Originally Posted by Foxfire
If I get what you're after, you want to use part of a second drum as the lid for your current UDS which will add some height when in place, yeah? Kind of like using a Weber lid on top of a UDS but instead you're using a second drum, so your "lid" will have straight walls and flat top.
If so, and you don't want to mod your current UDS (so you can continue using your current flat drum lid when you choose to), I'd imagine your best chance would be to take drum #2 and do whatever you have to to open the bottom... turn it upside down, cut off the bottom, etc. I'd then use some thinner gauge metal to make a long strip perhaps 7 or 8 inches in height and long enough to go around the inside circumference of your UDS. Weld or bolt it to the inside rim of your "lid" drum so maybe 3 or 4 inches extends down and can slide into the open top of your smoker. you may need to use some high temp silicone or other sealant to get rid of air leaks on your extension lid. Fine tune with a rubber mallet and I expect you'd be good to go.
Speed is a good thing when getting into, and out of a UDS IMHO...the more unwieldy you make the lid the more "farks" will be involved in getting it on and off :-). Unless you can hinge the extended lid.