Yesterday I was able to source some 190mm diameter cardboard tube for free, which will make a perfect vertical burn tube size. Today I’m drawing up the dimensions for the concrete mould, and I found out I can get a 25kg bag of high temperature cement for $40, which should hopefully be enough for the jawb.
Now to make the mould dimensions, and get it made.
So the base of the mould is 2 sheets of ply thick, then there’s a bunch of stuff going on on top of that. All these cut off’s will go on the bottom, to create an air gap for thermal insulation on the bottom.