I had some trouble trying to get the smoker up to temperature with just one damper going from the fire box to the smoke chamber. The solution was simple, just add a second vent damper from the fire box to the smoke chamber, I also added a damper to the smoker chamber outlet. I had to order two more damper collars from Vogolzang, which are $18.00 bucks each. Once I added the second collar I can run the smoker from 140 up to 400. Not that you would want either of these since most of the time you smoke from 180 to 225 and roast about 300 to 325 but its there if you want it.
One other thing you should do. The piece of barrel that you cut out of the top barrel makes a great heat defuser. Just drill some holes in it and place it in the top barrel over the vent from the heat box. Place it in there with the curved side facing up. It makes the temp in the smoker chamber even all the way across the grills.
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