275 gallon tank smoker

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johnman6996

Fire Starter
Original poster
May 9, 2015
34
16
So, I got a 275 gallon oil tank all prepped and ready to go.  I put three doors on it.  Two horizontal doors and one big vertical door.  I'm getting some flat stock to put on around the doors to help  seal it.  I'm debating on where to put the fire box.  Part of me wants to do the traditional side mount box, but a HUGE part of me says to mount it off the back. 

After researching store bought smokers I started watching videos on "The Good One"s website ( http://thegood-one.com/ ).  I am intrigued on how they used the shape of the smoke chamber to force the smoke to circulate in the chamber itself.  I was thinking that a rear mounted firebox could utilize the shape of the tank to do the exact same thing.  I was thinking about either flush mounting the stack dampers on the existing holes (kind of like they do on their smokers) or dropping a pipe down into the chamber itself 6"-10"  Thoughts?








 

Here is a picture of the design I'm thinking of.  Any input?  I didn't have time to save it properly, I had to take a picture of it with my phone rather than upload it to my OneDrive because I had to get back to work.
 

I decided not to get fancy with the smoke box placement (mostly out of necessity).  Take a look at my design of the firebox.  Anyone have any input that has used a 275 gallon tank as a smoker?  I used Feldon's calculator and over sized the box, air intakes, and inlet to the cooking chamber about 20%.  I'm going to try and have this fabricated next week.  Any input would be great!  Nothing is to scale and I used MS Paint for the mock up.  Stock is going to be 1/4".

Thanks and God bless!

~John
 

I have the expanded metal to make the racks now.  Anyone have any input on the placement of the metal?  Should it lay on top of the angle or rest in the channel?
 
I had to do an in-chamber smoke. 42 slabs. Going to get the third rack and firebox done over the next few weeks. Made my own rub, tasted pretty good. Going to do a couple more smokes before I sand and paint. Looking into the Raspberry PI fan/temp controller. Going to add a 120MM fan to the PI controller. Going to be a fun winter! I smoke at least 40 slabs a month and going to keep it up over the winter as long as demand keeps up. Going to do 20 turkeys for Thanksgiving. Enjoy!


 



I finished the vertical part of the chimney.  I set a piece of angle stock on top of the chimney to show how I am going to cap it.  I figure with some left over scrap from the chimney welded to the angle stock it will look like a roof on a house.  I am debating on how to mount the cap.  Part of my wants to use the left over square pipe that I used for the hinges and some more round stock to allow it to slide up and down.  That way I can adjust airflow if I need to.  Figure some cotter pins through the round stock would do it. 

Thoughts?

I used Feldon's Calculator to figure out the length of the chimney when it came to overall area.  The hole in the smoker had the same area as an 11" pipe.  Had I used and 11" pipe as a chimney it would have had to be about 13" long.  The overall height of the chimney from the base of the bend to the top is 12".  The shortest part of the chimney mounted to the side of the smoker is about 4" or so.  The chimney itself is A LOT bigger than the hole to the chamber (by design, I can't weld very well and I wanted it to be an easy mount).  So, I figured that with the loss of area with the smaller part of the chimney and the much larger part that attaches to the chamber it would all equal out... but, I sell computers for a living and don't know engineering.
 
Air flow is highest thru a round pipe. Any time you use rectangular you add friction loss. Add roughly 15 - 20% to the round stack length and it'll be close enough.
 
The length of the entire "L" is about 20" -22". That puts it about 3" - 6" too long (when adding the 20%). We'll see how it goes when I smoke another 40 slabs next week.

The part of the stack that goes vertically reduces the area of the opening to the smoker by about 15% (86 square inches vs. 74) so I hope it ends up being a wash.
 
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Also, I want to angle my baffle plate to have a trough in the middle and an outlet that I can drain for easy cleanup.  I have a plate already that will suffice.  I only have an angle grinder and SawsAll for cutting though.  I was thinking about making a trough like the one in this video:



Has anyone done one of these and has any input on how to go about it?  I don't have a plasma cutter so my cuts will be wavy as all get out.
 
Are you still working on this build, I was interested in what you came up with on mounting to a trailer? I see someone recommended the Harbor Freight trailer, I was looking at their 4x8 trailer for a similar size smoker and wanted to see one first.
 
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