My 100 gallon propane tank smoker build

Discussion in 'Reverse Flow' started by jmud, Jan 28, 2013.

  1. jmud

    jmud Meat Mopper

    Sweet, thanks for the help. I was also gonna ask how high to put cooking grate so that's great. If a 20" fire box will work I will just do that, and also a 20" warm box. I really don't want the box to get any where near above 200 degrees, so you said insulate between the two. What is a good suggestion to insulate it with?
     
  2. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    The warming box will scavenge heat from the firebox and cook chamber...  If it is too cool, throw a welding blanket over it for insulation..  If it's too warm, a couple air vents top and bottom of the sides, of the warming box, will cool it down....  It will be a trial and error, summer and winter, rain or sunshine, blowing or calm type of adjustment I think... 
     
  3. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    jmud..... another idea....   heat control of the warming box....  increase the heat in the firebox using the lower air intake... close the upper air intake a bit... that will heat up the firebox and warming box...
     
  4. jmud

    jmud Meat Mopper

    Picked up trailer frame tonight for $50. Tomorrow will take off valve on tank and flip upside down for a few days, maybe longer. Kinda cold right now to fill with water just yet, but will indeed. Hopefully will figure out how to upload photos too. Trip to junk yard too to get steel plating and grating. Hope they got. Also thinkin about scrapping the warming box idea and just using a single fire box. Getting excited
     
  5. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

     .......[​IMG]  .......
     
  6. jmud

    jmud Meat Mopper

    Got my steel plating today. 1/4 inch plate steel, also found a piece in the neighbors barn that my dad works for. That sheet roughly 4 by 4 feet, and bought the other 2 pieces a bit bigger than that one, 45 cents per pound, 171 bucks. Think I got a cooking grate in our old barn, the grate squares are roughly 1 inch by 3 inch. Too big? Plus, by my calculations the cooking grate will be 10 inches above bottom of tank. Should bottom of door be maybe an inch or so above that?
     
    Last edited: Feb 2, 2013
  7. I think that grate might work. Ribs, butts, brisket, or chicken won't fall through that. If you plan on doing something smaller it might be a problem. I would put the bottom of the door below the cooking grate and make the grate slide out. I don't think you would regret this.

    What really suprises me is the price of that steel. I got a quote last week for a 4x8 sheet of 1/4" for $155. I just calculated it and that is 47.5 cents per pound. That was for a new sheet from a supplier. He also quoted me a 4x8 sheet of 3/4x9# flat expanded for $46. I think I need to go get that before he changes his mind.
     
  8. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Is your firebox built yet ??  1 x 3 should be OK for the fire grate... It not, throw some big expanded metal on it...  

    Have you cut into the tank yet ??   A few dimensions should be checked before you do....    Dave
     
  9. jmud

    jmud Meat Mopper

    Haven't cut anything or built yet, but chomping at the bit to do so. Might be a few weeks before I can. What should be checked? Got this updated plan;
    29.7 by 42 tank (triple checked this)
    22" firebox
    28"-5" exhaust or 19"-6" or 42"-4", whatever I can get for pipe. Got something around here
    4-3" intake holes with slide damper
    4.8 inch fb to cc opening height
    Rf plate 6" above bottom
    Rf plate end point 8" shy from end of cc
    Cook grate 10" above bottom of tank
    Drains for bottom of tank and rf plate

    If you see any tweaking needed feel free to let me know. Love the guidance here
     
    Last edited: Feb 2, 2013
  10. jmud

    jmud Meat Mopper

    And here's an idea I had. I'm the kind of guy that likes to have something never seen before. How about a dual stack at one end? Like two 21" pipes?
     
  11. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    jmud.....   We have to do some refiguring....    You said it was a 100 gallon tank... 23,100 cu in.

                                                                        30 x 42 tank ................................29,000 cu in.

    Must be a 100 gal net...  allowing for 20% expansion space  29,000 x .8 =  23,200 cu in. or 100 net gal.

    A 25% larger cook chamber is a big jump....   

    It is time to think......    Dave

    New numbers almost done.... I am drawing up a plan....  be done tomorrow...   Dave

    http://feldoncentral.com/bbqcalcula...9&fi=3.25,3,0,30.00,3.08&fc=10.10,14.27,80.00
     
    Last edited: Feb 2, 2013
  12. jmud

    jmud Meat Mopper

    You must be absolutely right. Makes total sense with expansion. Refigure we will. Must look like a moron right now ha.
     
  13. jmud

    jmud Meat Mopper

    You must be absolutely right. Makes total sense with expansion. Refigure we will. Must look like a moron right now ha. My figuring was actually with my dimensions of 30 by 42, so 22" box says it works when I plug it into the calculator
     
    Last edited: Feb 2, 2013
  14. jmud

    jmud Meat Mopper

    It was "used" steel but not used for anything. Practically new
     
  15. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    can you post a picture of the tank.....  Dave
     
  16. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Morning..... I ran the new numbers.... they are below....  I drew up a reasonable facsimile of the smoker....   The design can be changed no problem.... certain values can also be change a little...   Insetting the firebox into the smoker is one idea... additional baffles in the firebox will help with efficiency in saving wood....  Inserting the stack through the top of the CC to allow for a warming box will work.... 

    I suggest drawing out all the components on the tank in chalk so you can check for clearances... ease of use... ergonomics... and what ever else comes to mind...  You could put a drain in the firebox so when the smoker is washed out (?) it will drain...  Check out other builds and see what those folks have done for ideas.... Once you start, I guess you could say you are in for the duration...  unless you like to tear apart and rebuild stuff....  

    There are some great builds on the forum... Any questions about this stuff ???     Dave


     
  17. jmud

    jmud Meat Mopper



    heres the $50 dollar trailer.  Plan to cut off back angle.  Thinking thats where the fire box will go.  Tank will go above axle.  Where the fire box and cc meet will be right in line of rear leaf spring shackles (if this makes any sense).  A box will be built between the cc and where the trailer toung meet for charcoal, wood.  I have the valve open and draining any propane out.  Really dont wanna fill it with water yet (its a warm 20 degrees out) so will do this next weekend.  A friend of mine has a plasma cutter.  Will have him cut all plating and door open on tank.  Will leave 4 corners entact so i can weld hinges on it first.  Learned that here.  What ya'all think?
     
  18. jmud

    jmud Meat Mopper

    And Im still thinking bout a dual stack, I just think it would look really origional. Saw a cab over semi this mourning with duals with a slight bullhorn tip on them, really got me thinking. Would I just split the total length in half for the two?
     
  19. jmud

    jmud Meat Mopper

    So......... I have all of next years firewood cut now, 12 cord. This weekend I got plans but the weekend after I'm gonna tackle the project. The plans look great thanks Dave. I'm going to do the dual stack idea, making length of each stack half of what total length is calling for. I know I asked, but no one really answered so I assume no news is good news
     
  20. Jmud,  Looks like you are getting ready to get this thing started for real.  I noticed in post #37 that you are going to cut off the back angle on the trailer.  This can be done but you will need to tie the smoker firebox into the trailer.  With that angle cut the springs will tend to pull the backend of the trailer in and your wheels will not be running true.  I think you can cut it but you will need to make that solid in some way across the back again from each side of the smoker to maintain the integrity of the whole unit.  Hope this makes sense.  Joe
     

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