Written by Johnny Walter - Thursday, February 4, 2016
Our first article described the creative work of the
Today, we will focus on the work of the model maker, little known and yet essential to the realisation of a jewel. He is the recipient of all technical drawings, gouaches or sketches. His task is to give volume – using material – to the 2D creative expressions. As such, he uses metal (not precious metal at this stage …) or wax (green, red or blue, all depends on the required hardness) to literally carve the jewel.
How? By using all the equipment of a jeweller: a specific saw for jewellery, files (long and flat, with a specific choice of grain, bearing names as strange as « sage leaf » or « rat tail » in French, actually a literal description of their shape), a handpiece mounted on an engine to which a ball mill will be grafted, for example.
So much technical vocab and tools! True, and not so surprising if you remember that jewellery is a craft that uses what is commonly referred to as “the intelligence of the hand“: an extremely precise and delicate gesture!
We must be grateful to these jewellers who master all stages of the jewellery creation,
Indeed, the model has two goals:
– first, the search for the perfect shape of the future jewel. This is the time when the jeweller’s science becomes magic. Indeed, in its effort of technical interpretation, he will propose the best possible shape: it will be perfectly aesthetic, with the exact dimensions, a light and already beautiful object.
It will then be used as a tool for validating the project. The customer will give his approval for the launch of the production according to the proposed model. Once approved, it becomes a prototype.
– in other circumstances, and this is where the model becomes meaningful, it will be used for “lost wax casting”. This technique is not new, the Egyptians used it already! It is also in full swing with the recent development of semi-industrial techniques.
What is the technique of lost wax casting? The validated model will be used to create a silicone mold. In this mold, negative of the initial form, one injects wax as many times as necessary, which one will then graft on a tree (a wax rod to which the copies are weld). This tree and its grafts are then plastered, that is to say that the tree will be placed in a cylinder which has a bottom and then pour plaster into the interior. After drying, the cylinder is placed in an oven. By heating, the wax “disappears” – it is lost! It leaves a cavity which ready to receive the molten metal. Once cooled, the cylinder will be immersed in cold water or oil, causing the plaster to burst.
What is left then? A true copy of our waxes, but this time in metal!
This molding method is extremely efficient and allows to realize very fine and delicate pieces. It is not uncommon, in jewellery, to melt all the components of a piece, then to have them assembled in a workshop by expert hands.
It is possible to produce everything with this technique, mesh, crimps, metal pieces capable of accommodating stone paving, bulky pieces, small pieces, naturalistic motifs, clasps, etc.
However, originally it is the modeler who gives shape to the cast iron. Without talent, lost wax casting is useless…
Some will argue that today 3D printers can do the model maker’s job. Absolutely false! Both methods offer significant advantages, in the case of printers it is the possibility of producing multiple models in one go with great detail. That is not enough however to create a beautiful jewel! It will always be necessary that the jeweller reworks the metal to turn it into an art piece.
The wax model is not always a mandatory step: some jewellers make the jewel directly out of metal, if the shapes are simple, and if it saves time or reduces the number of production stages. This will work very well for unique pieces of jewellery or small series (less than 5 pieces) and will give them rarity.
In France, jewellers are trained in both techniques. They know how to use them at the right time to optimize the production of the jewel and are always attentive to the various stakeholders of the project (a draftsman, a setter, an enamel specialist, etc.).
In our next article, we will look into the jeweller’s profession, he who will give its final shape to the metal. His task will be all the more arduous as the piece is complex.
Johnny Walter –