The idea was to build as cheaply as possible a BBQ smoker. I wanted something that I could do a whole hog on or just cook some weekend goodies. I also wanted something unique, different, conversation piece, but functional. My material hunt started with finding a tank to make the cooker out of. It didn't take long and I found one. The next step was to build a firebox to heat this tank. I soon discovered steel prices were approaching gold prices :-) Plan B was now in effect. I had to find another tank to make a firebox out of. After several weeks I found one for sale and bought it for about 1/10 the cost of steel to build one. Once I got it home and started looking at what I had I came up with an idea. I would mount one horizontal and one vertical. Part of the vertical would be the firebox and part would be a vertical cooker. So, now I had both the cook chamber and a firebox for far less than buying new steel and I recycled. The only thing left to do was to start building it.

Here I am about to start sampling some goodies off the smoker.

First a safety warning. I used old propane tanks for my cook chamber and firebox. Propane is VERY dangerous. You should seek a professional to render the tank safe for construction. Do not attempt this yourself.

Step 1: Door Cut Outs

After you get your tank back from the professional who rendered it safe, you should mark and cut out your doors. Measure around the tank and divide by 4 to get the dimension for 1/4 of the tank. You will want to mark and cut your doors to be approximately 1/4 th of the tank. This will give you a good opening for your cook racks. Mark the door/doors with a colored Sharpie using a level as required to get a nice straight and level line at top and bottom. I use a fabric tape for drawing the vertical lines for the door as it will wrap around the curvature of the tank.

The door/doors design is a personal choice. Mark and cut whatever you feel will work best for you. I elected to make two larger doors with the little door in the middle (shown cut out in this pic) so that my cook racks could be one piece, slide out, and I would have room to place a whole hog in it without fighting to wiggle it in and around a center piece.

A word of warning here. Don't be surprised if when you cut the tank things warp a bit. This is normal and not your fault. There are ways of correcting this that I won't go into now.

Once you have your doors marked you can cut them out with and acetylene torch, plasma cutter, hand grinder with cut-off wheels, or a sawzall with metal cutting blades. I have also known people to cut them out with a circular saw with a metal cutting blade. I prefer to cut with a some sort of saw as the gap is less in the cut and I don't cut a very straight line with a torch and can't afford a plasma cutter.

Another tip is to not completely cut out your door. Leave some materiel in the corners and middle of the top and bottom of the doors to keep the tank in alignment for as long as possible. You will go back and make the final cut outs later.
That's an awesome build. I love it. Can you post some bigger pictures of the food? I always like the food shots.
I have tried several times to get you some pictures of some of my cooks on this thing. I will try again. Ribs, Prime Rib, Smoked Beer Can Chicken. If you haven't tried smoked prime rib you are really missing out.
beer can chicken is good...
Ohhh, that all looks really good!
Ok, I changed the size of the food picture. Thanks for point that out.
The plenum plate is it a solid piece of steel plate to route the smoke to the far end?
Well sort of. I used 3/16 inch plate but I cut into two pieces to make it easier to remove and clean both them and the bottom of the tank. Some folks will weld this in and make a grease trap and drain into this plate. Either way will work. I line the top of these plates with foil before I cook to aid in cleaning.
you could probably put some of those aluminum pans in on top of the plenum plate. would catch most of the drippings and with the size of the doors you have they should be easy to remove.
Yes, I have done that before also. That is a good idea. Removing the grill's is not much of a problem. The top slides out and the bottom two lift out.
I really love this smoker and I have a bunch of questions!! You stated that the divider plate is about 1/2 inch above the damper, so does the damper swing in our out? Is the whole damper area confined to the plenium area? Could you provide a picture of the completed damper looking through the vertical area into the horizontal area? What a great job you have done on this and I can't wait to build my own Thank you Tracy
The horizontal damper swings into the horizontal tank. Here is a picture of the damper cut into the vertical tank. Picture this vertical tank connected to the end of the horizontal tank. I also included a picture of the vertical damper on the top of the firebox. This is less the linkage I used to connect the damper to the adjuster rod.
<p>This is awesome just what i have been looking for. I think i may give it a try.</p>
Purplewg: or anyone whos done it... iv read thru the plans thouroughly and hate to ask for help if I missed it but any advice or pics for making the damper that is not pictured that allows smoke to go to the vertical tank? What prevents the damper from just swinging shut once you open it Also I dont quite understand what the heat deflector plate is or how it fits in. Any new pics would be much appreciated!
<p>Zach, I built a rotating handle under the vertical damper with a handle that comes out the side of the tank for adjustment. I used bolts that I can tighten or loosen on the joints to hold the damper in place. Just a piece of flat stock bolted to the bottom of the damper which bolts to a piece of flat stock welded to a rod that exists the tank and a handle on the outside end of that. </p><p>The heat deflector is just a flat plate that diffuses the heat coming into the vertical tank. Without this all the heat comes in the damper and runs straight up the side of the tank. This deflector is like a curve in the road if you will.</p>
Thank you sir! I will try and figure out a way to get you a pic of the final product. Should be pretty sweet.
This is so cool!!! How hard are tanks to weld?
Seasoning a smoker is similar to seasoning a cast iron fry pan. Not only does it burn off any impurities it imparts a smokey/oil residue onto the metal creating somewhat of a sealer. It should be done before the first cook and any time it has been cleaned with chemicals or pressure washed to re-coat it. It also prevents rust on the interior. Dry spots are spots that either did not get coated and &quot;seasoned&quot; because you did not get the oil those spots or maybe not enough. They can be recognized as being a lighter color or even dryer looking than the rest of the inside. Hence the dry spot term. I hope this helps.
I don't get what is this seasoning part for. Burning off volatile contaminants made sense, but why the vegetable oil? And what are these &quot;dry spots&quot;?
I absolutely love this, it's a great barbecue/smoker and the project's very clearly presented for others to follow. <br>I've just collected a 47kg Propane cyclinder, this one's destined for a biodiesel reactor, but the next couple will definitely be used for one of these. <br>Thanks so much for sharing this project and making it so clear, it's a real inspiration.
You are welcome. Have a professional open the tank for you.
Hmm, my mind runs in fits and starts..but some bits are starting to fit. <br> <br>What's approximate thickness for propane canisters? My subdivision here in the Philippines is converting to Maynilad (City) Water by the end of the year. <br> <br>Lots o' stainless tanks could be had on the cheap, methinks. <br> <br>My perverse sense of humor seems to insist on naming the cylinders on this sort of incendiary device &quot;Fat Man&quot; and &quot;Little Boy&quot; <br> <br>Clearly the combined apparatus would earn the moniker &quot;Enola Gay&quot; :D <br> <br>I am serious about the stats on propane cylinders, though. I don't anticipate finding a salvageable LP cylinder easily, but the water tank could really rock.. <br> <br>Cheers, <br>Matthew Z
Depending on age and manufacturer they can 3/16 or 1/4 inch. Mine are 3/16. Stainless would be great but I am not setup to weld SS yet. I have seen one that looks like a miniature submarine. lol
What a Great article. Since I was unable to download the PDF, I did a Cut and Paste, text, pictures and all. I have been wanting to build a great smoker but was not sure of the cutouts and placement of all the various pieces. I did notice that the smoker is offset on the trailer. Does this present any problems when you are pulling it from one site to another.
No problems with it being mounted offset on the trailer. I wouldn't make a fast right turn though.
Brilliant idea for total control from hot oven to cold smoking cheese. Great execution and great project explanation. This jumps me a long way toward building my own custom smoker.<br>Thanks very much for taking the time and trouble.
Thank you for the comment. I am pretty proud of it.
I really like the damper idea, reverse flow heat, never thought of that. Keeps the meat from getting too hot at one end of the grill. Gonna see if I can incorporate that idea on my conventional smoker, would have to re-locate the chimney to the other end, not a big deal.. Excellent project, thanks for sharing.
Excellent project but I must say to those less familiar with tank welding: Be extra extra careful when messing up with something that you don't really know much about.<br><br>Don't think water will avoid the explosion all together...Depends what is involved...Some products actually react with water.<br><br>My old employer back in RI told me once he removed the lid of a tank he supposed to weld an the tank was filled with water. He said the explosion made him almost crap on his pants when he landed on the floor on his but...When in doubt with unknown substances wash the tank well before doing stuff like like this and be very careful.<br><br>This tank welding procedure reminds me of another accident that resulted in the dead of the welder in a industrial setting in Portugal... the welder died when he was welding the lid of a bigger tank used to store a chemical component.<br>The explosion pushed the lid and the welder against the ceiling and the welder was crushed in the process....<br>Not sure if he had some common sense, but the truth is people sometimes get seriously injured and worse doing something that does not look dangerous. <br><br>Be very very careful girls and lads!!!!<br>
Nice job man!! I never thought of recycling out dated propane tanks and making something as cool as you have created here.. It's all about tacking something old and outdated, and turning it into something new useful for years to come..I know people who have spent a good amount of money on the same sort of set-up, And theirs isn't even as nice as your rig!! great job indeed man!!!
You could just fill your tanks with water to make them safe for cutting and then drain them. It should be a matter of pulling your valve assembly and a garden hose. No need for a professional to render them safe in my opinion, albeit a lot of water
&nbsp;Fool it is totally necessary for a pro to deem it safe any gas inside that container when you start to cut it will expand and create a volatile amount of pressure and then ....BOOM!!
In all due respect, Rhinowi, you are neglecting some physics concepts and construction logistics. Please, correct me if I'm wrong:<br /> <br /> 1) You would need to create a least few hundred PSI to even trigger the pressure relief valve. All propane tanks have them. It's the law<br /> 2) Speaking of laws,&nbsp; look up &quot;Charles's Law&quot;. You'll need a bonfire get a sealed tank, this size, full of air at zero-PSI to explode. .<br /> 3) Even if after pouring the water out, you screwed the plug back in the tank... &nbsp; &nbsp;&nbsp;<br /> <br /> I'm pretty sure the hole you are cutting in the tank might let expanded air escape.&nbsp; <br />
&nbsp;Pretty sweet man we made one quite similar to this in my metals shop class
This is a great project and instructable. I find I keep coming back to this instructable over and over. I guess it just means I have to build my own now :) I've been looking at propane tank sizes, and I'm just wondering which ones you used. Looking at the picture of you at the smoker it looks to be a good size (compared to your body). I think I may want to use ones that are a comparable size to that. Which tanks did you use? 60 gallon? 100 gallon?
Both tanks are 120 gallon tanks. It is about 24 inches in diameter. This makes for a good cooking surface. If this is too long you can cut the length down and hang a firebox on the end to supply the heat./smoke. Scrape yards, craigslist, and you local propane suppliers are a good place to look.
Looks like a great job. When I weld the door trim on the inside I find it easier to blow holes around the opening, clamp in trim, weld from the outside and grind smooth. I don't like sticking my head in there, breathing the gas and trying to get my bi-focals in the right place. Let's eat!
Thanks KapnKluck, I will sure give that a try on my next one.
nice pig and thank you for the information
You'll love the verticle chamber,if you can baffle and tuneplate it, the temp. should be astounding throughout...
The best one so far. Does the smoke stack by being close to the heat/smoke source affect the amount of heat on the farthest part of the smoker? Since it is hot it will rise faster and exit thru the smoke stack without getting to the farther side, even by shocking the smoke stack because it will exit out the vertical tank stack. You talk about the “heat deflector pleneum” but it is not visible, or explained how it works. The heat deflector on the vertical stack is right at the smoke stack in the smoker, placing the heat right at the exit and not at the “heat deflector pleneum”. Have you check the temperatures at both gages during cooking? I have been designing one of these babies for two years (have not gotten the guts and tools to start until now.) and this one is the best designed/explained I have found.
if you look at step 15 the heat goes under and around the plenum thingy
wouldnt the heat just go up through the verticle tanks stack and not through the horizontal tank? follow the path of least resistance?
There is a damper for both the horizontal and the vertical. If I close the vertical damper down some, the excess heat/smoke has to go into the horizontal tank. The stack on the horizontal tank creates a draft or draw to pull the smoke to it. I hope that explains it a bit better.
My mistake. I thought that the black line pointing to the heat reflector was a piece of metal protruding to the inside the vertical tank to redirect the heat inside the horizontal tank. That takes care of the other questions or doubts. It only remains the”heat deflector pleneum”. I see the blue angle irons, so I assume it is a flat piece of metal is used to direct the heat to the far part of the tank. An incredible instructable. Great job.
Yes, the blue angle iron rails you see are to set the plenum plates on. You can view the plenum as duct work. Duct work will route heat or AC around to the different rooms in your home. This plenum routes the heat to the far end of the tank and then up and back over the food and out the horizontal tank stack.
The principle of having the horizontal tank stack near the firebox is to create the "reverse flow" cooking chamber. The heat is to go the far end and then back to the stack. Yes, the end closest to the firebox is a bit hotter due to radiated heat. This can be resolved with fireproof insulation if desired. I just put the longer cooking meats closer to the firebox. The heat deflector in the vertical chamber has nothing to do with the plenum. The plenum runs in the horizontal chamber. See my other response to this plenum below.
Good Job purplewg
Can you please tell me how you exhaust any smoke from the vertical smoke tube,if the damper prevents any smoke from entering the top of vertical cooking chamber, also what type of material is used for the deflector? You have made one great cooker, im studying as well with plans of one day building my own you have been very helpful Thank You . Before i forget can you tell us or better yet show the red handles are they door stops ??
The damper to the vertical tank when fully closed will direct all heat/smoke into the horizontal cooker. If both are closed then yes, you will get a lot of smoke from around the firebox doors and any place else it can escape to. You should always have one damper at least partially open for correct burning. The red handles you see in the pictures are the external damper adjustment handles. one for vert and one for horiz. The heat defector is just a half moon (out house moon) shaped piece of flat 1/8 inch plate. BTW, I cooked 2- 8 pound Pork Butts and 5 racks of Spare Ribs in the vertical chamber and simultaneously cooked a whole 16 pound turkey, 4 whole chickens, and 4 different kinds of appetizers in it this past weekend.
Those hinges you are talking about are called "Barrel Hinges". I buy mine at the metal shop. A lot easier and faster. You can get different sizes too.

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