Hi folks,
I finally got a chance to do some more controlled tests with this stove. I sealed around the door frame with black carbon felt as a gasket and used 8' of six inch chimney pipe. For fuel I used a twelve pack of small compressed sawdust firewood bricks. I started the fire at 4:15pm. It stopped smoking and the flue gases were clear within 5 minutes. The barrel top hit 760 degrees within 25 minutes and the pizza oven hit 600 degrees (during prior burns the pizza oven only got to 500 degrees)..
Interestingly, using regular firewood in the past, it was burned down to ashes within an hour and a half.
I walked away and made dinner after an hour, but when I came back after two and a half hours the barrel top was still 300 degrees. I opened the firebox to find the compressed sawdust logs still burning and only half consumed.
In retrospect, I think my black carbon felt gasket around the door frame may have limited the primary air entering the firebox, slowing the burn, because I noticed some smoke when I walked away after the first hour. I'm going to have to take a closer look at that tomorrow.
After two and a half hours:
I threw in a small piece of cherry firewood and barrel top temp got back up to 470 degrees.