The Texas BBQ Forum

I am currently building an offset smoker (will try to get pics posted of current state)

details:
250 gal porpane tank, already cut doors open and attached fire box
used weld on hinges from trqctor supply, seem to be working well
plan to have slide out lower cooking racks, looking for ideas here
also plan to have racks above, may or may not slide out, pros/cons?
used 4" pipe nipples with caps screewed into fittings on top of tank for door stops
What size smoke stack should I be using? some have told me 6". sounds to big to me
my fire box is a 20" dia 3/8 wall pipe section 24" long. too big?
whats the best way to close the end and make door and damper(s)
is a big fire burn out inside the tank really necessary? if so, at what point should I do it? before paint i assume.

Well, I'll stop the questions here for now, but I have many more

Ideas? Sure I got some...

What is the diameter of your tank? 250gal tanks can come in a variety of sizes... If it's at least 24", I would def. go no less than 2 levels of sliding food grates. 6" pipe would probably be just about right too... You can always damper down an exhaust that is too big, but the reverse sure ain't true. Exhaust stack height can also effect draw through the pit.

I would def. burn out the pit if you haven't already. LPG stinks and a good burn can help you get any remianing residue out of the tank. Then I would scrub it with dawn detergent real good and season it with lard.

Once ya get some pics up, it will help us with door suggestions.

Well, its a 30 inch dia. Forgot to mention that.

I agree with what James said.

Ok.
here are 6 pictures of the build so far

tank is 7 foot 9 inches tip to tip and 30 inch dia

fire box is 24 inches long and 20 inches dia 3/8 wall

Lookin' good. gonna be a nice pit when you're done.

well, only 3 of the pictures are showing up so here are the other 3

That's a nice looking build you've got going on there... While I prefer square fireboxs, there are several pit builders who prefer round. Check out Gator Pits (www.gatorpit.net) and take a look at how he does his doors and intakes. Looks like he just cuts a piece of plate to fit the pipe, cuts a door into it, welds it up, cuts holes for intakes and uses bolts and plate to create the adjustable air controls...

I know that Bluz used this method on his most recent pit build, maybe he will jump on here when he sees this and tell us what he did.

Here is one example of a Gator Pit w/ round firebox.
http://www.gatorpit.net/trailer_pits/im ... iner_2.JPG

I agree with what has been said so far, I totally agree with the 6 " exhaust. I want to say one thing though from your pics and I looked at them again to make sure what I was seeing m before I said anything, when you do your burn you need to monitor you temps and how fast it gets there as well as how well it will maintain the temps. Reason for me saying that it just looks to me that you may be starving the firebox of much needed exhaust, directly from the firebox. It may just be the way I am looking at the pics so forgive me if it is. I have had very good success with my builds having a larger area to expel the heat and smoke from the firebox to the cooking chamber. You may be fine with it, but again just monitor those temps and you'll find out if its right or not.
My 2 cents
Btw when you do build that fire, toke it very hot and much of that paint and rust on the outside will either flake off or will be easier to clean afterwards.

I actually intended to ask about the size of the opening between the firebox and cook chamber, but I got off on that other tangent.

Got any measurements or pics of it? Are you going to use tuning plates or are you going to build it as a reverse flow?

Also, back to burning it out. I'd probably throw two or three big bags of briquettes in the bottom of the cook chamber and light that off... Should get hot enough to burn off the nastys and as Bluz mentioned a lot of that paint and rust...

wel, the opening from the fire box into the smoker tank is a little larger that the prifile of a football.

I dont have any idea what a tuning plate is. I am not planning a reverswe flow smoker.

ok, i just went out and measured/
shape is that of a football, 15 inches long and 7 inches high

In a traditional offset smoker tuning plates are used to control the way heat and smoke migrate through the cook chamber. An easy way to envision the way that heat and smoke will move through your pit is to picture it upside down. Water enterign from the firebox side. With no baffles or tuning plates, the water will quickly poor to the top of the pit (remember the pit is upside down. It will flow over to and out of the exhaust stack. This would essentially mean that the majority of that heat/smoke would go right over the top of any food you may have on the grates.

Tuning plates are just that, plates. The start out on the firebox side of the pit and progress to the exhaust side with gaps between each plate. The gaps start small on the firebox side (where the heat/smoke are hottest) and gradually get larger as they move they get farther away from the heat source. With these plates you can "tune" your pit to get a more even temp across the entire cooking surface.

Check out this link with pics that might help to explain it better.

http://www.bbquepits.com/images/ACCESSO ... PLATES.htm" target="_blank

The other thing I would suggest is that you extend your exhaust stack into (about the middle) of your tank. This will also help with temps etc.

jedeuce1 wrote:ok, i just went out and measured/
shape is that of a football, 15 inches long and 7 inches high

That may be plenty big enough, but only way to tell is a test burn once you get the exhaust stack in place. One of the more experienced pit builders (I ain't one, I just cook ) can give a though on it.

yes, i plan to have the smoke stack exit at about middle line of the tank.
I see the pics of the tuning plates........ wasnt planning anything like that. Is it a must have or just a nice to have.

also, I was my understanding that in an offset smoker, the fire box is offset much lower to get the heat started out low in the pit. and a low exet point for the stack also helps