This is the bucket that I chose for my furnace project,  with hindsight, it is far too small, it doesn’t leave enough room for insulation refractory, perhaps next time I’ll use something custom made. To this container I added some cheap bolts and galvanised steel wire to lock the refractory into place. The legs were made from beam hangers and other heavy gauge steel I could buy from my local builders merchant.

The refractory is a special high density version rated to    1600 oC.

Once the refractory was tamped arround the central former ( plastic paint tin ), the whole lot was wrapped in bubble wrap along with a wine heater and left for a couple of days to cure, the former was removed and the heater was placed inside the cavity and left a further week, when unwrapped the whole thing looked and felt as dry as a bone, this is not the case, all cements chemically bond water into the structure and when you fire the refractory cement this water is released,  YOU MUST FOLLOW THE REFRACTORY MANUFACTURERS HEAT UP SCHEDULE. Even doing so the whole thing hissed like a pressure cooker.