Building first small 11g Reverse Flow need some help

Discussion in 'Reverse Flow' started by tommyp, Jul 21, 2014.

  1. tommyp

    tommyp Newbie

    I have been smoking on an ECB with mods for years and want a small smoker that I can put a couple racks off ribs on. I don't really cook for a lot of people so a big pit would be wasted right now. I want a reverse flow with offset box so it is easier to get at the fire and easier to get at the food. I am in northern VT so I would like something I could smoke later into the fall if possible.

    Parts so far.

    I ordered a 11 gallon air tank from Harbor freight that I am going to use as the CC.  It is 13" or so by 23".  I have some 2.25" exhaust tube kicking around that I am going to use as a stack.

    Main problems in planning so far.

    The one issue I have is building the firebox.  I have a 220 mig and a DC tig. but my cutting abilities are pretty much just a 4.5" grinder. I don't really want to make large cuts in 3/16" flat steel

    Was thinking of making a angle iron frame for the firebox and then lining with firebrick splits and using sheet for the outside maybe.

    I have access to a large box brake and a plasma but the plasma is my neighbors and It was having issues cutting some 1/4" plate that I needed cut so I had to go back to the grinder.

    What are people using to cut the large steel plates for the firebox? Plasma?

    I guess I could get 6" wide or so flat and weld it together instead of going at 12" plate with a grinder.  Worse comes to worse I can use cutting disks but I imagine it will be less than enjoyable.

    Any  firebox build ideas would be appreciated.
  2. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    If you use a calculator for the dimensions, at least double the numbers for exhaust, CC/FB opening and area under the RF plate.... In smokers that small, friction loss from surface area/volume is very high and needs to be adjusted.....
    ben bot likes this.
  3. lendecatural

    lendecatural Smoking Fanatic

    You really need to take the Plasma torch apart and take the consumables to the nearest welding supply store and buy a couple of tips and electrodes. For a lot less than you would spend on cutting discs, you can get that torch up and running great and make your neighbor very happy and save yourself a lot of time in the process.... If it is a brand name and you can get the part numbers, the best deals are on eBay and will be delivered in a couple of days but if you have a supply house nearby, $20 will get you three sets in most cases.
  4. tommyp

    tommyp Newbie

    Ok will do I was going on 1.5X but can double.
  5. tommyp

    tommyp Newbie

    Yeah I hear you. It is an off brand I think a version of the cut 50. He has it running on 110 and it really has trouble on 1/8" as it is. So it needs to be converted to 220 and have its consumables checked.  I am not sure how he is setup for 220 in his shop he may have to run outlets etc. So it becomes more of an issue.   I might have to rent a plasma for a week or so.
  6. lendecatural

    lendecatural Smoking Fanatic

    My Miller Spectrum 375 is 110/220 and switchable on the back of the box. Just unscrew the barrel on the torch end, remove the two pieces and you will be able to see what you need to do, they will be pitted and or burned, shouldn't be a reason to take it to the shop.....
  7. I just threw together a quick cooker from scrap with no shop set up yet ( just moved) I took a sheet of 1/4" plate to my local steel supplier, walked in and asked the guy operating the shear if he drank beer......his reply was " well, yeah, why", ....I asked what kind,.."bud light"......I ask, what car out there is yours... He says "that red ford ranger" I says, while I'm at the store buying you a case of beer, sheer this plate where I marked it and I'll set the beer in the back of your truck when I get back.

    That's how you cut large plates of steel.
  8. tommyp

    tommyp Newbie

    hhahahah The local place that I get steel at just has a large bandsaw and charge an arm and a leg for cuts.   I talked to my neighbor who is a fan of my bbq and I explained what I was making.  He is going to get the plasma wired for 220 and straightened out. 

    So what is the consensus on lining the firebox with firebrick? I may just do the top of the firebox. Since this smoker is going to be pretty small I don't really want to add the bulk of the firebrick. But will if it will help out in cold weather smokes.  I may end up putting propane in it for the fall/winter if I want to do some smoking. It just would be nice to extend the season.
    Last edited: Jul 21, 2014
  9. I'd skip the firebrick, honestly.

    If you wanted to insulate the firebox, check out the builds where they use rock wool. I'm in Florida, and a double plate with air gap works just fine for me. And plenty of people are happy with just single layer plate.
  10. tommyp

    tommyp Newbie

    Ok, I'll probably just make the fire box a little bigger leaving room to double wall it if necessary.
  11. tommyp

    tommyp Newbie

    So the tank showed up today

    cut the door

    relocated the handle

    added a lip around the door

    Made up some hinges

    had this spare grill kicking around so I cut it to fit. I will probably replace it with something later to take better advantage of the limited space but it will do for now I guess.

    Cut the exhaust hole for the 2.25" exhaust tubing I had kicking around

    How should I cut the inside? 45 degree angle?  Is the exhaust too far down? I was basically winging it.
    Last edited: Jul 24, 2014
  12. tommyp

    tommyp Newbie

    Moving on. Picked up some steel and moved the build temporarily to my dads shop.  Got a little warping on the reverse flow plate but it isn't terrible I will pull it back.  Was running too long of beads.

    Started building the firebox. Drew something up but kinda winging it as I go. This top frame is 1" x1/8" wall square tube.

    chopping up the plate for the inside of the fire box. 3/16" thick on the inside.

    mocked up a little.

    Need to figure out how I am going to vent this thing. I have lots of 1.5" tube so was probably going to run pieces of them through the walls. Need to see if the plasma is up and running.
  13. take a ride down to windor to the harpoon brewery this weekend their holding a smoke comp, it'll give you a lot of idea's. 


    This is what we use, works great


    Roxul Acoustical Fire Batts, Mineral Wool, 2-inch (6PK)

    Point to an image below to see a larger version.
    [​IMG]    [​IMG]

    • Price and Order
    • Item Description

    Price: $36.00  
    Currently ships within: 1 business day. 
    Made in Canada. 


    Want something special? No problem!

    Custom sourced sizes? Bulk quantities? Mixed cases? Special cuts? You name it! Just give us a call toll-free at 1-866-787-7881.

  15. tommyp

    tommyp Newbie

    Cool! I don't think i will make it to the Brewery been on the road all day today and have to drive some more tonight. Too bad it would be good to see a comp.

    The rockwool is cool but i am going to use some of the kaowool kiln blanket stuff. I ordered it Thursday from a place in NY so hopefully it will show up early next week. I am only running an inch of insulation room. So i wasnt to keen on cutting up the rockwool or compressing it that much. Or have a crapton of it left over.

    I think i can do a test burn without the insulation so I dont think i have to wait for it if it takes a while
  16. tommyp

    tommyp Newbie

    Attached the fire box to the CC

    A close up of the firebox opening. I closed it up with a 1" piece of flat after the pic.

    Firebox with sloped walls that hold up the grate as well.

    Door finished. Legs attached and the bottom supports bent up.

    Not finished but ready to smoke! Harbor freight 10" wheels. I use them on everything. takes 5/8" rod as an axle.

    Two racks fit snuggly. 3 would fit with a vertical rib rack. 

    Didn't plan this and it is a little loose but you could fit two trays down there.

    Lowes thermometer

    In action

    Que view

    Super stable with a mix of lump and briquette

    Still need to put a handle on and insulate.
    Last edited: Jul 28, 2014
  17. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Darn nice looking smoker..... Thumbs Up
  18. Good Job     Looks good

    Gary S
  19. tommyp

    tommyp Newbie

    Thanks for the ideas and help guys it was a lot of fun to build.

    So much nicer to cook on than my old vertical drum style cheapy.  Got a bit more to finish on it but I do love the way it smokes.
  20. gent

    gent Fire Starter

    Looking Great,  I have a nice pit,  but I want to build something small like that.  For those smaller meals.  Pick up some firerope and seal around the door etc and you'r set.

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