Ok. Here we go again. Rf #2.

Discussion in 'Reverse Flow' started by isaac, Apr 13, 2016.

  1. Just want Dave to inspect my math and confirm all is good befor I start my build. I attached a pic of my calculations for ease of not typing on the phone.
    Thanks all.
  2. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Your numbers look good......

    I would go with a Segment height of 4.5" with a Chord AB of 16.5" ish RF plate width.....  Just to insure good air flow.....  but it's up to you....  

    For the exhaust stack,   276 cu. in.       3" exhaust tubing 36" above the CC...  + whatever you stick into the CC or hook up to the plenum...

    As always, these numbers aren't hard and fast but represent smokers that work...   Insuring good air flow is the objective for a smoker that works very well......  
  3. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Exhaust tubing being.....  Car or truck exhaust pipe...    check with local muffler shops or truck centers.....
  4. When my plates came off the burning table the cord length was 16.5" and my segment height was 4.4", i am going to use a side mounted plenum with a 4" id pipe. 

    Im eating a quick lunch then im off to shear my 3/16" plate for rolling. Working in a welding shop helps. once i have all the pieces my son and i are going to fit and weld it up at home.  i will post some pics as i get them. Thanks again oh great Guru.
  5. I'm in   [​IMG]  [​IMG]

    isaac likes this.
  7. Just got it cut and sitting there for a look. Next I'm cutting FB opening. And rf plate.
  8. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Cut the doors last....  after welding up the FB.....  welding the FB "may" warp the CC....  Think about placing the FB air inlets in the door...
  9. Too funny. I was going to pm you.
    My plan is to fit and weld the baffle plate in, then cap the ends and fire box weld end will be same time.
    One question I have is the end of the baffle plate, if my Ed height was 4.5" should I mirror that at the end? For I do it's about 70in sq
    Where my FB cc opening was only 50".
    And Dave, thank you so much for your time guidance and experience.
  10. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    That will be good....  the 180 deg. turn causes a lot of friction...  any relief will improve the flow and temp. evenness across the cooking grate....  You will probably be putting a "dam" across the end of the RF plate to keep grease from dripping inside the CC....   A grease build up could cause an ensuing fire which is not good...   Don't forget a grease drain in the RF plate..
  11. Typically do people run one drain from the rf plate through the bottom of cc, this would inhibit draining of lower portion of CC? Lets say if you hosed it out or had to clean the lower portion?
    I was going to set the CC on a minimal slope away from the fire box, to aid in rf draining. I intended to have a hole in the "gutter" that runs along the center, which would drain to the bottom and then out a 1" pipe with a ball valve. I understand the fire concerns, but is it not needed to drain both?

    The amount of smokers you've had a hand in building is beyond comprehension.
    Thank you again.
  12. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Some folks separate the drains...  1 for the RF plate, it can loosely fit through a hole in the CC...   That loose fit can be used as a drain of sorts....  Also some folks drain the CC through the FB and out when hosing it out...
  13. I now have it all welded and ready to get some legs under her. I have a piece of 3.75 ss pipe 39" long that I'm going to hook up to a plenum at grate level. I'm not sure what I want to do for legs, either have the angled or straight down to a lower shelf.
    I want it on legs, then I'm doing the door.
    Just poking away.
  14. aussiq

    aussiq Smoke Blower

    Wow man thats looking like a sweet smoker. Cant wait to see her finished. Ill be following your build for sure. I like how you cut the fire box into the cook chamber. Is there any reason for this other then to look good and being a stronger join because of slighly more weld. Does your baffle plate sit above the fire box in the cc or does it butt up so that the top of the fire box is part of the baffle
    Last edited: Apr 19, 2016
  15. The rf plate is in line with the top of the FB. I capped the "gutter" for the grease where it meets the fire box. I asked about why people inset the FB, I got a couple of answers.
    1. When using a pressure or prefabed tank, there is a weld seam that makes it hard to fit up, so but inserting the FB you omit the difficult fit up.
    2. Reduces full consumption, helps get more heat into the cook chamber. I was warned it may make that end hotter, which I'm ok with, if I need to I can put a water pan there to help with that.
    Thanks for the positive encouragement.
  18. Need to paint it, put a couple of handles and make my wheels still. It I'm getting closer.
    3.75" id ss chimney.
    meatbox likes this.
  20. Are my pics coming through?

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