80 Gallon completed thanks to all, lots of stolen ideas

Discussion in 'Reverse Flow' started by dougelian, Feb 27, 2015.

  1. A couple of years ago, i started to think about cooking a whole hog for a family celebration, I looked at lots of options, and was going to build something out of cement blocks and expanded metal. My cousin told me a neighbor that had a propane powered rotisserie, and the solution was found. It was a lot of work, but it went over well. I think it was the "show" of the whole hog roasting that made people rave about it, but I just might have pulled it off. In my search for something that I might be able to smoke a suckling pig in, I found this forum. More info here than I have found in days of Googleing (if that is a word). I was looking for jerky spice recipes, and here they are, sauce recipes, and again, here they are, what a wealth of knowledge, and selfless sharing. Thanks to you all. Now, I am certain that smoking Butts, or parts of a pig will be much easier than the whole thing, where muscle groups are thicker than others, have more fat than others etc. The day after the great pig roast i said, i am never doing that again, but maybe, just maybe...

    In a trip to the scrap iron dealer to drop off some iron for recycling I noticed an 80 gallon compressor tank just sitting there. On the way home it was in my truck. We have a 120 gallon compressor here, and I would have much rather have made it out of a 120 gallon tank, but ours has barely had it's first oil change. I thought well, I'll just whip one up, and then if it isn't big enough, I'll just make another one. Well all of you that have built one of these will get a good laugh out of that one... I have sure changed my tune, and have grown fonder of this one with every weld, someone would have to dump a pile of money on me for this one to want to build another. So on to the build.

    Armed with the 80 gallon tank (that I still wish was 120 but I'll shut up about that now), well equipped iron racks from 30 years as a commercial general contractor, a couple of miles of mig wire, and notes from three other 80 gallon builds and both smaller and larger builds from this forum, it all began. I had some things that i definitely wanted, some I knew I didn't. I want to be able to stand right in front of the grille, and not have to straddle a tire, or lean way over. I will mostly use it in our yard, so I wanted  wheels to be able to roll it around. But occasionally I might want to hook it up and haul it over to my brothers, or to the lake, so it needed a hitch as well. I don't see any need for suspension, we haul around compressors and such that just have the axles bolted to the frame all the time, I have only heard of one break, the guy passed me doing about 90 with a mixer on the ball, the next time i saw him, I mentioned about how he blew by me, he laughed and said that when they unhooked the mixer that day, and were rolling it over to the gravel pile, the hitch broke off in their hands, imagine that at 90 right in front of you...Other than that, just a good working unit, got the design down from your pit calculator, looks like I might have to break down and buy some tube.

    Contrary to advice read here, the first thing I did was cut out the opening for the lid, (no guts, no glory). the tank was horizontal and had 4 good legs to get a level start out. Shimmed it so it sat level, marked out the openings, got out the zipcut and presto, the notch for the firebox, and the lid opened. Tank was from pneumatic control system in a large building and as such was well serviced, and drained regularly, (not a lot of rust). You will have to excuse me, I never took any photos of the early stages until I realized the price I had to pay for the information was more information to add to this forum. More cutting, fitting, drilling, welding. We had a rusty 4 x 8 of 1/4" plate in the rack, cleaned it up a bit with the angle grinder and a knotted wire cup, and took it over to a fab shop to have it sheared and broken to suit. I had them put a light hit in the middle of the reverse flow plate, and when we welded in in, we gave it a bit of pressure on the end away from the firebox which resulted in a suitable slope to the pipe we ran through to the outside. I had them cut two 20 x 48 pieces and break them to a 90 in the middle to make it easier to assemble the firebox, put the 2- 90's together, and cap the ends.

    Now before you look at any of the photos, remember to only look at the smoker, my shop always looks like a bomb went off in it, and I usually have a few projects on the go at any given time.

    And, don't look to closely at the welds, I am a carpenter by trade, and a farm boy welder, (I do supervise welders, just make sure they don't see these photos).

    The underside of the RF plate

    I will post more as I have time, smoker is nearly complete, but the photo essay is way behind, till then


  2. Hello.  Looking good Doug.  Nothing beats building your own.  When you finish; that smoker will be worth $250,000,000 to you.  [​IMG]   Have fun and enjoy the experience.  Keep us posted.  Keep Smokin!


  3. In some other threads I noted that there may be a hot spot just over the firebox, so i added a plate that hangs down about 3/4 of an inch runs over the whole firebox top and extends under the RF plate about 10 inches. There is a 1" gap all around the plate.

    Here is the axle, assembled so we can calculate the height of the front wheels

    I originally had wanted to have the firebox open on the side, so that i could tend the fire, and watch the temps from one side. But I couldn't have that and the axle set further back so i didn't have to straddle the wheel. In the end made the firebox door in the back, tucked the lower vents to the back, should have no problem with heat near the tires.

    I wanted to have a ball hitch, and also castor wheels on the front so i can wheel it around the yard, and still hook it up to the truck for longer trips. Our solution was a removable tongue, and removable castor wheels. In this series of photos you will see how both progressed.

    With the undercarriage complete we built a shelf for stuff that extends around the front to make a handle for moving the smoker

    This is our solution to the stack cap, wanted something to hold open and closed (the wind does blow here in Saskatchewan) not necessarily anything in between, but had the mechanism in place so put in another couple of notches.

    The hold open/closed looks a little odd, but remember the radius is from the rod, not the stack

    We definitely had some trouble with the CC lid oil canning, but with some work on the press, and a little blacksmithing, it looks like it should hold smoke. The castors are supposed to hold 600 pounds, they seem like there might be a problem swiveling on the grass, but i have room to cut off the uprights and install larger ones if I have to.

    When we assembled all the parts, some of them needed tweaking, but all told it is what I had envisioned.

    Thanks again to all who provided information, whether you knew it or not, thanks to whoever built this site it is a great resource.

    There is still snow on the ground, but forecast for above freezing all this week, so should get at least the burn in done, maybe more. Thanks again, Doug
  4. Looks awesome Doug!
  5. Looks great. I am about to start on a very similar build. I'm using 2 80g water heater tanks. I'm going to cut out about a third to make it about 7 ft cc. I also have a 50 gal that I'm planning to mount over the firebox that can be used for warming or vertical smoking for links. I am going to build mine on a trailer but loved your idea of a removable tongue. I don't know how many times I've ran to the other side and smacked my chin. Thanks for the idea.
  6. For the removable tongue, we used the same size tube as a truck receiver,and then use the same pin you would use to  hold the hitch in the receiver. We built a few portable toilet trailers for work like this, wanted the removable tongue to nobody could steal them, it works well, and plenty stable at highway speeds. (People always smile at me at the stoplights when I am pulling a toilet on a trailer, like they think I can't control my bowels, and need to be within 10 feet of a toilet...)

    Good luck with your build,

  7. Nice Looks Great

  8. lendecatural

    lendecatural Smoking Fanatic

    That smoker turned out great! Don't let the welders that didn't help critique your welds, they look quite good and will hold just fine. If they pick at you, don't feed them any meat! I'm sure you can't wait to get a fire in it to see how it runs. Keep us posted on how it does and if the temps are fairly even across your cook surface. Again, great job!


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