note: I plan to create more detailed posts of the specific fabrication techniques I use in working with the lost wax technique for those who are interested. This is an overview of the lost wax process that I am currently using. This process has and will continue to evolve, however the fundamentals of: model making-investment-burnout-cast-finish, remain the same.
Working with wax to work with metal?
I cast my first silver ring as an art major at Michigan State University in 1986. I have been hooked on the process ever since.
The 'lost wax' technique of casting involves:
- Coming up with a good idea (the most important part of the process really).
- Making a model of the idea/design out of something that will 'burn out' like wax or plastic
- Using the model to make a mold in a plaster based material called 'investment'
- 'Burnout' to create the actual mold.
- Filling the mold with molten silver
- Finishing and polishing the design
The first step in the process is coming up with a decent idea. I outline some ideas on the creative process
in a post here.
Often, just sitting down at my wax bench, with my 'stuff' around me is enough to come up with some ideas. I try to always keep my eyes open for interesting materials from which to make models. Having a good supply of these 'raw materials' is a great way to incubate ideas.
After using wax and other objects to create a model of an idea, I attach a gate.
The gates are seen here as the long red/pink 'tails' attached to the models. This is how the molten metal will flow into the ring design once it is invested.
Next the models are connected together or 'treed' so that many designs can be poured at the same time.
The trees are placed in flasks.
Investment is poured over the trees.
The investment is partially cured and then placed in a kiln for a 12 hour burnout cycle to create the mold the silver will fill.
Finally the molten silver is poured into the mold. (I now use a full face shield, leather apron, long pants and leather boots when casting!)
The trees of rings are then cut lose.
Casting success can vary, sometimes only *60% of the casts fully fill other times most designs successfully cast. There are many variables, each cast I make with my new setup I improve.
The rough casts are then, filed, ground, sanded, tumbled, polished, patinaed, and cleaned before they are ready to be worn.
* Update: With the new casting machine, casting success is now well over 90%!