My first tank type RF Smoker

Discussion in 'Reverse Flow' started by mr big d, Jan 22, 2012.

  1. After a lot of looking threw the smf forum i decided to try build my own. I didn't need a real big smoker and i got lucky and came across a 80 gal air compressor tank that was out of service. My plan is to make it a RF type smoker on a small trailer.I found a trailer but i think it will be way to wimpy,i plan on two inches of insulation around the fire box as it can get kinda cold up here in the winter ,that when i will have the most time to do some smoking.I have read a lot about gas in the firebox and under the plate what are your thoughts on this ? Here are some pics.[​IMG][​IMG]

    Drawing for my door [​IMG]

    Door hinges made out of 3/16[​IMG]

    Door is 1/4 the cir of the tank,decided to go off dead top center ? not sure if that's right ,but it's done. The first few cuts i was

    vary nervous, I did not want to make any mistakes !!!

    Last edited: Feb 20, 2012
  2. solaryellow

    solaryellow Limited Mod Group Lead

    Great start! Can't wait to see what you do from here.
  3. shoneyboy

    shoneyboy Master of the Pit OTBS Member

    Nice start....Keep us posted....
  4. scarbelly

    scarbelly Smoking Guru OTBS Member

    That is going to be a nice smoker the way you are going 
  5. Looks the hinges..Im on my second trailer smoker now and its a the non rotisserie one I have a tube that my burner blows down with a baffle at the end and for my burner I actually used something close to a boiler burner..
  6. raymo76

    raymo76 Smoking Fanatic

    Looking good, this should be another fun build to follow!
  7. Good start. This is going to be a great little smoker build to watch.
  8. tyotrain

    tyotrain Master of the Pit

    Great job looks like its going to be a great smoker... can't wait to see it all done..[​IMG]
  9. Got some more pictures . Cut end out and burnt out the tank .[​IMG]

    Burning out the Tank [​IMG]


    Rob My son-in-law came to help this weekend. He's cutting out part of the flow plate[​IMG]

    The flow plate is a 5/16 plate.We bent the middle down with the press about an 1 1/2 inch's.[​IMG]



    Before I weld the plate into place I need to know if I should put a pipe burner under it ? I think I will work on cutting out the fire box before I get ahead of myself . I also need to cut a drain hole near the end of the flow plate. I'm going to make the firebox out of 5/16" steel also. And my plan is 20"high x 20"long x 18" deep. I will have a 4" chimney I'm not sure on the opening from the fire box under the flow plate , if I use a damper under the plate can I get by with a bigger opening ,like 18"x4 or 5 inch's ?

    My fire box will have six 2x2 square openings for air. I did the calculator but I would like some one to tell me if I'm on the right track?

    Is this to many pics ?
  10. fourthwind

    fourthwind Master of the Pit OTBS Member SMF Premier Member

    The size of the air inlets, and the gap at the end of your RF plate will depend on the size of the exhaust.  My spreadsheet (modified for RF smokers) says you want to use about 18 inches of five inch diameter pipe.  that will mean you will need 30 sq inches of air inlet, and 25 sq inches of gap at the end of the RF plate.   

    The 5/16 RF plate is way overkill IMHO.  

    If you are still going to insulate the box, I recomend using 1 inch thick ceramic wool.  stuff works awesome.  2 inches would be way overkill.  We did a smoke on one that had a 1/4" internal wall, 1 inch insulation, and then 1/8" outer wall.  There was frost and light ice on the outside before we lit the fire.  took an hour before it melted!
  11. Now i am a bit confused. I used the calculator that's been used on this site and others , it tells me if I use a 4 inch ID pipe for my exhaust it has to be 28.66 inch's long I plan to put the bottom of the pipe just above my lower cooking grate. Will that work? The calculator states i need 57.6 Sq in of opening from the firebox.  I also found a ellipse area calculator for the odd shape from the fire box . if I use a size of 18x5 = 70.68 if I use 18x4.5 = 63.3   http://csgnetwork,com/areaellipse.html   How about my other calculations firebox size and air inlets? 

    I agree 5/16 is over kill I'm just using up some left over peaces from other projects, and what ever I can get Farly reasonable priced from our scrap yard.

    Thanks for your help I don't want to screw this up!!!
  12. fourthwind

    fourthwind Master of the Pit OTBS Member SMF Premier Member

    Most of the calculators available online are set up for standard airflow configurations.   Lets just say mine has been tweaked to suit reverse flow. [​IMG]   

    The length of the pipe that is suggested is what is exposed outside of the cook chamber.  I would take the pipe down into the chamber to about 2 inches above the lower rack.

    It looks like 60 sq inches would be plenty for the firebox to cook chamber opening.

    25 to 30 square inches of air inlet to the firebox should be enough.  If your under 3000 feet go with the lower number, and if your above, go with the higher number.

    Dont worry about being super precise.  Better to have larger airflows that can be choked down than to not have enough.
  13. Fourthwind : Thank for the help, I thought I was way off , If I.m putting this much time into this smoker I hope it works like it's suppose to , It sure makes it nice for us guys who like to try build our own , that you and others have worked out the right and wrong way of  building them. Someone should put together a calculator for RF there seems to be a lot of this type being built. The ellipse area calculator also helped out on the odd shape 1/4 moon openings. If you see something not quite right with my plans or have a better idea please let me know. 

         Did some more work on the door trim and started welding up the firebox. you can see some splicing in the fire box just using up pieces around the farm. the 2x2 openings are cut up from a old field cultivator . I know it way overkill but it's what I have.

        This is whats for Dinner chicken brests wraped in homemade bacon and rubed down with jeffs rub.


     Door frame inside tank


    I'm happy with how the door turned out



    Firebox 5/16 plate




    Six 2x2 air vents

  14. fourthwind

    fourthwind Master of the Pit OTBS Member SMF Premier Member

    We can just nick name you Captain overkill!  =)     It all looks like some great handy work.  It will serve you well when its all said and done.  I would lip the outside of the cook chamber door as well.  We skip the inside unless requested by the customer, but doing both should get you a great seal.

    The chicken looks like it would be awesome!

    Look forward to seeing the next progress.

  15.   I guess I'm going to have to take that nick name especially after you see this. I picked this boat trailer up the other day for $250.00 I just couldn't pass it up.It had a 19 foot boat on it at the time with no motor or seats etc. and I know it will be overkill but it should hold my smoker anyway.I got started right away here some pic.


    Another sweet thing about it is it was only 15 miles from home.


    Dad giving a helping hand.


    Made some new shackles and welded them into place.


    Cut the axle,square tubes and hitch poll.




    Welded the axle back together put a smaller tube inside this one for more strength


    This was plan A but I think overkill with plan B !!! will work much better.


     Had to put new seals in the hubs and repacked bearing. it should last many years now , I will only plan to take it to the lake once awhile.

    Ran across this in Jamestown last weekend , I could have mounted the smoker on the back of this . You know your a redneck if your smoker has its own drive train.

  16. fourthwind

    fourthwind Master of the Pit OTBS Member SMF Premier Member

    LOL  I think the small truck would have been awesome!       Too bad you didn't live down here.   I could put your skills to work every now and then!
  17. sunman76

    sunman76 Master of the Pit

    oh that is going to be anice smoker!  and yea on the mini truck smoker that would be awsome.....[​IMG]  If i had the money I would build one that would be just to cool to have a drivable smoker!
  18.   Finely getting back to work on my project. I have got the firebox completed , the gate between the firebox and the cook chamber done and started on the outer shell if the firebox . I have decided to put a pipe burner in the firebox . that didn't go quit as I wanted . I was going to put the pipe between the two walls of the smoke-box but I did have enough room so it will have to go on the outside its OK just doesn't look as nice. Found a firebox door off a scraped out wood burner. I think it will be big enough 14x14







    Two inches of high temp insulation. That firebox will be still hot a week later.


    After I get the outside shell welded up then I'm going to get back to the cook chamber, the smoke stack, Door handle,then the trailer. Still have a long way to go.

    I will awhile before I get to working on it We are off to get some sun before springs work begins. Although it's been one of the nicest winter it still is going to fast !!!
    Last edited: Feb 20, 2012
  19. fourthwind

    fourthwind Master of the Pit OTBS Member SMF Premier Member

    Looking good!
  20. smokingohiobutcher

    smokingohiobutcher Master of the Pit OTBS Member

    WOW!!! Now I really got the bug!!! Smoker looks SOOO overkillingly awesome!!!

    Great job! Is the pipe burner to be used as a log lighter or a alternative heat source?

    Another guy used a weed burner mounted to the outside of his fire box as a log lighter...thought that was a sweet idea!

    I'll have to see if i can find that post.

    Keep the pics coming!


    Here it is...burner info starts on page 4.
    Last edited: Feb 21, 2012

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