I came across this nice lost wax tutorial and thought I would re post it on my blog since it is excellent reference info.
THE LOST WAX CASTING PROCESS
The lost wax casting method involves making a wax model, investing it in a mold, and then melting the wax out of the mold to form a cavity into which a glass replica can be cast.
Wax models can be made in several ways, ranging from hand modeling with beeswax or a similar easily molded wax to casting from a latex or other master mold. Wax can be poured into a pan to form sheets which can then be cut and formed.
Regardless of the method used, the creation of the wax model is the first step to using the lost wax process. Once this model has been made, it should be encased in the investment material (usually a plaster/silica mixture).
Once the investment dries, the wax should be removed from the model by inverting the mold over a pan of water and heating it to about 225 degrees F. The wax will drip out into the pan. Be careful not to heat much above this temperature and don't allow all of the water to evaporate. Since wax is flammable, it can catch fire if it is allowed to get too hot.
After the wax has been melted out, the mold is ready to be cured and fired as described in the main body of this chapter. As the glass pieces melt in the mold, they will fill the spaces once occupied by the wax, a process that gives this technique its name.
With careful reclaiming, the wax can be used again in a later project.