Thanks for sharing your video on casting a burn chamber. It inspired me to start experimenting with building one myself!
I would be interested to hear more about how you cast the heat riser as well! I imagine it would have to be done after the core has been installed? Or put in place (home, greenhouse, wherever)? How do you ensure the stability of the riser on top of the burn chamber? It seems like it would be unstable without something to act in place of rebar?
Finally, Have you noticed a significant performance advantage in your 'cast heat riser' over the 'perlite and clay slip' that Evans & Jackson discuss in their book?
Any input is much appreciated!