My smoker

Discussion in 'Side Fire Box' started by onebdgti, Jul 8, 2013.

  1. This is my homemade smoker that I made from a lot of scrap metal from work. All I paid for was the expansion metal and angle Iron.  for a grand total of $52.  Not bad at all if you ask me.  Its made from 3/16 steel and 2x2 1/8 angle iron .  Gotta finish up the dampener and basket so I can fire it up this weekend.

    Yes I know the hotbox is a little large but it was already made and all I had to do was make a door for it.  Let me know what you thin of it.
  2. link

    link Smoking Fanatic SMF Premier Member

    That looks pretty damn good and for $52.00 you cannot beat the price. Can't wait to see what comes out of it and how it cooks.

    Nice job!
  3. I'd add a grate in the firebox as well just so you could grill in there to make it a dual purpose rig!
  4. That sounds like a good idea on the grate. I have some black bar grading laying around lol. Wonder how big I should make my dampener. I am new to this stuff.
  5. Ok I have used the smoker about 5 times already and it is hungry for fuel. When I built this rig I knew nothing about building a smoker. After I finished it and found this site I read about a pic calculator. So after some number crunching I find out that the hot box is way to big. So I will be taking a grand total of 10" off of the length of the hot box. Hopefully this will help with my fuel consumption problem.
  6. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Mike, evening......  Hey, before you go cutting up the FB, check the stack size and opening between the FB and CC.....   Also please post a picture of the FB air intakes and their location.....     Over sized fireboxe shouldn't burn extra wood, poor air flow and an overheating firebox burn extra wood.....   give us a chance to look stuff over......     Post all the dimensions and I will look at what can be done....   

  7. Ok pics I can do.

    The Stack is 3" ID and is 26 1/4" long.  24" sticking out and 2 1/2 in the smoker.

    The opening on the FB to CC is 4"x8"

    The dampner is not a full circle but measures rite at 4"  I think this is one of my big problems not enough air flow.  I was cutting it out with my torch and I ran out of oxygen.  I am thinking of making it a 4" square instead of the circle. 

    The smoker measures 16"x22"x30"   The hot bod measures 16"x16"x24"

    Any help would be awesome.  For this is my very first build and it is made from a bunch of scrap metal that they were gonna throw away at work.  The hot box was already made just not the door.

  8. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Mike, morning......  Hey, it looks like it should work given the numbers......  

    stack = 176 ...            recommended

    FB in = 11 sq in  ....   recommended

    FB/CC = 28 sq in ..... recommended ....

    stack  7 x 26 = 183 cu in actual

    I do think there is room for improvement.....  

    First, look at the bottom picture...  the FireBox with the second air inlet.... the black one.....  That is an important feature in a SFB smoker...  When the FB gets hot, it sweeps the hot air into the cook chamber....   the lower air inlet can be closed down a bit to conserve fuel while the Cook Chamber stays hot...   It's a balancing act that will take some getting used to.....

    Second, looking at the picture below.....  I assume that is of the interior of the CC...  and I see what appears to be a Reverse Flow plate below the mesh screen.....  The RF plate appears to deflect downward, cutting off the air/heat flow from the FB to the CC.....  If that's so, not a good deal for 2 reasons.....  It's cutting off the air flow and your smoker is not a Reverse Flow.....   You need tuning plates instead of the RF plate...

    Tuning plates are spaced such that heat entering the CC can rise toward the food at a rate that will be equal across the cooking grate, or something similar....   When installing a RF plate or Tuning Plates, it is very important to keep them ABOVE the FB to CC opening so as to not obstruct the heat/smoke/air flow to the CC..... See the middle drawing for a somewhat reasonable drawing of what I'm trying to explain... The gap, between the plates, allows the for gradual increase in heat, to rise to the food.... 

    I recommend pulling out the RF plate and cutting it into 4" wide strips, or something like that... weld or bolt a couple strips, inside the FB, ABOVE the FB/CC opening, to support the Tuning Plates....   

    Support the food grate 3-4" above the Tuning Plates, or something like that....

    Add a second air inlet to the FireBox like in the picture directly across from the FB/CC opening....  In the bottom pic, you can see the lower air inlet mostly closed down and the upper air inlet open and moving heat to the CC....   that keeps the FB from overheating and wasting fuel...

    Then if you need additional performance enhancement, the stack does not need to be that tall....   the vertical CC is acting as a stack and the friction loss, due to the length of the stack,could be affecting it's ability to draft...

    With those minor changes, I do believe you will have one fine smoker......

    Hope this all makes sense....  If not, PM me and I will try to improve on my communication skills........  Dave

            ......CLICK ON THE PICS TO ENLARGE.....

    Last edited: Aug 12, 2013
  9. Wow this is very helpful.

    I thought that I was just adding a baffle and not making it a reverse flow.  Hmmm sounds like that will be the first thing that I will do to it 

  10. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Mike, Can you flatten it out and drill holes in it then set it on some rails to get it above the FB/CC opening....???    No holes for the first 6" would be my guess...  Then 1/2" holes on 3" centers......  as the FB end of the CC will be hotter than the rest of the smoker......   There are several options.... lets check them all before we jump in.....    Dave
  11. Dave, It is a flat piece of sheet metal.  I have it resting on to brick that are laying down on the far left side. 

    So basically drill some 1/2 holes 6" in on 3" centers correct?  So about how far should I continue the holes?

  12. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Mike, evening....

    I think the bricks are blocking the heat/smoke flow through the smoker...

    I'd start about 6" from the firebox drilling the holes then put them on 3" centers to start with.....   Something like this...... I would also end the diffuser plate 4" or so from the exhaust end of the smoker.....    

    Have it butted up tight to the firebox end and tight to the sides...(air tight that is)  that will insure good heat/smoke flow throughout the smoker....  If you find you need more heat in an area of the smoker, drill more holes...   sometimes a warmer zone and cooler zone is desirable also.....  this whole thing is what you get used to when cooking.... but it is always good to start with a plan and you can change it up as needed.....

    The pic below is just an example..... spacing of the holes can be changed....  use a step drill if the steel isn't too thick..    don't block any area under the plate so you have good air flow...   If you want a little moisture added when smoking, a tuna can with water will add moisture...  set it on the diffuser plate neat the firebox...   


    After doing some number crunching, I would drill the holes to 3/4"... and drill 18 of them ....  adjust the spacing as seems appropriate... on pic to enlarge .....

  13. Gonna build this plate tomorrow nite after work. Only problem I have is height. I will not have about 2-3 inches between the tuning plate and expansion metal.

    The tuning plate already has a place to bolt it about the opening of the FB/CC. Mite have to space the expansion metal up a little but thay will take the cooking surface about the door on the CC. Not sure if that will affect anything or not.

  14. Wow, I removed the RF plate that I thought I was adding a baffle and what a difference it made.  Next mod will be a tuning plate.  So far one mod at a time to see what affects the smoker the best.  The test meat was chicken to see how the smoker would do.  So far awesome!!!!!!!!!!!!!

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