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new 250 R.F build

Discussion in 'Reverse Flow' started by moparman33952, Sep 3, 2010.

  1. OK I finally got my tank this is going to be a VERY slow  build of a 250 Gal. R.F. trailer mounted smoker as I have too many projects at this time ( boat , jetski, two trailers one for the smoker other personal ) I'm saving up to buy enough metal  to build a couple trailers and get my other projects going  I will post QVIEW pics as this biuld progresses as ya'll can see I have started laying out the doors [​IMG]
  2. dave54

    dave54 Smoking Fanatic

    good start

    don't forget measure twice,cut once

    and lots of pictures[​IMG]
  3. Thanks Dave yes I will definitly measure more than once just laying it out so far to get an idea of how things will look I still have to drain her out agian and level her out to get a better look and finalize the measurements. more pics will follow as it progresses  i can't wait already ordered hinges and spring handles
  4. bob1961

    bob1961 Smoking Fanatic

    yeah don't do the........bob

    " i cut it twice ? , and it's still too short ? "

  5. Had time to do some work on my build. I got the doors cut & framed, hinges on, fire box opening cut ; left room for more cutting if needed ( learned this after cutting the door height  twice )  fire box cut and  welded up, door cut ,framed, hinges welded on bracing partially installed in the f.b. door.

    hopefully gonna set the tank on the f.b. this weekend to finalize the dimensions on the f.b. opening   [​IMG][​IMG]  [​IMG][​IMG][​IMG][​IMG][​IMG][​IMG]
  6. raptor700

    raptor700 Master of the Pit OTBS Member

    Comin' along nicely  [​IMG]   Are the hinges for your FB from KcK ?
  7. tom37

    tom37 Master of the Pit OTBS Member SMF Premier Member

    Looks like you are coming along nicely. I'm looking forward to seeing it progress.
  8. smoke_chef

    smoke_chef Smoking Fanatic SMF Premier Member

    Looking good!!!
  9. Hey Raptor yes the hinges are from KCK  I also used them on the doors love them best of all they are greaseable. Thanks everyone for the compliments it makes me that more pumped up to work on it, now off to order more steel to fab up the grates, grate supports, charcoal box and box support, gonna make everything slide out (easy access ).. before I go for now I have a couple questions 

    first is I used the pit ratio calculator and came up with the dimentions of 28"w X 6" t for the f.b. to pit opening which is for a rectangular opening. Though I realise I wont be able to get a perfect rectanguler opening and it really doesn't give options for a quarter round opening ( or I don't know how to get this dimention)  I do have room to move my f.b. up about an 1" if needed (which I think I need to ) my question is can I use these dimentions by following the contours of the tank on the sides without the 1" of extra height or do I have to raise it to compensate for the sides ( tank contour )

    second question is I plan to have my R.F. plate about an 1" above my f.b. with about a 1/4" drop towards the non f.b. side  now  IF I measured everything correctly ( I hope so ) this leaves me with about 4.5- 5 "  from the bottom of the grates to the top of the r.f. plate  is this too close?? or about right??   I do plan on using the f.b. to tank cut out peice as an adjustable damper to help control airflow  as well as a damper in the exhaust stack.

    thanks in advance for all your advise and recommendations 
  10. raptor700

    raptor700 Master of the Pit OTBS Member

     Just my .02  Hope it helps....
     That is the way I built mine, 4.5 in from the grate to the RF plate. And it works great.
     Me Personaly, Once I cut my FB to cookin' chamber out, I used the same sq in. on the end of the RF plate. And also used the same sq in. on the exhaust stack.
  11. Thanks Raptor from what the calculator came up with for the cooking chamber opening was 173sq.in. and exhaust vol. Was 1080 cubic in. Or a 6" stack at 38.2" in length. Now I admit I ain't great at math thats why I'm asking. Most of the posts on here say the rf opening should equal the cooking chamber opening and then most all say that the ratio calculator should be followed.which is why I'm asking; the more I think about your last post it makes more sense now. I shall make the necessary mods. I was just confused on the c.c. opening

    Thanks Raptor
  12. raptor700

    raptor700 Master of the Pit OTBS Member

    No Problem Moparman, I actually made my exhaust stack a little longer than needed. I wanted  to get a good draw threw the CC and I can always slow the draw with my damper. It's easier to slow the draw than speed it up. Once the heat leaves the stack there is no more draw!
  13. Very true once again thanks
  14. tom37

    tom37 Master of the Pit OTBS Member SMF Premier Member

    Not sure if this will help or not.

    If you had a 30" dia tank and the top of the fire box was 5" up from the bottom of the tank, you would have 77.4 sq in of area. Here is a link and a pic of a circle calc that I use. Select radius and segment height, then you can look at the area in the lower boxes. I just play with the segment height number till I get the area I want.

    Circle Calculator


    What is the aprox. dia of the tank you are using?

    I get a figure of 9 in tall and a 30 in dia tank to = 178 s in of area.
  15. Thanks Tom I give this a visit,I wanted to ask and verify before i actually made the c.c. openeing. I will use this calculator to get my measurements, I had forgotten I had bookmarked this site once again thanks
  16. rbranstner

    rbranstner Smoking Guru OTBS Member

    That is going to be one heck of a smoker. I wish I had the skills and equipment to make my own smoker like that. 
  17. Thanks the only tools I have are a snap-on 140 amp welder, 7"angle grinder and  a 14" metal chop saw, though I am a body man by trade I do love building things as a hobby. I just bought one of them there taiwan made plasma cutters today off of ebay I hope it is a good $300 investment

    Hey Tom I'm still a little confused as to the measurements in the calculator I admit I'm not exactly sure as to what I'm looking at which makes it even more confusing but if I measure 9" up from the (inside ) bottom I'm not to sure I'll have enough room. I seen in the example you provided you gave a radius of 15" and yes my tank is 30" in diam. now at a height of 9" tall for the opening that is a little under half of the 24" height of my fb seems like a lot to cut out of the fb
  18. raptor700

    raptor700 Master of the Pit OTBS Member

    Just throwing this out there! When I built my 250, I measured my friends lang and it was 9" from bottom. Mr. Lang can't be wrong!!!!
  19. Thanks!!! just went out and re-measured things and all looks  just had a mental block a severe one at that once again THANKS
  20. tom37

    tom37 Master of the Pit OTBS Member SMF Premier Member

    9 inchs did sound like alot when I read it today but then I started thinking about it and you do have alot of volume there. Please keep us posted with progress.