60 Gallon Air Tank Reverse Flow Build

Discussion in 'Reverse Flow' started by sttimmerma, Jan 18, 2015.

  1. Hello, I recently joined the group and have build  a char-grill out of my old Sears Craftsman 20 Gallon Air Compressor.  It has worked so good, I wanted to take the next step and build a smoker.  Still deciding on the format for it (off-set or reverse flow) My question to the group, the wall thickness of the tank is about an 1/8", I thought it would be 3/16".  My concern is when I weld on the hinges on to the tank it will warp and the lid will not open and close cleanly.  So I was going to weld on a 3/16" strap 2" wide from side to side.  Not sure how it will look, but I think with this I can reduce the warping from the weld on hinges.  (thoughts?)

    Also is there a trip to line up the lid with the opening in the tank?  I welded on to the lid 3/16" x 2" strap. on the lid, so I am unable to ensure the lid is lined up.  I thought about cutting the firebox mounting location into the tank, so I could look up and see how close it lines up on the tank.

    Thanks,
     
  2. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Cut the lid with a disc and angle grinder...   BEFORE cutting it loose, tack weld the hinges in place...   tack weld the seal strapping in place....   you can use 14-16 ga. for the seals...   If you drill holes in the door, next to the cut, or grind grooves in the edge of the door, you can blind weld from the inside of the door...  finish cutting the door loose....  Now, that's not in order but you've got the idea.....  

    Do not weld a full bead....  that causes warping....  skip welding is adequate for most of the welding on a smoker...




     




  3. Thanks for the information....I made fitting the door much harder than it need to be.  I cut the door out completely....I welded a complete bead, I used 3/16" strapping.  Which I heated up with a torch and curved it on the lid.  I will attach a few photos, please feel free to comment.  Thanks,
     
  4. Here is a pic of my twin RF smokers. I used two 60 gal. comp. tanks. They welded up pretty good. I have done 3 to 15 hours and the temp hold at 225 to 300. When I cut my doors they shrunk about an 1 1/2. I just used wider straps.

    <a href="http://s1370.photobucket.com/user/lcjones228/media/Box Smoker/2014-09-22123223_zps5962831a.jpg.html" target="_blank"><img src="http://i1370.photobucket.com/albums/ag265/lcjones228/Box Smoker/2014-09-22123223_zps5962831a.jpg" border="0" alt=" photo 2014-09-22123223_zps5962831a.jpg"/></a>
     
    Last edited: Jan 19, 2015
  5. Did some more work on the grill, wanted to share with you all.  Its coming along, let me know what you think...








     
  6. looking good keep them pics coming 
     
  7. Are you going to make it a reverse flow or a smoker
     
  8. I am planning on making it a reverse flow, but not set if another option would better serve this project?
     
  9. Mine are R/F with 1 1/2 angle in the center with 3/8 plate on each side. Angled higher on fire box side and lower to the other end. I put a drain pipe on the low end. When you weld the plates to the tank use  spot welds 1 inch at a time. weld on one side then the other side. If you run a long bead the tank will warp. I had to learn the hard way. Seal  the fire box side and stop the plates at the curve. You will have about 8" for the smoke to come up.  Check my other post in you can see my pic in case the one above will not work. When I put food on the drippings sizzle on the plates. The plates heats up and the food cooks more evenly and the smoke flavors the meat. The meat will not get dark from the smoke. You can see other sites on R/F smokers or you can PM me for any questions.

    http://i1370.photobucket.com/albums/ag265/lcjones228/Box Smoker/2014-09-22123223_zps5962831a.jpg

    I also used "Feldon's BBQ Pit Builders Calculator" to get the size of fire box and the stack ant size of the intakes for fresh air.

    http://www.feldoncentral.com/bbqcalculator.html
     
  10. A bit more work completed on the grill project today






    A few more pictures and today's progress




     
  11. I have been "stewing" over the firebox dimensions?  I purchased a sheet of 1/4" plate.  Want to make best use of 4 X 8 size.  Originally I was going to make the fire box 18" x 18".  But that would leave me short.  So I decided to make the box 16" X 20" That way I could get three cuts every twenty inches.  Based on the calculations, it's a bit larger than I need.  But I think it would give me a little bit more room for options such a a wood grate or charcoal box.  My question most of the boxes I see are square not rectangle.  Would the 20" x 16" fire box create any unforeseen issues?

    Thanks, 
     
  12. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

  13. Coming along nice, Dave has a handle on the calculations 

    gary
     
  14. The handle I used for the smoker is a 7/8" solid steel sucker rod.  This will work better than I expected
     
  15. I started cutting the 1/4" plate, it's a little less mentally challenging to use the plasma cutter and straight edge, but the overall cut quality is better with less kerf with my 4 1/2" angle grinder.  How did you all make these cuts?
     
  16. I used a plasma cutter
     
  17. Thanks, my plasma cutter may be under-powered, as many of the cuts left behind quite a bit of slag that I will have to grind off. 

    Welding the Firebox= I have not welded a box using steel this thick. 

    Did you all spot weld then go back and weld every other inch, then come back and connect the welds?
     
  18. Nice 

    Gary
     
  19. I would spot weld first, just in case you have to make changes.
     
  20. Setting up to welding the 4 sides of the firebox, I started thinking before doing this, it might be the time to weld on the shelf for the charcoal/firewood?  My dilemma, the idea for the intake was going to be (4) 3" schedule 40 steel pipe 2" long.  My concern if the vents are set at the bottom of the box, the shelf will have to 4+" from the bottom of the firebox.  This will allow the vents to be below the grate for the charcoal/firewood.  Not sure if by doing this I may not be using


      I did make my firebox over sized 20"x20"x20".  Thoughts?
     

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