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Need to pull the triger on some final things 500 gal RF need some heavy opinions

Discussion in 'Reverse Flow' started by highonthehog, Nov 8, 2010.

  1. highonthehog

    highonthehog Newbie

    Got to busy with life and need to stop and smell the BBQ!  So am about to break into the 500 gal first build been in proses for a few months like most of you gets put to the back burner if you will.  So a few last minute thoughts to bounce off.

    Have a 500 gal on trailer and wondering 

    1: Pros cons of having a fire box or just doing the fire in the corner of the bell with a back hacht and / or side hacht to add to the fire and still doing the RF set up.  Also with doing the fire box the paint will come offer easier or will it do the same with the fire in the tank itself.

          a) also do u think it would take less fire to get it hot being right inside of the tank/ bell roll down and doing the RF thing? food for thought.

    2: Do a grease track with drain or just do a drain at the end in the general area where it will fall and just spray it out.

    3: Propane asist with a turkey fryer tourque to maintane the temp after smoking for the first 4-6 hrs put it just forward of fire area if i dont do the fire box.  or  put it closer tward the bell of were the plate for the RF opens up into the main chamber.

    4.  Last i belive whats your thought on the bottom plate that is bellow the cooking grate to kinda make it like a gaint try so I could fill it with a 2 inches of water if i choose to and it would steam and create crazy moister in the chamber.  But would have a pipe on the one side with a ball valve to drain it/grease.

    Thanks for your help looking to get theis knocked out soon to do two charity events for a church. 

    Thanks again- Jorden 
  2. tom37

    tom37 Master of the Pit OTBS Member SMF Premier Member

  3. highonthehog

    highonthehog Newbie

    Thanks tom I am have everything mapped execpt the fire.  IMHO i see have the the fire box Pros- Can make a large fire easier to get into at add wood a take care of.  Cons - The high heat trapped in smaller space with crapps out the paint job and it looks like crap over time.    Pros for in side imho - use less wood do to the fire being right under the RF plate in turn hold the plate hot/warm provide a warmer raident heat.  Maybe thats my thoughts telll me what u think tom thanks agian for your imput.   or ( everybody else in passing would be great to hear all thoughts and theorys )
  4. tom37

    tom37 Master of the Pit OTBS Member SMF Premier Member

    Here is the smoker that I first learned on. Its my buddies, and it was the first rig he built.

    Here is a shot of the fire box end. It was about 14 tall and maybe 12 wide, it ran about 1/3rd of the way inside the tank, which is a 500 gal fuel tank.

    He had a water tank with slits cut in the top of it, which sat right on top of the fire. Also had openings in the sides for the heat to flow from the sides of the fire instead of straight up.

    One thing is for sure. It worked!!!! And you are 100% right with the thinking of using the hot spot for specific uses. We used the hot side alot for chicken or the misc piece of meat that just wasn't quite ready when turn it was approaching fast.

    The more we cooked the more space we would need. We, on occasion will cook fundraiser events and need every bit of room we can spare.

    It wasn't long and we cut the fire box out and installed a 20" x 30" long side fire box. At this point we had no RF plate, just the water tank. It wasn't perfect but it was alot closer to even temps across the grate.


    And this is a shot of the way we loaded it most of the time. The open door is away from the fire.


    Another thing to keep in mind. Your smoker will grow and change with time. Here is what we are cooking with now days. And I am working on my own rig right now.


    One other thing to remember is that there is no wrong way provided that it cooks.  If you haven't looked yet, in my signature line there is links to smoker builds.
  5. highonthehog

    highonthehog Newbie

    wow that is a amazing rig!  So with a in tank fire it is uneven heat and with a side box better heat flow and even temps?  whats ur thoughts also on RF or not? pros cons.  Thanks again for your help
  6. Dutch

    Dutch Smoking Guru Staff Member Administrator Group Lead OTBS Member OTBS Admin SMF Premier Member

    HOTH-the one thing with a reverse flow is that it will cook faster than a similar sized unit with a sfb.  The drip pan in the r.f. will absorb heat as the heat and smoke flows underneath the pan and then the pan will radiate the heat up into the chamber-think of it as smoking with convection heat. Plus with the pan holding that kind of heat, your recovery time is quicker whenever you open and close the food chamber door.  A friend of mine has a sfb smoker that is nearly the same size as my Lang 60 and because of the convection of the drip pan, I can smoke an 8 lb pork butt in about 10 hours while it will take him just a little over 12 hours for the same sized butt.

    I have closed off my drain and added water to the drip pan to create a moister enviroment-since I didn't really notice any change in the way my ribs and butt tasted I've not done that again-YMMV (your mileage may vary)
  7. highonthehog

    highonthehog Newbie

    Dutch- So u saying with the drip pan + or - cause in theory the RF plate underneth will do the same thing right?  Also Dutch and Tom what size sqaure fire box show i make i also heard its more inportant to have the right size opening into the chamber more? whats ur thoughts. Cheers
  8. tom37

    tom37 Master of the Pit OTBS Member SMF Premier Member

    Dutch is right on with the explanation for the RF theory. With that big of a tank, recovery time will be important.

    If you can swing the RF plate I would do it. If not theres always next time.

    Here is a pit calculator where you can enter your tank size and other info to make it fill in the blanks and let you know what the minimum opens and stack sizes are.

    http://webpages.charter.net/tomchism/BBQ CALC Forms/BBQ Smoker Calculators.htm

    I think that if I was to pick a size I would say to make it somewhere between 24 to 30 inchs square. That would make a great warming space on top of the fire box. If you have any trouble with the calculator let us know and maybe we can help ya out.
  9. highonthehog

    highonthehog Newbie

    sounds great that think is pretty sweet so here it all is! Tank 72,345.6 cb in: Firebox i did a hair larger 36H,48L,48W:  Stacks at 4in 330.19 in: 6in 146.75: 8 in 82.55in of stack does it reall need that much?  Oh alos what did u mean if i can swing it with the RF like cost wise or planning didnt understand? thanks again- HOTH
  10. tom37

    tom37 Master of the Pit OTBS Member SMF Premier Member

    With the RF plate, what I meant was, yes if the money is there along with the extra time and material. Then yes I would go with a RF plate, in the first post you mentioned doing some church events so I wasn't sure how much time you have.

    That seems like a pretty big fire box IMO. The calc is going to give you the minimum specs to make the tank and fire box size work correctly for draft so you don't creosote your food.
  11. highonthehog

    highonthehog Newbie

    Now I have a Qs about the vent stacks A: does it really matter how long there are? B: would it be better to place the stack opening in the bell just above the main grate bellow the top grate because heat rises and by being bellow the top grate it would pull it down and away and out the stack. or in the top corner and have it come into the tank a little deeper to pull the hot air down and out instead of  i have heard about haveing a longer part of the stack in side of the tank for more even flow ? i dont understand how that works as far a better flow.  would like to hear your thoughts
  12. jonnyrod

    jonnyrod Fire Starter

    I think it's better to have a larger firebox as opposed to one undersized. If it is too small it will be a fuel hog, larger than necessary and you will always have reserve heat if you need it.

    The length of the stacks is pretty important to insure proper draw from the firebox inlets through the unit and out the stacks. I am building one now and the pit calculator called for a 55" x4" stack. I didn't want to go that tall so I just made two stacks 30" out of 4" pipe.

    I like the stacks installed flush with the top grate drawing the smoke across it.  My unit is flat capped so I tapped into the sides this was done to allow for more uniform doors and space. With a domed tank, sticking them in through the top portion of the domed end will work great and won't affect your door cutouts. 

    I have a buddy with a big reverse flow and he installed a stick of 4" pipe along the bottom of the smoker from the firebox to the other end. He capped both ends of the pipe and drilled a series of small holes all along the top of it. He plumbed a fill line to it from outside the pit and fills it with water. The end closest to the fire box flashes off the water and he refills as necessary. Just something for you think about.   

    This is all J.M.O [​IMG]