Well I'm chuffed. Home-made charcoal burns nice and hot. I took it all apart this morning and found big globs of melted aluminium and lots of cans with the paint burnt off.
More importantly, I've sold some unwanted stuff on ebay so I now have a nice large pay-pal balance to spend on modeling clay. The next few weeks will see me working on the mold side of the process and then building the furnace.