David’s Sculpture Processes

So many mediums, so little space to share about them (and store them): I work in woods, clay, wax, bronze, steel, paper, gems, minerals, and stone. My “Woodstock” is not a festival in my back yard. It is a zone where hundreds of twisted juniper and pinion branches stand, waiting for me to utilize, to express the image that first spoke to me upon seeing the branch in nature. You see, when I “hunt” for my wood specimens, I go about it in a sacred manner, with prayer, and ceremony. I look for dead standing trees. When I see a form that “speaks” so to speak, I cut it, and bring it to the studio. I’ll sand it to 1000 grit and cut the bottom so that it stands balanced. Then I’ll embellish it with oils or paints, and then mount it using gems or minerals to accent the “spoken” information that the tree first shared with me.

If I carve in wood or stone, of course it is a subtraction process. Power and hand saws are used to rough out the shape. Then its chisels, mallets, rasps, files, and lots of sandpaper! My favorite carving woods are cedars in the Western Red, Incense, and Port Orford Yellow varieties. My favorite stone is the Yule white marble from Marble, Colorado.

The contemporary bronzes I do are either one of a kind pieces, or limited editions. The original piece which I’ll call the pattern, can be made of clay, wax, wood, or whatever material. A rubber molding material is applied directly to the pattern covering it with an even layer about a half inch to an inch thick. Then a plaster cover or “mother mold” is applied to the exterior of the rubber mold to hold the rubber in place for later. The original pattern is removed from inside the rubber mold. Hot wax is poured back in. If the sculpture will be hollow, the wax is slushed and then poured back out so that your new wax pattern is around an eighth inch thick. Otherwise the piece is solid wax not more than three inches thick. This wax cast is then removed from the rubber mold. Next, the wax sprues, gates, and vents are attached to the wax cast. This is a feed system that will bring the metal to the pattern. The sprued wax cast is then dipped into a silica / ceramic slurry. Fine silica sand is spread all around the wet ceramic slurry so that the sprued wax pattern is completely coated. It is allowed to dry and this step is repeated about eight more times. This builds a ceramic shell around the wax that is about an inch thick and is ready for the burnout kiln. The wax is burned out of the mold at around 1,000 degrees. ( Thus the process is called “lost wax casting.”) The hot empty ceramic shell is brought to a sand pit. The lower half of the shell is set in the sand. Bronze that has been heated in a furnace to around 2,000 degrees, is poured into the hollow ceramic shell from a crucible set in a pouring shank *see drawing. Besides sculpting the original, the pour is, indeed, the most exciting step in the process! Within fifteen minutes the ceramic shell mold can be removed from the bronze cast using hammers and chisels. The sprues, gates, and vents are cut off, and now you have your bronze cast. The final surface is “chased” or retextured by grinding, sanding or polishing, chemical patinas are then applied to color the bronze. A base is created in wood or stone, and the finished casting is then mounted to the base. If the piece is to be a limited edition, more waxes are cast, and the process repeated.

BEHOLD: Bronze art that will last thousands of years beyond the life of your couch !

So, when considering a bronze purchase, remember that it will outlast all of the rest of your furnishings, for many, many generations to come.