Techniques and Tips

Technique: Andrew DeVries: Sculpture From Start to Finish

Technique: Andrew DeVries: Sculpture From Start to Finish

Massachusetts-based artist Andrew DeVries controls every aspect of his career, from casting his own bronzes to running his own art gallery.

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by John A. Parks

2005, bronze,
19 x 18 x 7.
All artwork this article private collection.

It’s all there already,” says Andrew DeVries in describing how one of his sculptures begins. “I make a line drawing, usually without a model, but the whole thing is already completed in my head.” A passionate sculptor of the figure, DeVries draws on his many years of studying dancers to fire his imagination for sculptures that explore the drama and poetry of pose, posture, and gesture. In Heavenly, for instance, a dancer stretches out en pointe, caught in an ecstatic gliding moment. This, like many of the artist’s smaller sculptures, was done from memory, a process that he finds enhances the clarity and sense of the piece. He recalls Degas’ famous remark that, “It is very well to copy what one sees; it’s much better to draw what one has retained in one’s memory.”

Not only is the artist’s vision comprehensive from the outset but he also manages to retain control of all the technical aspects of realizing a sculpture all the way to completion, eventually exhibiting and marketing the work through his own gallery. The process of making a bronze is long, complex, and labor-intensive and comprises seven stages: sculpting the original in wax or plasticine, making a rubber mold, making a hollow wax positive, making a ceramic shell mold, casting the bronze, chasing the bronze, and putting on the patina.

Sculpting the Original

After making his preparatory line drawing, DeVries begins each sculpture by building an armature, or a metal frame placed on a wooden base. Since he knows that various parts of the sculpture will have to be cast separately, he equips his armature with joints attached with long screws so that he will be able to dismantle them from the outside. If the sculpture is to be a small table-size piece, the artist will begin working with wax right over the frame. If the work is larger, he will build further mesh structures over the frame and work on top in plasticine. DeVries models his small sculptures in microcrystalline wax, which is a somewhat hard substance at room temperature but quickly becomes pliable when heated. The artist uses a small propane torch to heat small pieces as he builds up his figure. Wax allows for endless changes in both addition and subtraction, and DeVries has a large variety of tools for shaping and modeling. “You have to heat the tools with a torch so that they cut into the wax in just the right way,” he says. “Part of the skill in sculpting comes from understanding just how hot a tool needs to be to give you the right feel or resist as it moves the wax.” For his larger figures, the artist uses an industrial plasticine, a mixture of clay and oil, that also needs to be heated slightly to become workable. DeVries will work on his sculpture anywhere from a few days to a few weeks, depending on its size and complexity.

2004, bronze, 35 x 27 x 12.

Once the model is complete, many sculptors consider their task finished and send the piece off to a foundry to be cast in bronze. Not DeVries. “By doing my own casting, I get to control every part of the production,” he says. “If somebody else is finishing the surfaces they might not always understand the form in the same way I do, and they might not give the same care and attention.” In order to undertake the casting process DeVries has acquired a 4,000-square-foot studio space complete with an office area from which he runs the business side of his enterprise. A separate building houses the foundry, the ceramic mold room, and a space for photographing finished pieces. The artist employs an assistant for only one day a week and does everything else himself.

The Rubber Mold

The process of casting in bronze begins with dismantling the original into parts for mold-making. Often this means removing arms or legs as well as a section of the head, and perhaps the middle of the torso. “You have to consider how the bronze is eventually going to pour,” says the artist. “You can’t make it pour uphill, so you often have to make the extremities separately.” Once the original has been broken down, the artist makes a rubber mold of each of the parts. For big areas, such as the torso, the mold may be made in several pieces, and the artist places shims (thin sheets of metal) into the wax or plasticine to separate the mold later. “There are many different kinds of rubber-mold material,” says DeVries, “including silicon, latex, polyurethane, and polysulphides. Each has a slightly different feel and flexibility.”

The rubber-mold material is painted carefully onto the surface of the model in successive layers until it has reached a sufficient thickness. Once the rubber has cured, a thick layer of plaster is applied on top of it, separated by an application of Vaseline so that it will not stick. If the sculpture is large, the plaster is reinforced with hemp or burlap, and in the case of a very large sculpture, steel reinforcement may be used. This plaster layer, known as the “mother mold” or “backup mold,” provides a strong, inflexible support for the rubber mold. Once it has set, the plaster is then separated along the shim lines and removed. The rubber mold is then also separated along the shim lines and removed from the original.

The Other Side of Eden
1991, bronze, 62 x 48 x 20.

Wax Casting

The artist now uses the rubber mold to create a wax positive, a version of the original that is hollow. “This allows me to make a mold of both the inside and outside of the hollow wax shell, which will eventually be made in bronze,” says the artist. “Bronzes have to be hollow for several reasons, but the main reason is that bronze shrinks and distorts as it cools. If you were to cast the figures solid, they would deform badly by the time the bronze was cool.” The hollow wax casting is made by pouring molten wax into the rubber mold, waiting a short amount of time, and then pouring it out again. A thin layer of wax, cooled by the surface of the mold, remains inside. Because the rest of the wax has been poured away, a hollow version of the original model remains. The wax model must now be chased, or finished. “Often there will be tiny problems where the wax hasn’t poured fully into a detail or there is a seam apparent from the mold,” says the artist. Using a blowtorch and a variety of metal tools he can now work out these imperfections with great delicacy.

At this stage DeVries must consider how the bronze is going to pour into the mold. He attaches long, solid bars of wax, known as gates, to the exterior of the wax model. These form hollow tubes in the next stage, which will act as air vents to allow the metal to move freely through the mold. The large rectangular block that DeVries adds at the top of the gates will form a “pour cup” for the bronze. Another consideration at this stage is how the next mold, the ceramic shell mold, will be handled when it’s hot. Often a further handle will be added, especially if the sculpture is large. By this time the wax model appears to have acquired a number of strange additions, but all are necessary before proceeding to the next stage.

The Ceramic Shell Mold

The ceramic shell mold is a mold of both the outside and the inside of the wax positive, made from a material that will be able to withstand the heat of molten bronze. First, the entire wax positive is covered with a thin coat of slurry, a fine ceramic material, by dipping the whole piece or by pouring the slurry over it. After this has set hard it is covered with successive layers of a heat-resistant stucco made from silica. Each successive shell becomes thicker and harder as the material changes from a fine grain to a coarse grain.

The Bather
2005, bronze, 26 x 54 x 26.

Because about 12 hours of drying time is required between each layer of stucco, it generally takes several days to complete this process. The completed mold is then placed in a dewaxing oven and heated very quickly to about 2,000 degrees Fahrenheit before being reduced to 400 degrees Fahrenheit. The initial flash heating to a high temperature ensures that the wax melts quickly enough that its expansion doesn’t crack the mold. The liquid wax now pours out leaving a perfect mold of the original inside. This is the essence of the traditional lost-wax process. The lost wax will soon be replaced with molten bronze.

Casting the Bronze

DeVries next moves to the casting pit, which is built in a shed on the side of his studio. This is the most exciting but also the most dangerous part of the process, so DeVries wears a Zetex fire-resistant coat, fireproof boots, and a large face mask with a transparent viewing window. These days he also wears a thick wool hat because his hair has been singed to a crisp several times in this process. A furnace fired with propane and forced air is used to heat a silicon-carbide crucible to a temperature of about 2,200 degrees Fahrenheit. Ingots of bronze are slowly added to the crucible, with care being taken to first heat them on top of the furnace to drive off any moisture held in the metal. As the bronze heats and eventually melts, slag (impurities) is removed from the surface with a skimming tool. Meanwhile, the mold itself is heated in a preheat oven—essentially a large metal box also heated with propane jets. The mold must become almost as hot as the bronze for the metal to flow freely.

Once both mold and bronze have been sufficiently heated, the mold is removed from the preheat oven by hand, using a pair of Zetex gloves. “I’ve got about 30 seconds to get the mold out of the oven and into the sand pit before I start feeling too much heat,” says DeVries. The hot mold is packed into the sand at the right position to receive the bronze, and the artist then opens the furnace and attaches a large set of pull-out tongs (a caliperlike device) to the crucible. These are locked in place and attached to an electric hoist set on an I-beam above. The crucible is then lifted up and pulled along the I-beam on runners to a position over the mold.

1998, bronze, 39 x 21 x 12.

Using the attached tongs, DeVries tilts the crucible toward the mold, pouring the bronze into the pour cup. This is the most dramatic moment of the whole process, as the white hot metal streams from the glowing crucible and the whole area pulses with heat. “It’s important to get a smooth and steady flow,” says the artist. “Any interruption could result in what’s called a chill line or a cold shut: places where the metal doesn’t flow together and you get small gaps or deformation.” The process is all over in a minute or two, and the mold must then be left to cool for a considerable period of time. Once cool, the ceramic mold is broken away from the bronze using a hammer and chisel. To make any further copies of the piece the artist must return to the rubber mold and take the process from there. The completed bronze is then cleaned by sandblasting and is now ready for reassembly and chasing.


The various pieces of the sculpture must now be reassembled by welding. Once this is completed, the surface must be finished, removing all the welding seams and repairing any imperfections that have occurred during the casting. This process is known as chasing. A variety of power tools is used to grind down the welded seams, and the final finishing is done by hand. Hammers and chisels replace texture in areas that have been obliterated by seams, a variety of small files are used to finish details of the form, and the piece is then sanded with abrasives to the desired finish. As with the other stages of the bronzing process, DeVries enjoys the artistic control that comes from taking charge of these creative details.


The final step in the whole sculpture process is called patination, or the addition of a patina. Eventually all metals will acquire a patina if exposed to the air because of the action of trace chemicals and the gradual process of oxidation. Sculptors use a variety of chemicals to achieve different looks and colors of patina. Most of them are applied by heating the sculpture anywhere from 200 degrees to 300 degrees with a blowtorch and applying the chemicals with a brush or an airbrush. “It’s very much a performance at this stage,” says DeVries. “No two patinas ever come out quite the same, and you have to be aware of nuances that occur as you apply the chemicals.” Some patinas bring about radical color changes, while others impart extremely subtle and rich color to the bronze.

Tres Jolie
2001, bronze, 32 x 14 x 8.

Once the patina has been achieved, the bronze is washed to remove any toxic chemicals and then covered in a coat of wax and polished. It remains only to mount the sculpture on a plinth. “These days I prefer stone,” says DeVries, “and I have a local supplier who cuts granite blocks for me.” The artist notes that collectors often place large bronzes outdoors, where their appearance is further affected by exposure to weather. “People should really wax a bronze sculpture once a year to avoid uneven weathering,” he says. “If they live near the ocean it should be more often.” DeVries says that freezing does not really affect bronze, except in cases where the sculpture has been exposed to a lot of water.

The Business of Sculpture

Several years ago DeVries opened his own gallery in rented space in Lenox, Massachusetts, a town know for its galleries and a summer influx of art connoisseurs. In an attempt to increase sales, DeVries has applied the same care and energy he brings to his work to the marketing end of his business. The artist keeps careful records of clients, prospective clients, and visitors and does four big mailings a year. He revolves the work in the gallery and mounts opening parties several times during the summer season, sometimes printing a color catalogue. “I also spend as much on advertising as I can,” he says. In order to ease entry-level collectors into making a purchase, the artist also produces one noneditioned piece, a small and handsome bronze bell, which sells for less than $500. The sculptures themselves are generally made in editions of 12. If a piece is sold to someone within striking distance, the artist will also assist with installation, guiding his work all the way to its final home.

About the Artist

Andrew DeVries was born and raised on a farm near Rochester, New York. He left school at the age of 15 and remained on the farm for the next five years, painting in his spare time. At the age of 20 the artist moved West, eventually living in Denver, where he spent two years drawing and painting the dancers of the Denver Ballet. One day Reike Maria Love, the artistic director of the ballet, suggested that he try sculpture, and as soon as he felt the clay in his hands he knew that he had found his calling. He was apprenticed to sculptor Ed Dwight and learned about metalwork in the foundry of artist Lee Schenkeir. He also credits Raelee Frazier for teaching him about the art of mold making. DeVries won the Walter and Michael Lantz prize from the National Sculpture Society (NSS) in 1991. In 1994 the NSS selected his piece The Chariot for their first international exhibition in Seravezza, Italy, and in 1996 awarded him the Lindsay Morris Memorial Prize. DeVries’ sculpture is in private and corporate collections around the United States as well as in Australia, Canada, England, Germany, Ireland, Israel, Korea, and Portugal, and is also in the U.S Library of Congress. To view more of the artist’s work, visit his website at

John A. Parks is an artist who is represented by Allan Stone Gallery, in New York City. He is also a teacher at the School of Visual Arts, in New York City, and is a frequent contributor to American Artist, Drawing, Watercolor, and Workshop magazines.

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Watch the video: Making bronze octopus sculpture (July 2021).