Some of the construction details are worth a glance.
I'm now using the inner part of a wire mesh roll, rather than cutting up and rerolling a tomato cage. This part of the roll is already in a nice cylinder shape, needing only a little circumferential compression to fit the chimney. There are a lot of ways to achieve this. I'm mostly using hooks bent from heavy copper wire, as it is easier to work with than the even thicker steel wire.
The two wire cylinders are held in place in the wire channel by a combination of gravity, friction and mechanical interference. Good enough for now, and easily undone. I've also loosely attached this handle:
It is slightly below the center of gravity, so it takes a second hand on the chimney to keep it stable. It felt surprisingly solid, carrying it from my workshop to the garage, but I wouldn't want throw it into the back of a pickup.
The burn chamber is still joined to the chimney by just jamming them together and stuffing cracks. Still ugly, but tighter than before.
It's raining today, so I don't think I will get a chance to run it. At this point, I would be very surprised if it doesn't run up to 900˚ pretty easy. Aside from working out these incremental improvements in my construction methods, I want to use this BOOH to run some tests on how various things survive in the burn tunnel and how they affect the batt material. Plus fuel and air intake geometry.