Wax casting is an ancestral technique, very precise. Most of the time, this process is used for our jewelery because we can work wax by sculpting, modeling, engraving... This stage of wax design is a must in the Tournaire manufacturing process.
We also use another technique. Indeed, we were also one of the first jewelers to build on 3-D design in 1997, with a 4-axis 3D numerical control. The ideas for the creation of a jewel are always born on paper, they are then translated into 3 dimensions on computer. The representation of the jewel is then transmitted to a 3D printer which, by successive layers of wax, will create the matrix of the jewel.
We appeared as UFOs initially in the world of jewelry using 3D. Today almost everyone uses it. At the beginning, we were told that it was not jewelry, but we must live with its time: the stone sculptors no longer use the hammer and chisel. Even with the computer, it is the head that controls the hand, which controls the mouse. If we give a pen and paper to the gentleman, he will not write Victor Hugo. With 3D it's the same, without the creativity and the knowledge of the technical constraints, one could not realize anything.
We are lucky to have a good knowledge of the workshop, it is not enough to know how to draw beautiful jewels, we must also know the technical constraints to realize them.
Other processes exist, such as forging, cutting, riveting or welding; To make a model directly of metal which can be molded in rubber in order to be able to make replicas. The mold will be cut in two parts to remove the model, there will remain only the imprint of the jewel. We can therefore inject wax into the mold, which will allow us to obtain wax models for cast iron. Various modifications can be made on waxes before casting. For example, it may be possible to find operations for trimming a ring in order to adapt as best as possible to the finger of the client.
This stage is very delicate, each defect remaining on the wax will appear on the metal, so it is necessary to make a very good preparation of its wax.
The waxes are mounted on a tree called a "wax tree". Once all waxes are installed, the tree is ready to be "plastered". This step will make it possible to create a cylindrical mold, the "cast iron cylinder" made of refractory plaster comprising the shape of the "wax shaft" in negative to accommodate the molten metals.
The precious metal is first heated in order to reach its melting temperature and to pass to the liquid state. The cylinder with the wax shaft is previously heated in order to make the wax disappear and to avoid a thermal shock during the casting of the molten metal. During the casting of cast iron, the liquid metal takes the form of the "wax shaft" in the cast iron cylinder. After cooling, the cylinder is broken in order to release the "cast iron shaft", and then the plaster is finally removed by means of a high-pressure water jet.