New guy first build

Discussion in 'Reverse Flow' started by bishgeo, Mar 10, 2014.

  1. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    .....click on pic to enlarge.......


    Allowing the heat shield to "float" is a very good idea.......

    Dave
     
    Last edited: May 1, 2014
  2. bishgeo,

    I used Dave's idea on my build, for my heat shield it worked amazing. I was able to get an even temp all the way across my CC. Ended up with only about a 4 degree difference from right side to left side.
     
  3. bishgeo

    bishgeo Smoking Fanatic

    Hey Dave , how do you feel about 2" vent holes on fire box so I don't need as many holes. You ran me some figures before for smaller holes. Cc is 20x48 fb is 20x20 I used your figures for fire box to cc opening so loosing that space for deflector plate should be no biggie.
     
  4. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    bishgeo, morning...... HEY !!!!!! I think I confused myself.... I got you mixed up with another member.... Tell me what you are building... sizes.... I see you cooking on a smoker in this thread.... are you building another smoker.... As you can tell, I'm confused....

    Dave
     
  5. bishgeo

    bishgeo Smoking Fanatic

    Yes stick burner if you haven't deleted all your private messages you can re group. 20x48 pipe 20x20 fire box.
     
  6. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    15,080 x 1/3 = 5,027 FB volume or larger is better for long term smokes...
    15,080 x 0.017 = 256 stack volume ... 3 1/4" ID (3" pipe) 36-40" above the CC...
    15,080 x 0.001 = 15 sq. in. FB air inlet + an additional opening of 4 sq. in. across from the FB/CC opening
    15,080 x 0.004 = 60 sq. in. FB/CC opening

    using a radius of 10
    segment height (ED) of 5" = FB/CC opening of 61.4 sq. in.
    chord AB = 17.25" the RF plate width needed to fit 5" above the bottom of the CC....
    +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

    Air inlets for the FB........ You need 12-15 sq. in. ..... 2" hole is (2x2x0.7854=) 3.14 sq. in. .... so you will need 4 each 2" holes for the fire grate area and probably 1 each 2" holes across from the FB/CC opening in the top of the door...

    I apologize for the confusion..... If I knew how many folks I helped daily with smoker builds, I could prove where the confusion comes from.... (old age and getting addled...):th_roflmao:

     
  7. bishgeo

    bishgeo Smoking Fanatic

    I understand Dave I was going to use 1 1/4 but with calculator that called for like 14 holes that's to much. I can go 1 1/4. 1 1/2 Or 2 what would you recommend.
     
  8. Hey guys I was reading above about a heat shield is there a magic length it needs to be

    Am I correct in saying it fits between the fb and cc

    I also read in another thread something about air gap from fb and cc explane please
     

  9. Does this photo represent heat shield and air gap??
    Does heat go above and below this shield?
     
  10. lendecatural

    lendecatural Smoking Fanatic

    Heat goes below that plate and it extends into the CC so the exhaust stack end of the cook chamber doesn't get too much hotter than the rest of the RF plate. Some guys have only 5 degrees of difference when using what is called the baffle plate.
     
  11. Ok but no magic length it needs to be or is that why it's lefts floating so you can pull it in or out to adjust heat flow. You may see this again on my thread I want to keep all this stuff together

    Also seen above that the back of fb is different size than rest. Ok I dumb please explain that one ......
     
  12. lendecatural

    lendecatural Smoking Fanatic

    I don't think there is a magic number for length into the cook chamber. 


    I think what you are seeing is the difference because of where it fits within the arc of the FB cutout where it fits up to the cook chamber as shown in this photo. Hope this helps.
     
  13. bishgeo

    bishgeo Smoking Fanatic

    . Maybe it will make more sense in this pic baffle plate has to be not as wide to fit thru smaller area of half moon opening. Mine is only extending 4" into cc. You can go 12" if you want. Rf plate will weld to top of fb above baffle plate.
     
  14. So the shield is more or less pushing the heat on down the cc and length also in fb isn't as important either

    Question someone said it was good idea to not weld this shield what is the benefit

    sorry for all the questions
     
  15. smokejumper

    smokejumper Smoking Fanatic

    It is best to let the heat shield float.
    The benefit is that it allows the shield to expand and contract without pushing on anything else.
    In this case it also has the added benefit of allowing a longer or shorter (or none) plate to fine tune the heat distribution across the CC.
    Sometimes it is good to have a hot spot (for chicken for instance) while cooking other stuff at a lower temp.
     
    Last edited: May 1, 2014
  16. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Air inlets for the FB........ You need 12-15 sq. in. ..... 2" hole is (2x2x0.7854=) 3.14 sq. in. .... so you will need 4 each 2" holes for the fire grate area and probably 1 each 2" holes across from the FB/CC opening in the top of the door...
     
  17. bishgeo

    bishgeo Smoking Fanatic

    Got the fire box on.



     
  18. newsmokeguy

    newsmokeguy Smoke Blower

    Nice!
     
  19. bishgeo

    bishgeo Smoking Fanatic

    Went shopping today sure don't look like #140
     
  20. lendecatural

    lendecatural Smoking Fanatic

    That is some seriously strong rectangular tubing, you could pick up the 8,000# Dodge with that!
     

Share This Page