80 gallon build

Discussion in 'Smoker Builds' started by newsite smokers, Oct 26, 2011.

  1. So I have an 80 gal air compressor tank that I want to build into a smoker. I was looking on the custom build thread and saw the pics of peoples custom builds.I noticed that some had the smoke stack opposite of fire box like the one I have at home and others had it on the same end. I thought it needed to be opposite to pull heat and smoke across the meat. So #1 Whats the difference? #2 Does the fire box metal need to be 3/16 or 1/4 inch steel? #3 Diameter of exhaust stack ? I'm sure I will have many more but these will give me some starting points and get some thoughts started. Thanks in advance for any help!
  2. smokinal

    smokinal Smoking Guru Staff Member Moderator OTBS Member ★ Lifetime Premier ★

    [​IMG]    Glad to have you with us!

    There are a lot of builders on here who can help you with your project.
  3. raptor700

    raptor700 Master of the Pit OTBS Member

  4. sqwib

    sqwib Smoking Guru OTBS Member

  5. jckdanls 07

    jckdanls 07 Master of the Pit Group Lead OTBS Member

    The reason you see the smoke stack on the same side as the fire box is that it's a "Reverse Flow" smoker. Look threw the reverse flow builds and you'll find out why it's called that. As for your firebox, I would say at least 1/4" If not thicker. Good luck with your build and welcome to the forums.
  6. Welcome to SMF. Will be lookin forward to seeing your build.

  7. how do i figure what size to cut door? I mean should it start half way down side and go to top dead center or just pass center of top?
  8. I cut my door just past to dead center to the back so there would not be a crack at the top for the heat to escape.  And for how far down will depend on the style of smoker u decide to build .  I built a reverse flow and cut my door about an inch above the baffle plate so i could fill with water to help keep the meat moist.   As for the fire box steel the thicker the better for heat distribution, that being said steel is expensive and I used 3/16 diamond plate 1/4 in at the diamonds.  I have used the smoker for one summer almost every weekend, every weekend the wife would let me and I have no signs of warping yet.
  9. wheres the best place to get hinges and Thermometers?
  10. raptor700

    raptor700 Master of the Pit OTBS Member

        KCK has some great hinges and thermos.

    Last edited: Nov 3, 2011
  11. smokey mo

    smokey mo Smoking Fanatic OTBS Member

    The best advice I can give you is do A LOT OF RESEARCH BEFORE YOU CUT ANYTHING!

    Please take your time.  If you are a good fab guy you can lay it out quickly.  If you are not a fab guy, find the tools they are here.  Go through and see what works and what doesn't.  Is it going to be desktop model, trailered model, have a warmer, no warmer, reverse flow side fire box, rear firebox. no firebox, verticle.  There are so many things you can do. Take your time.  We are all more than glad to give you our never to be humble opinions.  We love this stuff and can't wait to share. But the choices you make now will affect that build good or bad.

    My suggestion is to make a reverse flow. Just me. I like them.  and not too much more difficult than a standard side box job. You just have to do a little more math and 'thunking' about things.

    Good luck and hope to see more from you soon.

    Try searching for the build calculator tool. I cant seem to find where I saved mine to but it is a must.
  12. mballi3011

    mballi3011 Smoking Guru OTBS Member SMF Premier Member


    First off welcome to SMF. You'll like this place for there are alot of folks here that would just love to help you with just about anything to do with smoking meat. You will find alot of good recipes and techniques here also. so with all that said:

    Welcome to your new Addiction.
  13. roller

    roller Smoking Guru SMF Premier Member

    Thats a cool site....
  14. OK a few questions. on a reverse flow the plate in bottom----> how high off bottom does it need to be? how thick ? and Does it need to have a drop or something to funnel the drippings off? thisa is on a 80 gal air compressor tank . I was going to use 1/4 steel for the fire box prob a 2' x2' or 18" x 18"
  15. scarbelly

    scarbelly Smoking Guru OTBS Member

    Since your post was in Roll Call and might not get the replies you need, I moved it over to Smoker Builds. Good luck with your project  
  16. smokey mo

    smokey mo Smoking Fanatic OTBS Member

    I built mine out of 1/4" steel.  It is a 500g propane tank reverse flow with a 24"X24"X41" firebox. 1/4 will work just make sure you add cross supports ( angle Iron) on the doors and walls to support it when it gets hot. The height depends on the size of the opening. Yes have a slight drop from the fire box to the drain in your reverse flow plate. and from sides to the middle of the plate. Try these to do figures.  You are going to have to do some math. Ok. A lot of math.  Get a chalk line to help with layout for the plate inside and an extra set of hands. The numbers you are looking for are volume of air flow, ie. air flow from firebox to smoke chamber and smoke chamber to exhaust. They need to be basically the same.  That includes the volume in the chimney created by the horizontal plate going end to end and also the turn from the far end to the smoke chamber as that is just part of the chimney. 

    You want your fire box to be pretty close to 1/3 the volume of the cook chamber.  When figuring that number break the tank into parts.  both ends of the domes on mine worked out to be a sphere and then the main portion was a cylinder So I just worked the math for both parts then converted to Cubic inches.  about 96000 cubic inches, then played with the firebox numbers to match the width of the tank and kept it close 1/3 of that.  Vents are huge.  Make them so they are easy to shut down.  If you don't you will get air leaks that will haunt you.  You can always shut them down but opening more is hard if you don't have anymore to open. [​IMG]   Don't forget the to plan for ash removal.  It is imperative on long cooks. 

    Good luck. You can PM me if you have more questions or need clarification.  I am not the best by any means but I am willing to tell you where I wish I could have done things differently.

    Read read read, plan, draw and annoy the family with pictures until they tell you to start building.  Then read some more.  Take your time it is worht the work.

    http://webpages.charter.net/tomchism/Dodis Calculator/

    http://webpages.charter.net/tomchism/BBQ CALC Forms/BBQ Smoker Calculators.htm

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