# 250 Gallon Build from a noob. What do I do for an exhaust?



## Darth Stig (Dec 13, 2021)

Hi everyone,

I'm building a bottom dollar offset smoker and need help with ideas and size I should get for my exhaust. I have a 250 gallon propane tank as my CC. 

For my FB, I'm doing something I think I haven't seen anyone else do and I'm hoping it'll work. I'm taking 2 55 gallon drum barrels and I've shrunk the over all circuference of one by about an inch to stuff it into the other. From there, I'm packing the inside with kaolin wool, the same stuff kilns are made of so the FB is incredibly insulated, hopefully making my life and fire alot more efficient (at least that's the goal). 

Now the problem I'm having is the exhaust. I figure bigger is better because I can add all sorts of baffles and stops to restrict airflow. From what Franklin and others say, I need a super tall exhaust at least 8" in diameter and 6-8' in length. If that's true, I don't know where to get a non-galvanized/stainless piece of steel especially for cheap or free. That being said, I was thinking of using multiple pipes anywhere from 1-2" a piece and having anywhere from 5-10 of those pipes (I'd have to do the math to make sure my area of cylinder volume is close). Has anyone done this, and should I just bite the bullet and buy stock? A piece of pipe like I need is going to cost a small fortune in this economy. For reference, I live just north of Atlanta. Any suggestions would be amazing. Craigslist and FB marketplace are terrible to find something like this.


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## unclebubbas bbq (Dec 13, 2021)

Fabricate a square exhaust using cold rolled steel


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## Hardluckbbq (Jan 21, 2022)

Check the steel supply places for reject pipe. All of them have it around here and it's not crazy expensive. a lot of people do 6" stacks on 250 gallons.


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## Brokenhandle (Jan 21, 2022)

Maybe 

 daveomak
  will chime in and tell you exactly what you need. I know he helps many others on this topic.  I'm not sure where to tell you to look...have you tried search button or look through smoker builds?
Make sure to take pics...we wanna see also!

Ryan


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## ConcreteDonkey32 (Feb 2, 2022)

Darth Stig said:


> Hi everyone,
> 
> I'm building a bottom dollar offset smoker and need help with ideas and size I should get for my exhaust. I have a 250 gallon propane tank as my CC.
> 
> ...


O


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## daveomak (Feb 2, 2022)

(4) Standard Reverse Flow Smoker Calculator... by DaveOmak and others... Ready to use.. rev5.. 6/19/15. | Smoking Meat Forums - The Best Smoking Meat Forum On Earth! 

Follow the directions in this tutorial...  You will have a great smoker...


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