Posted by David Eichenbrg on December 15, 1998 at 18:33:01:
You will need 100p.s.i. to make it work.
I am not sure but are you diping your shells into a 1700 degree furnace now? Or are you starting them in a cold kiln and taking them up to 1700 degrees? I work with ceramic shell and do by
burn-outs in a kiln that I designed. It is a gas kiln that goes up to 600 degrees in 1.5 minutes I then let the shells rise in temp to about 1650 or until they are clean, this allows the wax time to contract and flow, I catch the wax in a water pan to reuse. The kiln allows me to currently burn out about 12 shell at a time (say the size of a life size portrait bust) in about 20 minutes. The kiln has a power burner on it. If you are interested in the plans let me know. I would strongly recommend not trying to build your own autoclave machine, but if you do, like you said don't be in the room.
Good luck The 100 p.s.i is from "methods for modern sculptors" The kiln I mentioned above is also nice because of the design we have no fires and little smoke.