**New Member = First Reverse Flow Smoker Build from 60 Gallon Compressor Tank**

Discussion in 'Reverse Flow' started by mad dart, Mar 30, 2015.

  1. mad dart

    mad dart Smoke Blower

    Hello all~

    Been lingering for a bit before I registered. Now I am about ready so here we go.

    I just picked up this tank. They are very hard to find here in California and when you do they are still pricey. 

    This will be a back yard patio RF Smoker. Here are some of the features I will be applying to this build.

    1) Single CC Door

    2) Double slide out cooking racks

    3) RF Plate with tub style basin and drain

    4) Double wall fire box

    5) Raised Fire Box Grate with room for ash dump

    6) Fire box vents underneath the fire 

    7) Vent above the fire on fire box

    8) 4" Chimney if the calculations work out

    9) Chimney Flu as per Dave's drawing in the link below. Inlet of Flu at Bottom close to lower rack & Top of flu at Top Rack.

    I have messed around with the calculator on the link below. After I unloaded the tank I forgot to measure how tall it was. Need to do that later tonight.


    I started ordering parts. So far the following is on the way.

    1) 2- Thermometers 3" big face 

    2) 7" Bullet Hinges for the CC Door

    3) 3" Bullet Hinges for the FB Door

    I will be hitting up 2 of my local recycle yards that sell scrap metal by the pound. I can usually find 1/4 plate there along with the other materials I will need. 

    A little back ground on myself. I was a welder/fabricator by trade more than 18 years ago. Now I am just a Hobbiest. I have Mig, TIg & Stick welders, plasma cutters etc and I know how to use all of them fairly well! 

    My idea here is to pre plan most everything, gather all of the materials that I will need and then go into attack mode trying my best to stick to the plan.

    As I go along here, any helpful information will be greatly appreciated. I look forward to getting this started here very soon.

  2. I like watching builds

  3. mad dart

    mad dart Smoke Blower

    Yeah me too! Lol

    I got a bunch of ideas on several different builds that I will be incorporating into this one. 

    Just ordered 5 spring handles for the Lid & FB door latches that I will be making. I will also be using the same handles for the Air vent openings. Still undecided on the way I will be making the CC Door Handle. I have a few ideas, Decisions............... 

    Last edited: Mar 30, 2015
  4. mad dart

    mad dart Smoke Blower

    Question..... I want to order up the seals for the CC & FB Doors . I want to be sure that I allow for any thickness tolerance into the doors to accept a gasket for a super good seal. 

    What is best to use? I found this Lavalock product, has anyone used it?

  5. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    I don't particularly care for bullet hinges... they are unforgiving... they have to be welded in the perfect position or they can skew the door and how it seals....
    that being said, I would weld the door seals in place, weld tabs to the bullet hinges... then weld the hinge assembly in place.... the hinge pin must be "outside" the door seal area to allow for the door to work properly....

    ... click on pic to enlarge .....
    Last edited: Mar 31, 2015
  6. inkjunkie

    inkjunkie Master of the Pit

    Is it done yet Louis?
  7. mad dart

    mad dart Smoke Blower

    Yes I kinda figured they are unforgiving when I purchased them. I Have a little different idea in my head on the mounting that should not require any type of spacing but....... As we all know, an idea in the head sometimes does not work! I'll take a gander at it once the parts get here. If need be I can fab up my own hinges. My plan on this build was to minimize the custom work & if I could buy it, it should make it easy right?? Lol...

    On another note I did measure the tank. Outside dimensions are 48" x 20"
    Last edited: Mar 31, 2015
  8. We'll be watching. We have used bullet hinges in the past, I have them on my smoker, PITA   there are some better alternatives 

  9. inkjunkie

    inkjunkie Master of the Pit

    One thing I have observed about Mad Dart is he is very good at coming up with solutions. Can't wait to see this thing get built
  10. mad dart

    mad dart Smoke Blower

    Well I did some calculating today.

    Volume of the cook chamber is roughly 14000 Cubic Inches.

    14000 x 0.004 = 56 Sq Inches for FB to CC Opening , cut for FB to CC opening will be 16.831" x 4.7085" in height.. I will call it 4.725. 16.831 will also be the firebox width and RF Plate width. 

    This  will also = 56 Sq inches for the area under the RF Plate & also the same with the open area at the end of the RF Plate = 56 Sq inches as a minimum, might go a little bigger, say 58 or so?

    14000 x 0.33 = 4620 cubic inches as a Minimum. Inside I will make mine 16.831w x 18d x 22L measuring from top of the fire grate. I will have an extra 4" under the grate for ash dump etc.

    Double wall finish dimensions will be 18.831w x 24d x 24L , of course this depends on how thick the Insulation I pick up is, I used 3/4" as my number. 

    14000 x .017 = 238 ESV in cubic inches. = a 4" Chimney 18.93" above the CC, I will call it 22", I can always chop it down if needed, I will be using a Plenum. Bottom of Plenum at lower rack, top of plenum at top rack. This can all change depending on what I find for material. 

    14000 x .001 =  14 Sq Inches.... I figure these can be choked off with vent closure so I will be making 3 openings at or below fire level 2.5" x 2" Rectangle, then another round one straight across from the FB to CC opening at 2.5". My fire box door will be on the same side as the CC Door. All vents will opposite of the FB to CC opening. 

    Whew..... That was a lot of calculating. I hope I am right! Lol. 

    I look forward to any constructive criticism or advice. 

    Last edited: Mar 31, 2015
  11. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    MD afternoon..... Now you have a full understanding of your smoker.... that's a lot more than most folks....
  12. lendecatural

    lendecatural Smoking Fanatic

    ^^ Yeah, what he said.

    Additionally, you may want to make that chimney 30", the heat column is what makes the smoker draw so it will breathe a little better.
  13. mad dart

    mad dart Smoke Blower

    Well maybe just a little. I understand the concept and what the end result is supposed to be.... Everything in-between I will figure as I go along with your guys help!
    From what I have read if the Chimney gets too long and away from the calculated length, the smoke can cool off and precipitation can drip back down the Chimney back down into the CC.

    I don't know how accurate that is. I do figure longer is better as it can be cut down.... Too short and you will have to weld in a piece.

    Last edited: Apr 1, 2015
  14. mad dart

    mad dart Smoke Blower

    Spent an hour at the local recycle yards. I found a pipe for the exhaust stack. It is 4.25" inside diameter. Calculator says to make it 16.77" long...........................

    Question...... Can I use it? I will be way out of the calculations if I make it 30" long . Will the exhaust Damper help by choking the bigger pipe off or should I try to find something smaller?

    I can order a 3.25" inside diameter pipe and using the calculations it is supposed to be 28.689" long from top of CC, I would make it 32" or so

    On another note, the better recycle yard has access to getting me pre cut pieces for the RF Plate and the FB.

    The FB will be double wall 3/16 Plate, The whole thing will be double wall & insulated,  the door will be as well, except the bottom. The bottom will have a slide out ash pan of some sort so in a sense it will be double wall, just not insulated....

    The RF Plate will be out of 1/4" material. 

    I did all of the dimensions for the cuts on the Fire Box and RF Plate, that just about drove me banana's, seems easy but it was a brain twister. They say I will have it all in about 1 week after ordering. 
    Last edited: Apr 2, 2015
  15. Which will look better on your smoker ?  You can go shorter with a larger dia as opposed to longer with a smaller dia.  All within reason

  16. lendecatural

    lendecatural Smoking Fanatic

    I would just go with the 4.25  @ 30 without a cap. You want to regulate the air flow by the intake vents, not the exhaust.

    You will be happy with the insulated firebox, much lower wood usage.
  17. inkjunkie

    inkjunkie Master of the Pit

    How does one go about securing the insulation to the inside of the FB?
  18. lendecatural

    lendecatural Smoking Fanatic

    Usually, you build the firebox, weld it to the CC, then insulate the outside of the FB. Some guys tack roofing nails or similar spikes to hold the insulation in place before welding on the outer skin. You can use a strip mounted at a 45 on the corners and weld the skin to that or I've seen guys weld square tubing on the edge to also do the same thing. You can use cardboard to make a template before you cut the skin metal. The outer skin does not have to be as thick since it isn't exposed to the caustic fire environment. If Gary comes along, he did one recently and should have a link to his thread. I suck at digging through the archives.....
  19. mad dart

    mad dart Smoke Blower

    Is this it? 


    The insulation is very dense and comes in 3" plus thickness, can be cut with a fillet type knife. I worked with this stuff when I was in the fabrication field. It can be slipped between the firebox opening as well and it should hold itself in place as long as it is a tight cut and sandwiched in there good. 

  20. lendecatural

    lendecatural Smoking Fanatic

    That's not the one I was thinking about but a good example of another way to do the insulation. The difference in the pre-mounting way is to remember to account for the extra inch of FB height and how to tie it into the CC since it pushes the RF plate up an inch. I believe it was Gary, and the firebox was already built and they decided to insulate after running it for awhile. He'll be reading this thread, I feel confident, he may be cooking Texas brisket this weekend!!

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