A regular lost-wax casting workshop, in which we cast solid objects, involves three completely different processes. First, we work with beeswax to create the objects and with clay to create the moulds and crucibles. Second, there is the casting process that usually takes place on the second day, and finally there is the finishing of the cast objects. All three stages require different tools and work environments making any workshop an interesting exercise in organization. Here are a few photos to give you an idea of what is involved.
Step 1. Beeswax and Clay
When modeling objects, the beeswax can either be worked cold, in which case it is carved, or warm in which case it needs to be heated somewhat above room temperature. Here the wax objects have been created by carving and then the sprues (the round pieces) have been attached using heat from an alcohol lamp.
Once the pieces are made and the sprues have been attached, moulds are made by forming a clay mixture around the wax objects.
Finally the moulds are incased in a protective layer of clay and the crucible is made and filled with metal.
As you can imagine these two steps are best done in a clay and wax friendly space, and inside, where it’s warm…
…and not, as we did here, in a cold, wet, leaky barn where some of our water bowls were used to catch the rain that was dripping in!
Step 2. Casting
The furnaces can be above ground, below ground, small, large, wood fired, charcoal fired or gas fired. Pretty much any situation can be adapted in order to accommodate a furnace. Although I haven’t tried it yet, I’m sure with good ventilation, the casting could even be done in a room.
Typically, casting Luted Crucibles is done outside with a below ground level charcoal fired furnace whose dimensions are about 12″ in diameter and 12″ deep. This one has a lid to help hold the heat in and the central hole is plugged with a clay cup (the Luted Crucible is inside the furnace under the lid).
Casting can also be done in a purpose made above ground furnace when it is not possible to dig into the surface such as when we did this wood-fired casting workshop in the parking lot of New Mexico School for the Arts…..
….or this charcoal-fired casting demonstration in front of the Museum of International Folk Art.
We’ve also done gas-fired casting workshops in a pedestrian area in central London. Here we had five gas fired furnaces going (and about the same number of very nervous health and safety guys) all in front of University College London’s Institute of Making.
We’ve also done casting in the deep snow in upstate New York in February (the child in the picture is fine, although he looks frozen he’s not)….
…and pouring rain in the Westfalia region of Germany in November.
Step 3. Finishing
Finishing can be as simple as removing the clay and giving the metal a scrub with a hand held wire brush, to as complicated as cutting, grinding, sanding, polishing, patina-ing, and more.
Here the pieces have been cast and the layers of clay removed.
For some pieces a table with a vise and an angle grinder can be helpful…
…others need smaller tools such as a flexible shaft rotary tool and most need a few minutes on polishing wheels (the yellow wheel in the background).
Finally it’s nice for everyone to get together for a group photo.
Sometimes a very last step is added in which we have an exhibition of all the work that was made.