FROM WAX TO METAL ?
The lost wax technique is one of my favorite techniques. Starting from an idea that I materialize first on paper then I attack the piece of wax still raw. It took me a while to “format” my brain in a way to understand the mechanics of the transition from 2D to 3D. The sculpture on wax can be compared to the sculpture on wood it is necessary to anticipate to remove the material little by little and to make appear the desired forms.
Then two choices are offered to us , either bring the sculpted wax to a foundry who will carry out all the steps listed below or equip yourself in your own workshop. Unfortunately, doing this yourself represents a significant cost. I set myself the goal of being able to make my lost wax pieces independently one day! 😉
Lost wax is a process in which the molten metal replaces, by melting, a wax model placed in a mold. This method is known at least since the fourth millennium BC. J.C Nahal Mishmar, Palestine, has found lost-wax copper objects dating back from this period.
What is the advantage of this technique?
It allows the casting of complex parts in one piece (without soldering) with great precision in the details.
Step 1: Realization of the first piece. A wax model made by hand,
Step 2: The mold: It is the footprint of the model and is made of rubber.
Step 3: Liquid wax is injected under pressure into the rubber mold
Step 4: The assembly: the waxes are then arranged around a heated rod, to form a casting tree. The wax tree is then placed in a metal cylinder.
Step 5: The investment: The metal cylinder is filled with a plastery mixture. It is then placed in an oven to be cooked. In this way the wax tree will melt and flow to leave only the imprint of objects.
Step 6: The casting: The cylinder is placed upside down and then the molten metal is poured inside: the metal must come to occupy exactly the place of the wax.
Step 7: The metal shaft: Finally, the hot cylinder is immersed in cold water so that the plaster breaks up and the metal shaft can be recovered.
Step 8: Deburring is the step of removing the casting rods from the cast iron shafts.