I've been playing quite a bit with the bone and charcoal process lately on scrap and test pieces. Warpage is a concern and critical parts need to be blocked before the process is started, but it is not really difficult. All of my students do this process for the baseplates of the steam engines I have them build. We just bought a larger heat treatment furnace from Brownells, but used the smaller furnace from there previously. All charcoal is purchased from there also. Here are some pictures of the procwss and finished parts.
Alex,
Thanks for posting the pictures. Most people have not seen the actual process before. Next time you are need a new "furnace", look for a used ceramics kiln. I know a couple of commercial operations that use them.
Are you preheating the bone charcoal?
Pete
