creation process - Katharina Freitag

You mustn’t torture the material

Fritz Wotruba

The vision for a work comes very directly, often unexpectedly – I act as a medium between idea and matter, beyond time and space, completely focused on form, line, and surface.

It’s a process into which everything I experience, including thoughts, flows – what emerges in the studio is both a result and a part of this experience. Recognizing the moment of completion is essential.

I proceed step by step, often starting with sketches, sometimes modeling directly in clay, wax, or plaster. The goal is the final result in bronze, marble, or glass.

Creation process of the bronze sculpture Attraction

First, a full-size model was built directly in plaster over a metal frame.
At the bronze foundry, the model was separated and a negative mold, a plaster casting mold, was created.

A wax model, approximately 4 mm thick, is cast from the negative mold and filled with refractory clay. This prevents warping. The wax model is then fitted with channels that converge at a raised point; this will later be the pouring point for the bronze. Vents for air must also be included. The entire structure is then encased in wooden boards and also cast with refractory clay.

Now the wax positive, with its channels, is supported on all sides and ready for the kiln. It remains there for two to three days, slowly heated and then slowly cooled, allowing the wax to slowly and completely drain from the fireclay mold. This can vary depending on the size and shape of the sculpture, and the temperature must also be carefully monitored to prevent any residue from charring the wax. The entire wax model, including all the channels, is thus transformed into a hollow space. The fireclay is then fired to a solid and stable state.

Now comes the magical moment of bronze casting. The bronze is heated to approximately 1000 degrees Celsius – here again, the caster’s skill is crucial; the bronze must not get too hot, otherwise soot will form and it will bubble during pouring. However, it must be hot and fluid enough to reach every corner of the hollows.

With intense concentration, the casters lift the casting kettle and pour the bronze into the re-cased fireclay mold until all the cavities are filled. The remaining bronze is immediately poured back into ingot molds, where it cools until the next melting.

After some time, the fireclay mass can be carefully tapped off, revealing the hardened raw casting.

Once the bronze has completely cooled, it is cleaned inside and out. The chaser then removes the channels, grinds down excess edges, welds shut small holes, and welds the individual parts of the sculpture back together.

The final step is patination, where the bronze is heated and a patina is baked into the surface through a chemical reaction with, for example, sulfur.