--(UPDATED 3/20/11) Reverse Flow Smoker on Trailer- 80 gallon tank, NOW WITH PICS (beginings)

[azbbqguy]

So here it is I’ve decided to go ahead and build my smoker. I wanted something that I could take camping with me and while I’m spending a few days in the woods I will be smoking my brisket of shoulder. So I acquired this 80 gallon tank (former devilbis air compressor tank) for 40.00 from an old guy and the trailer (former welder trailer) it’s going on for free from my dad. I’ve gone back and forth trying to decide if I should do a traditional reverse flow design or doing something a little different by putting the fire box under the tank in the middle, still having the RF plate just having a gap on both sides for the smoke to roll around and having the smoke stack in the center of the tank above the fire box. I like the build Uncle Beef did a lot I wanted to ask him how even his heating is, but I can’t seem to get ahold of him-. So I’ve cut the doors on my smoker using a sawzal which worked surprisingly affective, I used a sawzal because I was unsure if there was oil inside the tank and so I didn’t want to use a torch. When the tank was cut open I found a lot of rust inside, so I filled the tank full of 3/4 gravel and bricks and pulled it around my yard with my quad. As the tank would spin the rocks would knock a lot of the rust off the inside off the tank. Next I super-heated the remaining heavy rust with my torch, causing it to flake off. Then I burned out the inside of the tank for several hours to get any chemical residue out. The tank has a welded on tag with the manufacturers name on it. I’ve decided to keep the tag and have it right on the front of the cooker as a tribute to the manufacturing era in this country that has disappeared over the last 50 yrs. Tonight I cut the trailer down where I can start lengthening it to where I’d like it. I am going to have a charcoal grill and two heavy duty propane burners at the end of the trailer behind the smoker. So I’m going to lengthen the trailer to about 8-9 feet from 4 foot where it is now. I was going to add a propane gas assist, for lengthy cooking times, however I read about a guy who had a propane assist on his cooker the gas leaked into the cook chamber and caused the smoker to blow up like a bomb, so I’m having my doubts about adding the gas assist. Anyway here’s the pics Any aDvice on my project is very much welcomed

 

[sqwib]

Sounds like Frank

Frank has 2 propane burners and so far no problems

 

[ledhead84]

Sounds like a good build.

The middle firebox sounds interesting, it would make it very efficient since all the heat will go up into the cook chamber and be dispersed by the RF plate. You might be able to get away with a smaller fire....just a matter if it would be too much heat?

My biggest concern would be keeping both sides even you wouldn’t' want all the smoke going out one side and not touching the other. It might make it hard to balance the heat on both sides. Maybe a baffle in the middle that you can direct heat/smoke to keep both sides balanced could work?

 

[real57vetteguy]

Sounds like we are on the same page! Have you looked at my build? Mine's just some old junk thrown together, but the more I look at the middle/lower fire box the more I like it, we cut in a dampner, but the heat transfer its self will be awesome. I also did a reverse flow type plate leaving both ends open and we are going to put the stack in the middle just at cooking grate height! I havent seen a build like this anywhere but I am excited about it!

 

[j-rod]

I also like the idea of the middle firebox with a baffle that allows the heat/smoke to work around both sides. You would prob get very even cooking on both sides. I would imagine that the stack would have to be located in the center of the tank but I have never seen a build quite like this so it is just a guess. I would also guess that the smoker itself would need to be level when cooking to ensure the heat doesn't run along one side of plate predominantly. Just a couple of ideas, could be dead wrong. I just finished a reverse flow with an end fire box and so far I have experienced even temps on both sides (within 5-10 degrees) so I think you will be pleased any way you go about it.

 

[real57vetteguy]

I also like the idea of the middle firebox with a baffle that allows the heat/smoke to work around both sides. You would prob get very even cooking on both sides. I would imagine that the stack would have to be located in the center of the tank but I have never seen a build quite like this so it is just a guess. I would also guess that the smoker itself would need to be level when cooking to ensure the heat doesn't run along one side of plate predominantly. Just a couple of ideas, could be dead wrong. I just finished a reverse flow with an end fire box and so far I have experienced even temps on both sides (within 5-10 degrees) so I think you will be pleased any way you go about it.

 
I agree, and leveling is a big part, we talked about leveling devices on mine, but I felt too much on the build will make it look trashy, I might just level mine with shims under the tires, we thought about pipe jacks under each side and a deflecting moung to the axle. I also agree the stack needs to be center and on top of that at cookinggrate height to draw the smoke/heat right across the cooking grate. I dont think a radius would be the best for the stack, just a clean short 90 bend out then up

 

[SmokinAl]

It sounds like a lot of work, good thing you have a good helper!

 

[azbbqguy]

Yea vetteguy I saw yours it looks super cool, . My only concern is as the smoke rises up out of the fire box it would need to split so some goes to the left of the chamber and some goes to the right, I dont know if smoke splits like that or mostly just stays together, thats the only thing holding me back on doing a centered fire box.

 

[justpassingthru]

I like the fire box under the smoking chamber idea, how about if you built a triangular shaped diffuser at the top opening of the fire box, you could even add an adjustable baffle on each side that you could use to regulate hot air flow to even out the heat in both sides of the cooking chamber.

Personally I think this design would be very fuel efficient with the majority of the heat transferring into the cooking chamber.

Don't give up, there's a way to make it work.

Gene

 

[fpnmf]

Looking good!!

 Have fun!

  Craig

 

[real57vetteguy]

Yea vetteguy I saw yours it looks super cool, . My only concern is as the smoke rises up out of the fire box it would need to split so some goes to the left of the chamber and some goes to the right, I dont know if smoke splits like that or mostly just stays together, thats the only thing holding me back on doing a centered fire box.

Well, there is only one way to find out! I will be firing mine up in a few days, so if you havent decided what to do by then I can certainly take a vid or post some pics of how it works and we will see in the seperation is equal or not, but I certainly hope so!

 

[azbbqguy]

Definaltly let me know how it works-

Sean

 

[sqwib]

With the center firebox will you leave both ends open for the reverse flow plate?

Would a center stack help with the flow?

 

[real57vetteguy]

Azbbqguy,

We test fired mine last night, if you check out my thread I put some detailed temp info up last night, I highly recommend the center firebox. I was overly impressed at how even the temps were and how easy it was to keep at consistant temps. now I havent used wood yet my test last night was on propane!

 

[azbbqguy]

Yea I saw your thread that pit looks pretty sweet! 

 

[azbbqguy]

Ok I finally pulled the trigger and commited to a traditional style reverse flow.  So heres the updated pics. Just welded in the RF plate and angle iron for the grease trap, I still have to grind off some slag and berrys from the weld, Keep in mind this is my first big welding project so the welds aren't to pretty, but my dad welded some and his look much better than mine. Does anyone know how much fall there is on the angle piece thats a grease trap, it obviously slopes to the drain on the far end, but how much? Mine sloped like 3/4 of an inch over 52 inches-  Anyone know a good way to get that welding flux residue out of the cooker?

heres the updated pics

 

[SmokinAl]

Man it looks excellent so far!

 

[chefrob]

good start....where are ya at in az?

 

[scarbelly]

Great looking start

 

[tom37]

Looking good man, your moving right along. 

Are you using flux core in a wire welder or are you talking about the flux of the stick rods. 

I'm just asking since in the pic it looked like I saw lead and an electrode holder but in the background I saw a miller 185.

With the flux wire just use a knot wheel on the grinder and it will clean the weld nicely.

The stick rod usually will chip off pretty easy. 

Either way once the chunks are loose, you can flush it out with water and the pieces should wash right out. 

The smoke residue shouldn't be much of an issue either. I can't say that I have ever worried about it much myself but I would think the carwash would get it out pretty good.

A couple nice burns and you won't ever see the residue anyways. 

Not that its right or that I would try it, but I have seen guys take a brand new galv trash can and season it once and then smoke in it. They said WELL the galv is covered up with seasoning. You would be amazed at the things you will see.