Albert Mitchell

I could insulate the top half of the tube inside the secondary chamber. Don't know that it would do much good. It may keep the heat in the chamber allowing secondary burn. I could also insulate half the tube on the back side to still allow visible flame.
I think I need to do a small scale build to see how it will function.

That is basically where I got the idea. But with a mass and a heat exchanger for water heating I was trying to reduce how much floorspace I'm using

I didn't plan on insulating it.

I am trying to develop a heat riser that can be seen and is made of quartz. I wonder if it would work to have the drum size reduced and elevated away from the mass. Basically I would have the J tube and on top of the J tube I would have the drum to collect and condense the un-burnt fuel it would act as a secondary burn chamber then fall to the mass eventually leaving through the chimney. the only thing I foresee as a problem would be keeping it hot enough since the tube will not be insulated. I would expect it to function the same I would just have the heat riser exposed on the bottom half.

Any thoughts?