I belong to a group that has some land where someone built a large wood-burning offset firebox masonry smoker. I think the smoker was built only about five years ago. The build is of high quality, but there are some design problems. I think the original design had some sort of grill (wood? charcoal?) above the fire box in addition to the smokebox.
Here is a link to a bunch of pictures of the unit: http://s275.photobucket.com/user/PianoV/library/TSS%20Smoker?sort=3&page=1
A gas grill was built separate from this unit, so we no longer have any interest in the original grill portion of this unit. As you can see in the pictures, the grill thing is now just a pit about 11 inches deep. The bottom of the grill pit is the ceiling (warped 1/4" plate steel) of the fire box.
If the fire box is adequate (see below), my first question is how to best repair the top of the fire box. The 1/4" plate steel ceiling of the fire box is warped upward in the middle about one inch. Seems to me the best thing to do would be to seal that gap off somehow. Would fire-brick mortar be the best thing to seal it with? It is warped on both sides, so it would have to be sealed to the steel plate on the right that overlies the opening to the smoke box, and on the left side where the steel plate ceiling butts up to a masonry wall.
And then how to finish the top off? Just fill the 11-inch-deep pit with bricks and mortar and maybe topped with three or four inches of reinforced concrete (and maybe tile on top of that)?
And then that leads me to my other major question - is the fire box large enough? I've read that a fire box should be a minimum of 1/3 the volume of the smokebox. The volume of the firebox on this smoker is about 7% of the volume of the smokebox. Is there any hope of this fire box working properly for this smokebox (I have not yet done a burn with this smoker)?
The smokebox measures 49" wide, 41" deep and 99" tall = 200,000 cubic inches
The firebox measures 24" wide, 45" deep and 13" tall = 14,000 cubic inches
I wonder that because the firebox footprint is 24" X 45" = 1,080 square inches and the smokebox footprint is 49" X 41" = 2,009 square inches, perhaps the size of the firebox really isn't so terribly small being that the footprint of the firebox (which means the SIZE of the fire) is a little better than 50% of the smokebox footprint. Keep in mind also that this is a masonry smoker - good heat retention - and the fact that this smoker is in central Florida - the coldest weather we'd likely ever encounter during a smoking session would be about 60 degrees outside - so it's not like we need a humungo fire to heat up a below-freezing smoking chamber.
But then again, that IS a VERY short height for the fire box - yes? I built a much smaller masonry smoker at my home of similar design (offset firebox) and the interior of my firebox is 21 inches tall - almost twice as tall as the subject very large smoker. How will the short height of the firebox affect it's performance?
A third, directly related question is this: if the fire box height is a problem, as long as I need to repair/redo the top of the firebox, I could just get a bit more radical and tear the existing top apart and make the firebox up to 11 inches taller - I could make the firebox a total of 24 inches or so tall. If I were to do that, what is the best construction for the top of the firebox? Would a heavy steel plate be the best thing (maybe 3/8" thick)? I guess I would want to also move the opening between the firebox and smokebox from where it is at the floor of the firebox up to the uppermost area of the firebox (and probably make it smaller - well, size it according to the calculator this site has).
Lots of questions. Hoping for any good input. I think this smoker has a few current problems, but that it also has EXCELLENT potential. Really looking forward to some input. Thanks!
Tampa Bay, Florida
FWIW: I am not a super-expert smoker guy. I built my masonry smoker at my home about 20 years ago and have been smoking mostly pork on it ever since. I'm very happy with the performance of my smoker and have gotten some good experience with it. I have had to make a few small modifications to it over the years to improve air/smoke flow, etc., so I have gained some experience with those issues also. I'm really looking forward to my first smoke session on the subject BIG smoker! Here is a link to a picture of my smoker at my home: http://s275.photobucket.com/user/PianoV/media/Ham%20Turkey/P4150009.jpg.html?sort=6&o=1