This is going to be a picture post! While documenting some of my work this past Wednesday evening, I happened to notice that the instructor in the jewelry class was going to cast something. So I followed him around. Here he is gabbing an invested flask out of the burnout kiln. The flask is made from half a soup can, contains a mixture of plaster and silica flour, and used to have a wax ring in it, which has since had the wax melted out:
The next series of pictures is loading the invested flask onto the centrifugal caster. This is an arm attached to a spring which is wound up and, when released, will spin around. The metal (silver) will flow from the crucible into the flask. Centrifugal force is needed because the hollow parts in the mold are too tiny for metal to flow and air to escape with just a gravity feed. The very last shot is the ring!