First Weber lid UDS efficiency = HORRIBLE

I tried my first weber lid UDS yesterday. It was a stubby. 55 gallon drum cut down to 21” tall. Charcoal basket is 16”x7 and sits 1.5” high off floor (I burn lump only so ash is not a big concern) I use a diffuser which is thin steel with 4 legs and it sits over my basket an inch or so. The basket hangs out of two sides of my square diffuser about 2” each side. Temps in center of drum yesterday were within 5 degrees apart. Running 2 slider intakes with huge cfm flow. And Weber lid using stock daisy wheel. Yesterday I used the rest of a bag of B&B lump. Mostly small pieces and a few leftover pieces from previous burns. Basket was approximately 1/2 full. I got a chimney red and dumped them in with some cherry chunks. I let it get going for 5 minutes then loaded the top rack with chicken drummettes. I got fire settled in and held 275 or so for 1.5 hours and removed chicken. I continued to experiment with temps and intake openings before closing her down completely shortly after the game started at 2. All in all I dumped chimney in the basket at around 1130. We ate around 110. And I experimented for maybe another hour running out and looking at temps vs intake openings. So 2.5 hours? Let’s just give it the benefit of the doubt and say 3 for the hell of it. I did check it an hour after closing her up and she had dropped from 275 to around 100-125 so it appears as if she was cooling off fast. I came home today to bring it in the garage for touch up paint and when I emptied it out I cannot believe there was hardly any charcoal left in the basket. This is like nothing I have seen on a drum before. My old stubby with a good sealing flat lid and 2” bung hole exhaust, a slightly smaller square vs round fire basket and this same diffuser, same intakes would run forever on very little lump. Any ideas? I am spontaneous but I am really thinking of going back to what I know and that’s flat lids with a good seal. Can anyone chime in? This sucks and is completely unacceptable.

ebijack said:

You had a very small leak.
Takes time to get a good seal on a new lid.

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I understand but could that really have been all it was? I was excited about using this set up but it’s out of my comfort zone because I’ve used flat lids for eight years And I know what I could get with one of them.

Ebijack is right about the rack advantage. My lid was not perfect as in years past it blew off and hit the road on the way tailgating. But I straightened it and other than looking like crap all over one part of the dome I got it to where it sits flat and flush on my kettle bottom. I did cut my drum with a cutting wheel and careful measurements and a tape line around the drum. It was very sloppy regarding how the lid fit. If I slid the lid to one side the other side almost came off the inside. So I tack welded a piece of 3/32”x1/2” flat stock around the drum. I got it pretty close but did notice a slight high spot at one point which I “milled” down with my 60 grit sanding disc. The lid sits perfect on my Weber and pretty dang nice on my UDS. Not perfect for sure but nice. Bottom line as another person said the flat lid is made for the drum. I am up in the air. It’s possible other factors are at play in my case but I also stated I am out of my comfort zone on this one regarding making decisions. All I know is of the 5 UDS I have built for me and friends using flat lids and anything from slider door intakes to ball valves, both full size and cut down stubby, have been surprisingly efficient using the same drums on all of them ( open head with clamp on lid)

KClandcruiser said:

This is exactly what I did with my UDS. Put foil completely around the lip and when it eventually fell off I just kept motoring on and haven't looked back. Holds temps like a dream now. Just took 3-4 cooks to get it going

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Mine appeared to hold decent temps but I am just shocked at how much fuel I went through. Did yours eat up a hell of a lot of charcoal at first?

KClandcruiser said:

I had more issues with temp control than fuel consumption, but I think that was more of the learning curve on working with a UDS. I think it might have been slightly higher consumption but nothing memorable. I read that you had smaller chunks of lump and whatever was left in your basket, do you think that situation combined with your air leak might have caused it? May just have to bite the bullet and smoke something else :thumb:

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I was hoping someone else would chime in about that cause I honestly don’t know. Does a whole/half basket of small chunks burn a lot faster than a whole/half basket of large chunks? Small chunks pack in tighter and I would think actually you would have more volume of charcoal per same size container. It’s similar to using a set amount of kosher salt in a rub but if you use table salt you use less cause it packs in the measuring spoon tighter with less air between granules or at least that’s what I have always read