Well, since were bumping for newbs, I figured I'd throw out another option for folks trying to even out temps in offsets. It really might be worth trying out if you are into experimenting a bit. The idea didn't come from me, it came about by reading up on how Jambo's were designed. I've cooked 5 times with this mod (each with full loads of multiple briskets or other meats), and am still quite happy with it. Here is a link to the original thread:
http://www.bbq-brethren.com/forum/showthread.php?t=232977
This idea should work in principal on other offsets.
Here was my thinking: Most offset direct flow smokers tend to give bottom heat to the meat once a draft is established, at least mine does. I had regular baffle plates on my Peoria, and it seemed to move the hot spots around, but not so much get rid of them. While hot spots can be helpful, they got in the way when cooking several briskets at once. I experimented for a while with different plate positions, struggled with some burnt bottoms, and dealt with fat smoke from grease hitting the hot baffle plates. I wasn't looking forward to experimenting with drilling multiple holes in 1/4 inch plate (like the horizon plates have), so that led to trying the current plate I'm using.
I cut out a plate out of thin sheet steel (12 bucks for a 12x24 sheet) that basically forces the hot air straight up to the top of the cook chamber as soon as it leaves the firebox. Once the heat fills the top of the smoker, then the hot air all drops down over the meat very evenly left to right, as it finds the exhaust stack.
This method will concentrate the hot spot very near the firebox, so you still lose a little bit of cooking area. However, what you lose is really not that much (Maybe 6 to 8 inches of my total cooking area, which is 48 inches long. The cooking area that is left though, has been very even, and all top heat which does not scorch when you raise the temps. I also don't get any grease smoke from stuff dripping down on hot steel.
Here are a couple of pics, the rest are in the linked thread. Hopefully this could come in useful for someone.
Looking into cook chamber towards the firebox, No plates:
Same view, but with the new 22gauge sheet, which sits about 4 inches away from the firebox opening:
Here is the sheet by itself. It's easily removable for cleaning the bottom of the cook chamber, because it just rests on the rails that previously held the 1/4 baffle plates that it had before. The little tabs on the on the sides of the sheet keep it from falling over.
