Insulated Reverse Flow Cabinet Smoker Build

[SRPMKR]

I thought I would join the group since I have been reading forum threads for years. I engineered/fabricated this mammoth smoker in part thanks to some other threads on here. When I decided to build a smoker my intention was to build a reverse flow barrel smoker. The more I thought about it the more I realized that it would take up a lot of floor space and not give the greatest amount of cooking capacity. Then it dawned on me that I can go up just like I can go out with the barrel. That's when this bad idea was cemented. I framed this smoker out of 1x1 and 1x2 tube mild steel. The all of the interior and middle divider walls are 1/4 inch steel. I installed an inch of Kaowool insulation and then capped the beast with 1/8 inch steel plate. It has steel ball bearing casters, Destatco latches, and braided rope gaskets. The doors follow this same plan of 1/4 inch inside walls, 1/8 outside, and 1 inch of insulation with 1x1 framing. I had a brain fart with the gaskets, I meant to install them on the doors instead of the smoker itself; just wasn't thinking clearly that day I guess! I was so close to finishing I could almost taste it and made that mistake. The lower pan of the cooking chamber acts as a water pan and is plumbed to the outside for easy cleaning/draining. The smoke chamber is valved as well and I elected to run my Auber PID controller with a 20 cfm fan to regulate the temp. I also built dividers for the charcoal box to progressively burn the coal in the Minon method. I have 5 cooking racks so theoretically I can cook 20-25 slabs of ribs, 10 or so briskets, or a ridiculous amount of butts. The exterior dimensions are 48 inches tall plus 8 inch casters, 28 inches wide, 33 inches deep, it has over 5 MILES of welding wire in it and weighs somewhere well north of 1000 lbs. The only complaints I have with the smoker are the extreme weight and that it takes it a good hour to warm up the massive amount of steel, after that it will cook all day/night. Thanks for letting me join the group and I hope to keep learning from you fine folks....

-Micah

 

[flatbroke]

Welcome to SMF. Great job. You are making the dog drool

 

[JLeonard]

Man that thing is massive. I like it.

 

[JC in GB]

Wow, amazing work. How does the airflow run through that unit?

JC

 

[sawhorseray]

Welcome from Gilbert, AZ! Magnificent piece of work building that smoker, looks like you got quite a bit of practice in on running s puddle. RAY

 

[SRPMKR]

JC in GB it has a valve in the rear of the smoker in the bottom that it draws air inside, or in my case forced in with a PID fan, then flows up a 1 inch camber wall between the middle wall and the cooking chamber wall. The cooking chamber (most interior wall) stops 3 inches shy of the top to allow the smoke to flow into the cooking area, from there the smoke reverse flows down across the meat and mixes with the rising steam from the water pan at the bottom before be exhausted at the bottom of the cooking chamber in the rear and travels up the stack. You can see the gap in the photos on the original post now that you know what to look for.

 

[SRPMKR]

Sawhorseray I might have used a welder a couple times before. This was definitely a different animal though, don't get to run long hot beads on modern vehicles, always have to just stitch those together a tack at a time on the paper thin metal that's used today. I added it up and after it was all said and done there is over 5 miles of .030 wire in it. I built it in a way that the majority of the welds are hidden so it would be as clean of a look as possible when finished.

 

[JC in GB]

JC in GB it has a valve in the rear of the smoker in the bottom that it draws air inside, or in my case forced in with a PID fan, then flows up a 1 inch camber wall between the middle wall and the cooking chamber wall. The cooking chamber (most interior wall) stops 3 inches shy of the top to allow the smoke to flow into the cooking area, from there the smoke reverse flows down across the meat and mixes with the rising steam from the water pan at the bottom before be exhausted at the bottom of the cooking chamber in the rear and travels up the stack. You can see the gap in the photos on the original post now that you know what to look for.

Nice. Thanks for that explanation. Some lovely work you did on that rig.

 

[kruizer]

Look at that!!! A home built Humphreys. Excellent work.

 

[smokin peachey]

Nice work! Looks phenomenal

 

[SmokinAl]

Man that is one awesome build!
Love that shop too!
Al

 

[etotore]

Guess the meat ends up very juicy, easy to keep temperature low enough, with all the insulation? Love the design and the thought gone into it.
Maybe call it reverse gravity feed?

 

[SRPMKR]

Etotore...Yes I can control temps from 150 degrees to 400+. I run an Auber instruments PID controller with a 20 cfm fan. Once I get to temp it never moves unless I open the door or run low on fuel. The only complaint I have is that I built it with two layers of 1/4 inch steel and then the outer layer of 1/8 inch...that is a whole lot of metal so it takes a little time to heat soak that massive amount of steel to get it up to temp. I have learned a few tricks, don't add water until your up to temp because the water will act as a heat sink and hold your temp down for a long time. I have also discovered that leaving the smoke box door cracked speeds up the process significantly. It used to take me 1-1.5 hours to get up to temp and the smoke this weekend took 30 minutes from 40 degrees outside to 275 cook temp.
As for the "gravity Feed" no I wouldn't call it that because there isn't a gravity feed system in place. I load all the charcoal in the box on the bottom. I do like the gravity feed systems and could have intalled that but there again it would have been even more steel and taken up more space. What I love about this is the incredible amount cooking space I have with only 28' by 33' footprint. I could cook 6 20 pound turkeys, 10 briskets, 15 pork butts, 25 slabs of ribs, and i'm not even sure how much yardbird. To get this kind of capacity out of barrel It would take 5 times that amount of space and have to be on a trailer instead of casters. Ribs and turkey are my favorite...here is my Thanksgiving goodness.