Small backyard reverse flow build

Discussion in 'Reverse Flow' started by txsean, Feb 4, 2014.

  1. txsean

    txsean Smoke Blower

    Hey guys. So I've just recently started a backyard reverse flow smoker build. I'll just say that I've outgrown many aspects of my store-bought cooker, and... well, I just always have to be building/working on something, so why not a grill as my next project ;) Only  recently have I started visiting this section of the forum too, and it seems like a cool spot to hang out for a bit, and share my build, so here it goes.

    This is my first grill build (of what I'm sure will be at least a few more to come) and I wont even claim to be an expert or experienced metal worker, but its been fun so far. The plan is a 24" diameter cooking chamber with a planned length of 48". Not 100% set in stone as I've yet to be able to get ahold of any pipe. The past few days I've been toying around with the idea of trying to find a tank, probably 120 gallon if possible. 150 might be pushing what I'm looking for size wise but will roll with it for the right price. We will see where that goes here in the next few weeks. 

    As of right now, I am just about done with my firebox. The box is a 22" square box with 4" x 7" air inlets on each side. I've run my numbers through the calculator and my air inlets are almost twice what I need, but I wanted the ability to close one side off if necessary (due to weather/wind) My fire grate is about 4.5 inches off of the bottom. I believe I will still have plenty of room for a fire and flame, but will have plenty of room for ash and air under the fire as well. I will put some expanded metal over the air intakes and I still need one more piece of strapping on the top edge of the door opening. Still need to work on the fire grate as well. 

    I had not originally planned any type of deflector plate or anything on the top of the firebox, but now I am starting wonder if I should while its going together. I've seen different designs, and I'm not sure if I want to suspend a plate from the top, or maybe add a layer of 1" insulation to the top. I know insulation isn't really needed here in Texas and I do not want to do the whole box, this would just be to help preserve the top of the box, and possibly help with heat and fuel efficiency... in theory anyway. Maybe I've mis-understood and this isn't even necessary in my case. So, thoughts on that would be appreciated. If I were to do so however, the original plan was to mate the reverse flow plate up flush with the top of the firebox. If I suspend a plate, that I would have to adjust for that and possibly mount my firebox a little higher than planned. Or the other thought I had was to just add 1" insulation to the top and weld in another plate... ??

    Anyway, those are some random thoughts. All build threads are worthless with out pics, so heres the fun part :p Thanks for looking!

  2. txsean

    txsean Smoke Blower

    Maybe what I'll do if anything is take a1/4" plate, 20" square and suspend it about a half inch from the top. That will give the top room to breath but help block direct heat from hitting the top. Not sure if this would do too much to help slow down heat loss but I'm not even sure that will be a huge concern. I'm sure she will still cook great and will be a lot better than what I'm working with now. Just want to make sure I get every thing worked out now instead of wishing I had done something after the fact.
  3. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Here is a method for hanging the "deflector" plate........ "spacer" thickness 1/4 - 1/2".... the air gap will reduce heat loss and overheating of the first section of the RF plate if it is inserted into the CC a foot or so..... on pic to enlarge........
    Last edited: Feb 4, 2014
  4. Just go ahead and dive in all the way and build a 24" box around the outside of that one, attach the reverse flow plate to the outer top plate and the deflector to the bottom.

    Yeah I know, a lot more work. But 24" box will fit and look better on a 24 inch wide tank. Finding 24" pipe in 1/4" wall is going to be hard. You will probably have better luck with finding a 120 or 125 propane tank, and they will be just a hair under 24".

    I'm going to go ahead and do that myself this weekend on my current build. The top and bottom are already double plated with 1/4" plate, I'll probably use 1/8" and line the inside with a small air gap. I was thinking about a heat shield for the tires and then just decided to do it from inside the firebox and see how it works.
  5. txsean

    txsean Smoke Blower

    Doesn't get any more clear than that. Thanks Dave. Thats about what I was thinking about but hadn't thought about the bolts. I'll keep this in mind as an option. How far into the cooking chamber under the reverse flow plate do you think this should go?
    RW, I agree too, in hindsight I think the 24" box would have looked better, and I probably should have gone that route to begin with... but I'm not sure at this stage I want to change that. I'm not ruling it out, and in the end, I know its just time and I want this to be the way I want it. I'll just have to entertain ideas and figure out what I want to do. I guess if I hadn't already welded on the door hinges and welded and smoothed out the air intake dampers, that I would be more inclined. I was surprised insulation isn't very expensive. If not on this build then my next build I think will definitely be an insulated firebox. 

    I wasn't terribly crazy about tank builds at first but they are really growing on me the more I look into them. You're right about pipe being hard to find though! I did find a guy that says he usually has some 24" pipe, just sold out at the moment, but he only gets 3/8" thick pipe, and I'm not really sure I want or need all of that weight lol
  6. txsean

    txsean Smoke Blower

    Air intake. I guess all I would really need to do would be to cut the door out, and re-frame it on the outer layer... hhmm....... 

  7. Yep, it would be easy to do.

    I've found that people either like the tank look or they don't.

    For me , it an easy decision. On a pipe build, you have to cap the end. When I just installed a flat plate, I found that the end plate got quite a bit hotter than the rest of the cooking chamber, the air was hitting that flat plate as it came out from under the reverse flow plate and i was loosing heat out of that end of the cooker. With the rounded end of a tank, it was not as bad. Easier to just start with a tank than try to fabricate a rounded end cap, right? And a lot cheaper to pay scrap price for a tank than what new steel cost.

    Even if I was to fabricate another one out of pipe, I would cut the end in a radius so that the air would flow better.
  8. buda q

    buda q Smoke Blower

    Sean, that's looking real good so far.
  9. crazyq

    crazyq Meat Mopper

    If i had the tank option when i started my build i woulda jumped on it but it wasnt available and i got my pipe for dang near nothing so i couldnt pass it up. Now i cant find a 24" tank cap so im gonna have to either flat plate it and deal with it or come up with some kind of "ramp" on the inside to assist with making it easier for the heat to "roll" around the end of the reverse plate.
  10. crazyq

    crazyq Meat Mopper

    Basically, try and make it more "areodynamic" so to speak.
  11. txsean

    txsean Smoke Blower

    CrazyQ, I look forward to seeing what you end up doing with yours. You have a nice build going... I saw a post you made somewhere else about wanting to find a cap and I thought that was a great idea but I wasn't able to find anything like that either. The tank idea has really grown on me and I think I am really wanting to go that route. I will have to call around to see what I can find, but before too long will jump on whatever I can get my hands on. I will have to call around and see what I can find.

    That being said, regardless I am planning on extending this to a 60"-ish cooking chamber from the originally planned 48". If I'm going to upgrade, might as well upgrade right?
  12. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Check out RW's threads.... he built one with a "tunnel" on the end to move the heat.... Said it worked better than an end cap.......
  13. crazyq

    crazyq Meat Mopper

    Thanks, i'll be sure and check it out.
  14. crazyq

    crazyq Meat Mopper

    Yeah i went with a 60" CC as well on mine. Had a 48" before and always needed more room it seemed like.
  15. txsean

    txsean Smoke Blower

    deleted, re-working thoughts...
    Last edited: Feb 14, 2014
  16. txsean

    txsean Smoke Blower

    Finally finally finally... an update! After weeks of calling places just days after they sold out, I was finally able to find some pipe. The pipe is 3/8" wall and heavy! A little too heavy for what I wanted (a backyard patio cooker) but I can work with it. I'll just have to rent a tractor or something every time I want to move it lol. 

    Over the past few weeks I have been trying to knock out any small things that I could with out the pipe itself. I built a fire grate/basket and framed out the main stand. I also continued to run numbers to make sure I had everything the way want it... or at least how I think I want it. This is my first build so we will see how she works and I'll just make adjustments for the next one ;) 

    Still need to pick up some expanded metal to finish up the fire basket (and for the cooking grates), then I will add either some rebar or rod across the bottom as reinforcement. I also added and anti-tilt rail for the bottom, but didn't get a picture of that. 

    The main frame, also waiting for expanded metal, and wheels ...

    And finally, on to the goods. Was hoping for new pipe... but beggers can't be choosers. So, next time I'm extremely bored I will have some work to do knocking off the paint. I might wheel it out to the drive way once I get some wheels and burn it out. If I don't wire-wheel it first. Paint seemed to come off quick when I was prepping for welds so it might not be too bad. The inside it rusty and will take some work as well. It will get there though.

    So this is what I'm working with...

    And this is where she stands after a good days work ;)

    So.... minor detail, but she's upside down! lol Will be an interesting task of rolling it over, but I wasn't excited about welding upside down, nor am I any good at it. Plus I got rid of my engine hoist years ago and don't really have a good way of moving this pipe around. I think its going to be a good size though, I'm excited. Its 24" diameter, as planned, but 54" in length. Next up (besides getting it right-side up) will be to cut out the door and start working on the RF plate. 
  17. crazyq

    crazyq Meat Mopper

    Looking good. You can start rockn and rolln with it now
  18. txsean

    txsean Smoke Blower

    Thanks. Definitely enough to keep me busy for a few days.

  19. lendecatural

    lendecatural Smoking Fanatic

    How did you do the lift? Rotate the picture??[​IMG]
  20. txsean

    txsean Smoke Blower

    lol I wish it had been that easy. Between the pipe and firebox I calculate I'm in the mid 600 pound range already :icon_eek: I'm going to need a reinforced patio

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