360 gallon reverse flow build

[bmoore]

After many years of talking about it finally getting started on my dream smoker trailer. Cooking a whole hog on it on August 25 and hopefully a practise hog before that. Couple questions have come to my mind so far.
Will it cause a problem with air/heat flow if I have the fire box to smoker opening not in the center of the fire box? I would like to have it offset so I can put a warming chamber on the back side.
Would I be better making it a rear mount since the tank is so long?
Any problem bringing the chimney off the side rather than directly on top? I would like the door to be as big as reasonable to make loading/ unloading of hog easier and the chimney will be in the way when I open the door if it is on the top.
Fyi smoker dims 38" dia x 73" fire box 24"dia x 61"
Thanks will post pics

 

[bmoore]

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[daveomak]

Bmoore, evening... I'm not sure if I have this right.....  Slide the yellow tank under the smoke chamber and place it where the cribbing is... keep it 90 deg to the smoke chamber.... cut out the smoke chamber to fit the tank.... cut out the tank for the proper smoker/firebox opening... You can have the tank front/back about anywhere on the top of the yellow tank and have the loading door and damper control at the far end.... Place the stack on the right end between the upper and lower rack.... put the warming chamber on the end where the stack is and have the stack part of it.... Just a thought.... do not know exactly what your ideas are....

Have you looked at the "pit calculator" for dimensions ????  http://www.feldoncentral.com/bbqcalculator.html

That is a nice sized smoker.... I'm in for this build.... I love watching creativity in action...   Dave ....  

  ....

here is a thought on paper....

maybe that makes sense now....  

 

[bmoore]

Yup almost exactly but I was going to mount the chimney basically as high as possible on the side like u drew. I was thinking to put two dampers both on the ends to hopefully get a more even burn in the fire box. And just had a idea to make a hatch style door in the fire box rather than one side to make loading wood easier and won't have to worry about starting a forest fire by pulling the wood box out to fill it.

 

[daveomak]

Yup almost exactly but I was going to mount the chimney basically as high as possible on the side like u drew. Above the lowest grate works well.. keeps the heat in the smoker and keeps the smoke and heat traveling at  meat level.... I was thinking to put two dampers both on the ends to hopefully get a more even burn in the fire box. Install the draft, keeping the fire between it and the smoker.. that should be more than adequate....     And just had a idea to make a hatch style door in the fire box.. Great idea... rather than one side to make loading wood easier and won't have to worry about starting a forest fire by pulling the wood box out to fill it.

I don't know what you have searched, here is some interesting info....

http://www.smokingmeatforums.com/t/54542/building-an-italian-offset-smoker/20

 

[bmoore]

Got many hours of research on this site, and used the feldon calculator for the specs

 

[bmoore]

Got the firebox filled with water as we speak.. Will post pics as I make progress

 

[dragons breath]

Nice start.

What's the wall thickness of the tank?

This should be a good build to watch.

A large fire box like yours will allow you to cook longer without adding more fuel.

 

[bmoore]

The fire box is 1/4" wall thickness. I haven't cut into the smoker tank yet but I think it is probably 1/8".

 

[dragons breath]

1/4" for the fire box is fine and 1/8" for the smoker will give you years of happy smoking. And the size is the best quality of your smoker. You can smoke anything in that monster!

My firebox is offset from center and works just fine. I didn't anticipate a warming chamber on mine and in the end I didn't have room for it. I want to see how you attach the warming chamber to the round firebox. This is what custom smokers are all about. Creatively solving problems for your own benefit.

 

[bmoore]

Originally I was going to have the fb door on the end but after thinking about it it would be much better to make it a hatch style door. So not sure where to mount the warming chamber.
The best idea I have so far is to make the door on the fb 18" from the end on one side and 12" on the other. Then radius the warming chamber out to sit on that 18" section. It should leave me enough room to slide my wood box in and load wood. Hopefully that will be enough square inches that it is attached by to keep it decently warm.

 

[daveomak]

bmoore, evening.... think about.... Having the fire box end flush with the front of the smoking chamber so it extends behind the smoker... Have the trap door on the extended end..... have the warmer surround the exhaust stack...  The scan came out pretty bad....  Dave

 

[bmoore]

The basket needs to be as long as the fb correct? If that's the case then I would just pull the basket out halfway from the door on the end to fill the side under the warmer?

 

[daveomak]

bmoore... the basket only needs to be as long as the chunks of wood you use.... maybe a little longer....  or big enough to hold 25#'s of briquettes.... or what ever your fuel is.....  the rest of the firebox is just a duct for transporting the heat and smoke to the smoker.... the hatch only has to be big enough to throw in the odd chunk of smoke wood or a stick or split.....  Make sure the hatch can be air tight so your draft control is what is controlling the fire and heat output..... air leaks cause nightmares and headaches you can't imagine.....  Dave

 

[daveomak]

bmoore.... The basket can be as big as you need....  it can be full length of the smoker if you want.... the hatch should be air tight for temp control.... with that size smoker, you might want a basket that holds 50#'s of charcoal.... I'm not sure if you are using charcoal or splits.... anyway, you don't want to remove it during a smoke, (maybe),... you can add splits thru the hatch or smoke wood to the charcoal or whatever without having to open the firebox access door.... sounds like a cool unique project to me.... Dave

 

[bmoore]

Thanks Dave The smoking I have done up till now has been with 100% charcoal. I would like to use both maple wood and charcoal and supplement the flavour with a basket of chips. Basically planning on experimenting to see what works best. The idea of using maple the I have for free is very appealing
When I use the smoker calculator my fire box comes in at 95%, and there is a good chance I will be using this thing with air temps of 50deg f. I will draw what I have planned up on the tank. Would it make sense to just have a ash door on the end if I can get a decent size wood box through the hatch door?

 

[daveomak]

bmoore,  I would make the entire end removable for full access to the firebox.... make the access hatch, for adding fuel, what ever it needs to be...  Dave

 

[bmoore]

Dave, not sure what u mean by having the warmer suround the chimney? Were u thinking to run it up the outside of the warmer against it or right through the inside of the warmer?
And for what purpose would I want a door on the end of the fb if I can get the wood box out through the hatch? Just seams like a lot of work and not much to gain. Plus the possibility of air leaks. The only thing I can think of is so the hatch can be smaller and it will let less heat out when it is opened. If that is the case I could make the hatch a double door.
Almost have the hinges done for the doors. The plan is to cut the doors on the fb and smoke chamber Fri night.
How far should the fb be set into the smoke chamber? I know the height is set by the fb to smoke chamber sq in calculation. My fire box is 24"dia so I was thinking 10"?

 

[daveomak]

bmoore, evening... Getting ready to cut already ???  Sit back, relax.... draw everything out to scale... draw it all on the smoker and firebox also ... in white chalk....  make sure it does everything you want it to do....  it is easier to erase chalk than re weld and cut again...  measure everything twice.... On the ends of the smoker, draw in the position of the RF plate and the cooking racks... Check the door opening... etc...  Mark the exhaust stack.... Look at where a warming oven might go... When you get that AHA moment.... Dive in.....   Dave

 

[bmoore]

Does the fire pit calculator take into account that at the opposite end of the fire box air flow area will be reduced because of the drop of the reverse flow plate? I noticed that the fire pit calculator was not reverse flow specific.