Basic UDS specs?

Discussion in 'Charcoal Smokers' started by new to q, Feb 16, 2009.

  1. I've skimmed over the amazing pic tutorial Norcoredneck did at the BBQ Brethern forum, but I'm still just looking for basic universal measurements and whatnot. You know, just a simple list of where to drill this or where to drill that. Also, I've noticed that some people have 4 intakes on the bottom of the drum while others only have 3.

    How much of a difference will that make? Also, for the intakes I see that most only have a single valve ball on one intake with caps for the others. Wouldn't it just be easier to install valves for all of the intakes? I really don't know what I'm doing here so any advice would be appreciated.
  2. jdoe44

    jdoe44 Fire Starter

    With just one ball valve you can still get infinite control. With the valve completely open it should allow the same flow as one nipple off, so you can use the valve to meter air up to one full cap off, then close it and take a cap off and use it to meter air up to 2 caps off, then close it and take a second cap off and use the valve to meter up to 3 caps off.
  3. waysideranch

    waysideranch Master of the Pit OTBS Member SMF Premier Member

    I drilled my intakes up from the bottom around 2". The grate bolts are around 8" from the top. Charcoal basket sits up 3" from bottom of drum.
  4. ddave

    ddave Master of the Pit OTBS Member SMF Premier Member

    Norco's post really spells it out but here is a summary.

    Intakes: Three 1" holes 2" from the bottom. A 3/4" nipple will thread into a 1" hole.

    Charcoal Basket: Coal grate from a small (18.5") Weber. The grate is actually 13.5". Expanded metal sides -- 44" x 8" #9 3/4" rolled around a propane tank and wired (or bolted) together and wired (or welded) to the charcoal grate. This will hold 18 pounds of charcoal. Plenty to do a brisket. Way too much for most other things. Three 3-1/2" x 1/2" bolts for legs to keep charcoal grate 3" from the bottom of the barrel.

    Cooking grate: 22.5 replacement grate for Weber. Cook grate height should be 24" from charcoal grate in charcoal basket. About 27" from bottom. Distance from top will depend on height of drum.

    Exhaust: 2" bung hole in lid or eight 1/2" holes equally spaced around the perimeter of the lid. This may help with the layout.

    You can use three valves for the intakes but they are WAY more expensive than caps, stick out and are not really necessary.

    Here is a link to how I built mine. Certainly not the only way, just the way I did it.

  5. hog warden

    hog warden Smoking Fanatic

    When cooking with a UDS, what happens to the grease/fat that melts off your meat?

    In my Brinkman smoker, it falls into the water pan. In any other BBQ, it burns on the charcoal, or flavor bars (gas grill) or drips out the bottom.

    Anybody remember the old Safari grills? The only fuel was a couple sheets of wadded up newspaper. You put your hamburgers over those and the fire from the newspapers started the fat dripping, which became a roaring grease fire that finished the job.
  6. ddave

    ddave Master of the Pit OTBS Member SMF Premier Member

    Most of it falls into the hot coals, vaporizes because of the heat and creates an amazing aroma. A small portion falls outside the charcoal basket and ends up in the ash pan or on the bottom.

    You don't really have to worry about flare ups since the amount of air is so tightly controlled -- unless you have a leaky drum. When I did the chicken quarters, there was a lot of grease in the coals. It flamed up a bit when I took the lid off and the flames died out when I put it back on. but since the cooking grate is about 24" from the fire, the flare ups didn't hurt the meat at all.

  7. Dave, that's exactly the kind of quick write up I was looking for. I really appreciate it. I have just a few more quick questions if you don't mind. The lid to my drum already has 3 holes with caps that I can simply unscrew for the exhaust.

    I guess what I'm asking is do most UDS owners prefer their exhaust this way or the 8 1/2" holes around the lid? Does one way provide better smoke ventilation than the other? Also, should I place anything under the charcoal basket to catch the ashes or will it be ok to let them fall onto the bottom of the drum?
  8. rickw

    rickw Master of the Pit OTBS Member

    I used a 2"x6" black pipe nipple and screwed it into the large bung hole and it does a great job. One advantage to this is you can just throw an old tin can over the exhaust and keep the rain out.

    I also don't use an ash pan under my charcoal basket.
  9. ddave

    ddave Master of the Pit OTBS Member SMF Premier Member

    From what I have read in other forums, I'd say it is about 50/50. A lot of people just use the openings in the lid and a lot of people drill multiple holes in a circle. Not always 8 1/2" holes -- some use larger holes or less of them. I believe the BDS company builds them with 8 1/2" holes which is probably why that configuration got so popular.

    I think the theory is it helps even out the temperature across the grate. Some users with a single exhaust report that it creates a hot spot so they will rotate the lid. Other single exhaust users report no problems at all.

    That is entirely a matter of personal preference. I think it is easier to clean out with an ash pan. But you don't have to do it that way. I just found that when I went to dump the ashes after smoking an 8 pound pork butt, most of the ashes stuck to the sides of the drum and it was kind of a pain to get it cleaned out. It is certainly ok to let them fall onto the bottom. Just be aware that they will tend to gather moisture so you will want to remove them after a smoke so that the bottom of the drum doesn't start to rust.

    Hope this helps.

  10. DDave and RickW, thank you for all of the information. I probably wouldn't even be attempting a UDS if it wasn't for the advice and help from members like you. I hope to start the build this weekend. I might even post some pics along the way if my mind remembers to remind me. [​IMG]

    I’m on dial-up out here in the sticks though so I’ll see how that goes.

    Thanks again.

    - Brian
  11. rickw

    rickw Master of the Pit OTBS Member

    It's a labor of love and you will love the way these drum smokers make Q.

    Follow the basic design found here and all will be well. There's a great bunch of folks here to learn from.

    Pics would be nice.

    Good luck on the build.

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