Originally posted by Dave Russell:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TravisH:
Technically, Stefan's barrel isn't sitting flat with "no gap at the bottom" as air is coming up between the deck boards.
True, but you don't need any air coming under the drum. Lots of guys make their UDS with an "old man intake", which is an elevated pipe intake that runs down to the bottom of the drum. The idea is that you don't have to bend over to adjust the vent, and more importantly, you don't spill your beer. They commonly use a ball valve, and I hear it works great as long as the pipe is sufficient in diameter (about 2") and doesn't run all the way to the top of the drum.
More importantly though, I wish I would've left my plastic drum the way I originally cut the bottom out with the wide lip left, cut around where there would be just a little room between the dome and edge of the lip after putting the drum back over the cooker ( barrel upside down). Sure, I couldn't lift the dome off, but I couldn't open the door or adjust the vents very easily without lifting the drum off, anyway.
I did a rib cook like this and was very impressed. Couldn't leave well enough alone though, and I cut the lip off and the drum lost all rigidity, warping real bad after my butt cook last week. Now, I plan on buying another one and just cut the inside of the bottom out like the first one. It really helped save fuel, and the wind was no issue, so taking the barrel off to adjust the vents wasn't needed once I got my temp where I wanted it. </div></BLOCKQUOTE>
Regarding using a drum as a WINDBREAK, I now feel totally different about my first statement regarding not needing any gap under the drum. YES, you do want some gap. It seems like a slight vaccuum of sorts is caused by the wind going across the top that must inhibit intake at the bottom. The reason I didn't realize this at first was that there was very little wind, and I was using the drum more for charcoal conservation in the cold.
Regardless, it'll warp if you don't leave a good lip around the bottom like I did at first. I've been using my old split metal drum (UDS) but I want to get another plastic one before next winter. I'll just be sure to leave a wide lip in the bottom so they'll only be a small gap between the dome and the inside edge of the lip that's left when you cut out the bottom. The bottom will be supported on blocks to leave a sufficient air supply, but not only will the drum block the chill of the wind on the cooking chamber and direct flow into the coals...there will be a lot of insulation to the cooking chamber since there's only a small gap at the top. Think of it as a cheap hard-shell plastic smoking jacket.