UDS Build Newbie Questions

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Original poster
Mar 4, 2011
Hi all, just joined.  Been reading a bunch of threads but still not clear on a few things and would appreciate some advice rather than trying to find it though repeated searches.

I have a buddy going to line me up a 55 for my UDS build.  I picked up a bunch of stuff already, but want to make sure before firing up the drill.

I want to use the flat drum lid (no dome) and I want 2 racks, top one being for ribs, bottom for something bigger (butt, shoulder, chicken, etc) or more ribs.

Biggest concern is location of racks.  I really need to optimize space to make sure It can burn well, not be too close to fire, and have clearance between racks and between top rack and underside of flat lid.  I'm probably over-thinking all this regarding the measurements, but once you drill those holes, you're kind of stuck. So would appreciate thoughts. I promise to follow up with pics and credits :-)   So....
  1. Should I go with widest fire basket (i.e. weber 18.5 charcoal grate) in order to keep the fire lower than if I used a smaller diameter (i.e. 13.5 grate)?  I'm thinking that if I make it widest, I can keep the expanded metal height down to 8".  Then I might be able make by bottom rack say 23" from bottom of fire grate.  I'm not sure why it has to be 24" if you're not planning on stacking 12" of coals. If I'm only stacking max 8" of coals, doesn't that technically give me 4 more inches of play because the fire itself won't be as high?
  2. Can I do coal grate 2 1/2" off of floor?  I read people having issues with 2" and when they moved to 3" it was better. Well how about 2 1/2" to gain a 1/2"?
  3. Would 5 1/2" between cooking grates be enough for a butt, shoulder, etc.? I'm hoping this leaves me with about 2.5" clearance to top flat lid. In summary if a barrel is 33.5", then coal grate will be at 31" (-2.5) to top of barrel. 1st cook grate at 8" (-23) to top, and finally top cook grate at 2.5" (-5.5) to top.
  4. Am I overly concerned about having 2+" clearance on first rack with a flat lid.  Again, I only want to do ribs there.  Is that enough room to cook ribs and not have them hit the underside of lid? 
  5. What is max thickness of a slab of ribs?  I figure they could be almost 2" via they're natural bend, but I don't have a rack in front of me to check.
If the 24" is a must do (regardless of top height of fire basket), then I guess my only other option with a flat lid is to have less space between cooking racks.  I guess I could separate them by 3.5" and that gives me plenty of clearance, except that I can only do ribs, sausage, etc. and won't stand a chance of doing something bigger on bottom rack, when using 2 racks at same time.   So let me know if my squeeze attempts listed above will work.  I could also probably go with a 3rd rack for water, but I'd like to avoid that if possible.

Other questions...
  1. My drum will probably be from transmission oil.  Is this safe to use after a burn off or two?
  2. My buddy said these lids may have some rubber on it for tight seal. Does this need to come off or can it stay on to get the tightest lid seal possible when smoking? I read someone else having an issue with a seal there, and a recommendation was to add inner tube rubber. My friend was thinking we needed to get it off (burn, etc) but I don't want him jumping the gun if any rubber on there should stay on. Also don't want it melting on my meats :)
  3. I'm planning on 2 x 3/4" holes (.75" bit) closing with magnets, 1 x 1" valved (1.25" bit).  Should be fine, right?  Is the 1" overkill, or should I stick with 3/4" (1" bit)?
  4. Plan on putting threaded nipple and elbow for valved intake, and then go PVC from there.  Also plan on threaded nipple to PVC for vent.  Any concerns with PVC?
  5. Plan to paint with engine enamel and rustoleum plastic paint on PVC.  Should be okay?
  6. Any concern with zinc coated bolts inside?  I thought I read it shouldn't be galvanized, but then I just read something about zinc.  And don't want to spend on stainless.
Thanks in advance.  Sorry for the length, but figured I get it all out there in 1 shot rather than intermittent posts.

And thanks to everyone who posts here for getting me started! Can't wait!
I would personally go with the wider charcoal basket. I have had issues with the outside of my drum being a little cooler then the inside of my drum but once I got a wider basket that pretty much went away. I believe my grates are set at 3.5" from the top and 8" from the top. 3.5" is perfect for me for doing ribs or wings on the top rack while cooking brisket or butts on the bottom. I wouldn't go any less because I have issues now with not having enough room for my ribs when I foil them. If I get carried away with the foil the lid doesn't want to close.

You need to get rid of that rubber sealer on the lid. Also I wouldn't personally use the drum if it was filled with toxic stuff but then again I am able to get food grade barrels where I live for $25. There are plenty of people who have used toxic drums and made them into a UDS you just have to burn them really really good and many even pressure wash them and then burn them again.

I went with (4) 1" intakes on my drum and I have never wished that I had smaller ones. So 3/4" or 1" either will work.
Sheesh I almost forgot about the foil.  So if you are 8 and 3.5 from the top, that leaves 4.5" between cooking grates, right?  That's enough for brisket and butts?

I'll defintely do a double burn then, and maybe a pressure wash in between. I was reading a little on tranny fluid and it's much like oil as long as it's not used fluid. Used oil is when it gets toxic with heavy metals, lead, etc.

I have never had an issue fitting a butt or brisket between my two grates but I suppose if you got a big enough one it could be an issue.

The best thing I have seen lately was someone put adjustable grates in their smoker. Basically they put 3 shelving brackets down the inside of the smoker then you use the little peg legs and move them up and down in the smoker for what ever height you want your grates to be at. The next one I build will have that. That way if you are doing ribs only you could put 3 or maybe even 4 (probably pushing it with 4) grates in the drum since they are very thin.
Ken,I remembered (I think it was Sloflaker), that had another barrel(just one section,including the little flare.
 It becomes a lid when you can't find a Webber lid. You then have no trouble with size

However you do it , remember to always,
BBQKen, Good afternoon. If there is a label on the drum, you can check on the web for a MSDS. Or get a MSDS from the transmission shop. That should tell you everything you need to know.  
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