meet the artist's standards. 

Temperature

An essential factor in the aging of natural patinas is temperature or the temperature swing. For example, the temperature cycle of Tucson, Arizona, may vary from 40-50 degrees in 24 hours, while other parts of the country may be stable from season to season. These fluctuations Ð or lack thereof -- can affect the appearance of a patina.

Wax Patterns

Wax replicas (called wax patterns) of an original clay sculpture are made by filling a mold with liquefied hot wax and then rotating the mold until all cavities are filled. Next, the wax is poured out, leaving a thin skin on the interior of the mold, one-eighth inch to three-sixteenth inches thick. A hollow wax replica of the original artwork is revealed when the mold is pulled away. The hollow wax patterns are tooled to correct all wax pouring imperfections, refined details, and smooth surfaces. The artist will sometimes oversee the work of the artisans in this stage. 

Welding/Finishing

Larger sculptures are often cast in several sections and then reassembled by welding the pieces together. The welds are ground down and textured to match the surrounding surfaces making the seams unnoticeable. Artisans and metal workers use various hand and power tools in the finishing stage to achieve or refine final characters and accentuate textures.