I finished my UDS and started the first load of charcoal. To my surprise 20 lbs. KBB burned at minimum of 250f for an amazing 30 hours! I spent the day messing with temps so it was all the way up to 350f for a time. I had the fire box made by a friend in exchange for two pork butts. Has anyone gotten that long of burn times?
Here is a picture of the box. 12" square by 12"inches deep. Four inches between the bottom of the box and the ash pan. It is a bit heavy but it is solid.