# Reverse flow build



## cysmoker (Jun 4, 2019)

Finally decided it's time to build my stick burner. Currently I smoke on a Green Mountain, Rec Tec, or my PK but I want something I can play with a little more. 

I picked up a 60 gallon air tank (20inx44in) and a 15 gallon air tank. I did all of my calculations based on DaveOmaks thread, and came up with the following:

FB/CC opening = 55.44 in
Area under RF plate = 55.44
Area at end of plate = 55.44
Air intake area = 13.86" (will do around 3" for the upper and 11" for the lower)
Exhaust stack volume = 305 cubic in
Exhaust Stack = 4" diameter by 24" height
RFplate width = 17"
Height of FB/CC opening= 4.75"

Do these numbers look accurate? The only other question I have is on my fire box. My 15 gallon tank is a little smaller than suggested. A 20 gallon would have been better but I couldn't find one for a reasonable cost. Will the 15 gallon tank be a problem or should I fab one up out of steel? Looking forward to getting this thing up and smoking!


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## daveomak (Jun 4, 2019)

15 gallon FB will work...   The metal thickness of an air tank is pretty thin...  Just beware of that...  
All of your work could only last 4-5 years, depending on usage...
For the exhaust stack, it should be lengthened to ~ 34", so it has enough "SUCK" to promote good air flow through the smoker..  The 4" diameter should work OK...


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## cysmoker (Jun 4, 2019)

daveomak said:


> 15 gallon FB will work...   The metal thickness of an air tank is pretty thin...  Just beware of that...
> All of your work could only last 4-5 years, depending on usage...
> For the exhaust stack, it should be lengthened to ~ 34", so it has enough "SUCK" to promote good air flow through the smoker..  The 4" diameter should work OK...



Thank you sir. These tanks are thicker than I thought they would be from the looks of it. I haven't cut into them to put a gauge on the wall thickness but the guy I bought them off of had planned to also build a smoker and had started making a cut for the door so I could see the thickness a little. I didn't like his positioning so i welded the cut back shut (about 8" long is all it was). I'll most likely be bored of it and want something different in 5 years anyways lol.


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## cysmoker (Jun 5, 2019)

Here's a few pics of the start of the build.


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## cysmoker (Sep 5, 2019)

Making good progress on the smoker. About to the point of putting in my stack/exhaust. Can I use a 4x4 square tube instead of round stock? I think it will be easier to attach than round because I don't have a 4" hole saw.


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## daveomak (Sep 5, 2019)

4" square allows for about the same air flow as 4" round...  It should work fine...
4" round = 12.6 sq. in.
4" square = 16 sq. in..
The surface area of the square tube is greater than the surface area of the round tube and creates more friction..  That's why they are about equal in air flow... and the corners don't flow air well..


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## daveomak (Sep 5, 2019)

That air tank looks to be close to 1/4" material thickness..  the tag should tell...
I have one of those hooked to my air compressor for additional air reserve...
It will make a great smoker....


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## cysmoker (Sep 5, 2019)

daveomak said:


> That air tank looks to be close to 1/4" material thickness..  the tag should tell...
> I have one of those hooked to my air compressor for additional air reserve...
> It will make a great smoker....



Thanks for the response! It is 3/16", so a lot thicker than most air tanks out there I think. I know it's been chewing up my cuttings discs when I cut the door out. I'll try and get some pictures of the progress up here soon.


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## daveomak (Sep 5, 2019)

You've got a dandy CC there....


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## smokin peachey (Sep 5, 2019)

I wonder how this smoker must look by now.
Hopefully we will see some more pics soon.


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## cysmoker (Dec 10, 2019)

Well, life happens and this project got delayed a bit as I had too much other stuff going on. Finally got around to working on it again and ran into an issue with my door/hinges/banding around the door. I made the top cut of the door, then welded my "band" on (which I'm an idiot and welded it completely instead of tacking first), then welded on my hinges. Then I cut in the sides, welded on the bands, then made the final cut across the bottom. Great. My problem is that I didn't think about the clearance for the top band across the body of the tank for when the door swings open. I forced it open and got it to go. I tried putting a bevel on the lip of the body. Didn't help. I then took a pair of vice grips and tried to bend the lip. Can't get enough on it. So the door will not close now. 

If I cut the hinges back off and move them so they attach to the top band instead of the door it's self will that give me enough clearance? What other options do I have? I can cut the top band back off but I'd rather not. It's a 2" wide band x 3/16" thick. 1" of the band sits on the door, and the other 1" I designed to sit on the body as a seal.

Here's some pictures of what I'm talking about. Any input and criticism is accepted and welcome. This is my first  big metal working project so I'm still learning.


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## daveomak (Dec 10, 2019)

I'm not sure if I know what I'm looking at for sure.....
Is the door on the left ???   Is it hung up in the air due to poor fit  up ????
Is the strip down the middle of the picture, a door seal strip ???   Is it welded to the door or the CC body  ???
Here's a tip.....   NEVER fully weld ANYTHING on your smoker...  Skip welding works fine and helps to stop stuff from moving...  Even the RF plate...  skip weld it...  Even the FB...  skip weld it...


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## cysmoker (Dec 10, 2019)

daveomak said:


> I'm not sure if I know what I'm looking at for sure.....
> Is the door on the left ???   Is it hung up in the air due to poor fit  up ????
> Is the strip down the middle of the picture, a door seal strip ???   Is it welded to the door or the CC body  ???
> Here's a tip.....   NEVER fully weld ANYTHING on your smoker...  Skip welding works fine and helps to stop stuff from moving...  Even the RF plate...  skip weld it...  Even the FB...  skip weld it...



The door is on the right and the seal strip is welded to the door. It is hung up in the air and won't fully close. I'm trying to figure out what to do, short of taking the seal strip off to get it to close like it should. 

The seal strip is hanging up on the CC body.


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## cysmoker (Dec 10, 2019)

Maybe this will help show it a little better. This is the door fully open. You can see the seal strip on the door, the door goes flips down clockwise.  Basically the leading edge of the seal strip pretty much meets the edge of the cut on the top of the CC and stops there.

I'm wondering if I cut the hinges back off, rotate them to the left on the CC body, then weld the other side to the seal strip of the door if it will change the lift angle enough to give me a enough clearance. So basically moving the lift point on the door by about 3".


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## daveomak (Dec 11, 2019)

You welded the hinge in the wrong place.....
Looking at the picture in question, the center pivot of the hinge, MUST be to the left of the seal strip....  About 1/4"....   That allows for materials to not be in the way when opening and closing of the door....


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## daveomak (Dec 11, 2019)

With a grinder, cut the hinges lose from the smoker....  
Set the door in place....  centered in the hole.....
Tack the hinges in place and check the door travel....


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## cysmoker (Dec 11, 2019)

daveomak said:


> With a grinder, cut the hinges lose from the smoker....
> Set the door in place....  centered in the hole.....
> Tack the hinges in place and check the door travel....





daveomak said:


> You welded the hinge in the wrong place.....
> Looking at the picture in question, the center pivot of the hinge, MUST be to the left of the seal strip....  About 1/4"....   That allows for materials to not be in the way when opening and closing of the door....
> 
> 
> View attachment 423586



Now it makes sense. That will be on tonight's to-do list. Thank you sir!


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## daveomak (Dec 11, 2019)

MAKE SURE the hinge pins are in a line...


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## radioguy (Dec 11, 2019)

Hinges shouldn't be centered on door cut.  Offset them to the outside, this will make the hinge point lift the door and give clearance for the seal.

RG


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## cysmoker (Dec 12, 2019)

Thanks for all the help guys. I got it redone last night and now opens like it should. Starting to look like a smoker.


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## cysmoker (Apr 6, 2020)

The quarantine time has given me time to keep working on the smoker! Here is the fire box. 18x18 with 3/16" steel. I was originally going to use a 15 gallon air tank, but matting two  tanks with domed ends is a pain (i started at it), the 15 gallon was a little smaller than ideal, and then putting the dampers on the other end of a domed tank was going to be a real PITA as well, so decided I would just make the box .

I will be putting a slide damper on the lower right side (90* from the door side, which will put it in line with the opening into the CC), then I am going to put a pinwheel damper in the top center of the same side. Also, I am debating on tacking in some 1" C channel in an X pattern on the back side of the door to prevent warping. Can anyone tell me if this is necessary or is it over kill?


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## cysmoker (Apr 6, 2020)

Here is mounting the FB to the CC. Now I just need put in the RF plate, put in the chimney, build my cooking rack, build the fire basket for the FB, put some handles on and I should be about good to go. I'm also going to put a drain tube opposite the FB and run a channel in the center of the RF to drain the fat and grease. 

Also not shown, I originally made the frame too narrow, and with the big pneumatic wheels this thing was pretty top heavy. Like hit the wrong bump in the yard and it would tip over top heavy. So I cut the frame off and widened by 5".  I am glad I did. Much more stable now, and it lowered it by a couple inches so it's a little better fit and lowers the center of gravity a bit.


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## cysmoker (Apr 27, 2020)

More progress. Last thing I have to do it put the deflector in, put on a couple handles, cut in a spot for the grease drain tube coming of the center of the heat deflector, and build the food grate. It's getting close to finished finally.


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## daveomak (Apr 27, 2020)

Changing your exhaust mounting will go a long way to improving your smoker....


  ..


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## cysmoker (Apr 27, 2020)

Is that because of the 90 restricting air flow or whats the reason?


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## daveomak (Apr 27, 2020)

Yes...   the sharp 90 REALLY stops the air flow....   Air flow is extremely important in a smoker...   
Killing creosote with the extra oxygen....
AND, moving air from the FB to the CC, to reduce fuel consumption.....


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## cysmoker (Apr 29, 2020)

Reworked the exhaust. I had some rolled 4" wide 3/16" left over from patches I made to replace bungs in the top of the tank so I used that as the bottom of the plenum so hopefully this helps "roll" the air up in into the stack.


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## daveomak (Apr 29, 2020)

That looks very good....  Nice work.....


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## forktender (Apr 29, 2020)

radioguy said:


> Hinges shouldn't be centered on door cut.  Offset them to the outside, this will make the hinge point lift the door and give clearance for the seal.
> 
> RG
> View attachment 423617


I was going to recommend spacers under the tank hinges as well I'm not sure you would need them under the lid side of the hinge.

Lets see some more pictures 

 cysmoker
, it's looking really good so far.


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## cysmoker (Apr 29, 2020)

Here is another question I have. My heat deflector plate is done and I made it with 1/4" plate and ran C channel down the center of it for grease drainage. How well sealed does the plate need to be against the walls of the Cook Chamber? I was thinking of tacking on angle iron for the plate to sit on then I could pull the plate out for cleaning the bottom of the CC if needed, but If I do this it will leave a small gap the length of the CC on each side. Will this have a big effect on air flow?


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## daveomak (Apr 29, 2020)

Perfect...  You might drill holes in the angle and plate, when it's lined up, and drop a nail in the holes to keep it from moving....


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## rc4u (Apr 29, 2020)

wait wait you didnt mitre the corners on first pic..     loooks awsome


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## cysmoker (Apr 29, 2020)

rc4u said:


> wait wait you didnt mitre the corners on first pic..     loooks awsome


 
Mitre corners on what?


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## rc4u (Apr 29, 2020)

sorry post #4 .. i was a finish carpenter builder its just a joke like butting casing side to end..


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## cysmoker (Apr 29, 2020)

rc4u said:


> sorry post #4 .. i was a finish carpenter builder its just a joke like butting casing side to end..



LOL. I did mitre the banding around the door of the smoker at least....


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## cysmoker (May 5, 2020)

Deflector, grease drain, chimney redesign, and cooking grate slides and frame are done. Also found a wood stove damper at menards for $5 that I was able to steal the the handle off of to use for a handle on the intake slide. I'll cut the expanded metal tonight for the cooking grate and this thing will be pretty much finished. 

I'm going to have it blasted by a local dustless blaster to get the mill scale off and left over paint, then paint it with  hitemp spray paint. I talked to a local coating guy that said he would blast it and coat it with hitemp creakote that is used on exhaust, but that it would be $600. Pass on that.  The dustless blaster is charging $150 to blast it.  Worth it to me instead of chewing up flap discs and wire wheels and an entire saturday.


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## cysmoker (May 8, 2020)

Took the smoker and had it blasted. Now just need to weld on the hatchet I'm using as handle. Once the weather cooperates I'll paint. It is supposed to be cold all weekend so probably wont happen this weekend.


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## daveomak (May 8, 2020)

You may have to cut those hinges loose and reweld them with the door properly closed...  
Fix the door before you paint....


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## cysmoker (May 8, 2020)

daveomak said:


> You may have to cut those hinges loose and reweld them with the door properly closed...
> Fix the door before you paint....



I think what your seeing is that I put to much heat into the banding on either side of the door and it warped a little. I have latches/push stopper things that I welded on last night that push it in for a tight seal.


EDIT. Never mind. You were right Dave. Going out to cut and reweld it now.


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## daveomak (May 8, 2020)

Air leaks will kill your fire/temp control...  Clamp the door if it fits easily into the correct position...   You can tack weld it in place and weld...  Then cut the tacks after cooling...


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## daveomak (May 8, 2020)

If the gap persists, tack weld the door shut...   Build a fire and heat the begeezus out of the smoker to relax the steel...  Sooner or later it "should" relax the steel so it fits pretty good and minor sealing with gasket material will be necessary....  or remove the door and press it into the correct shape....


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## cysmoker (May 8, 2020)

Hinges cut and re welded. Thanks for talking me into taking another look at them Dave. I have to much time and work into it at this point to to end up unhappy because of that. I'm also going to run a gasket around the door too.


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## cysmoker (May 8, 2020)

The small gap you see between the banding and the tank is just the gap in the banding. The door now sits in flush with the tank if you really get down there and look.


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## daveomak (May 8, 2020)

Looks much better....  You may not need gasket material....   Some folks have used HIGH TEMP silicone sealant to seal up minor air leaks...   Gasket material that's too thick may open up a gap again....


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## daveomak (May 8, 2020)

One more thing....   When the smoker heats up, the door could twist or something like that and the body of the CC may interfere with the fit...   If that happens, a grinder is your friend...  
Cutting the door allows for the steel to try and seek it's memory...  Heating and cooling causes the steel to move...   After MANY heating and cooling cycles, it will settle in and provide you with many years of cooking pleasure ...  Low fuel usage and AWESOME Q....


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## daveomak (May 8, 2020)

OH....  one more adjustment to look at, if needed.....   Drill out the bolt holes on the hinges about 1/32" or so to allow the door to "move" and settle into place, if it's a bit tight....  All of these adjustments must be made while looking at the big picture...  Where is stuff in a bind...  where is it tight or loose...  etc...   ALWAYS use a lawn chair and a few iced down beer to contemplate your next move....   Patience is your friend when working on one of these as-built smokers...


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## cysmoker (May 10, 2020)

Smoker is finished. Had the initial fire yesterday to let it burn for a while. got it up to about 375 then closed my vents down and it settled in at about 250. the right side was about 15 degrees warmer than the left, but I think as I play with it and get used to it I'll be able to use that to my advantage. I plan on doing a pork belly this week and I think the fat in it will really help to season in the smoker.


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## cysmoker (Jun 1, 2020)

Need some help on fire management. I smoked some ribs on Friday for the first time in this smoker, and a 3lb corned beef brisket for good measure. Had a bit of bitterness  to them and too much smoke. Still edible, but not great. I used oak that I was told was cut a year ago, but I think it was a little fresher than that, so maybe the moisture in the wood played into some of the problem. 

I held temps in the cook chamber pretty well from 225-250. What I noticed is that I would come check on the fire every 35-45 min and find that the smoke had gone from thin blue to a slightly thicker smoker and that flames on the logs were gone to nonexistant. Once I jostled them around the a bit the flames would come right back and I would be in good shape for another 30 min or so. Exhaust and both intake vents wide open. This should be more than enough air intake. I have two hypothesis as to what going on. 

1. I think the expanded metal on the bottom of the fire basket is too large and allowing coals to fall through to the bottom of the fire box. Basically the basket just had logs in it and all the coals and ash are about 4" below.  So I'm wondering if the logs not sitting directly in the hot coals is allowing the fire to kind of snub out. 
        1.1 This is a pretty easy fix as I think I can just cut out another piece of expanded metal and run it perpendicular to the existing which will make the holes in the grate about 1/2 the size as they currently are to help keep the coals but allow the ash out. 

2. Not enough air intake. I have about 20 sq inches of air intake for a 60 gallon cook chamber with a 20 gallon fire box. I think this should be enough but maybe not. I have 4.5" of intake higher on the fire box directly across from the cook chamber opening, and 15" on the same side at/below the fire basket level. 

Long post but any input is appreciated.


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## daveomak (Jun 2, 2020)

Try cutting your splits smaller..    about 2" square type splits...   Watch them burn...  look for water oozing out of the splits to see if they are not dried enough...


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## cysmoker (Jun 2, 2020)

Thanks Dave. I will try that for my next cook. I didnt see or hear any water coming out during the last cook but I will watch again. My splits may be too large


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## cysmoker (Jun 25, 2020)

Closer to getting this smoker figured out. Ran it on Monday with Oak for about 8 hours for some beef ribs that turned out great. I used the smaller splits, and tended the fire a little more and the smoker ran right about 250-275 all day.


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## cysmoker (Jul 10, 2020)

Wasn't really happy with the pneumatic casters I used. The sidewalls of the tires had to much flex in them, so the smoker had a little bit of back and forth wobble to it that I didn't like. Plus, I was an idiot and welded the casters directly to the frame. 

So I cut the casters off and then made 4"x5.5" 1/4" plates to weld to the frame. Then I copied my template over and drilled 4 mounting holes. This way I can bolt my casters to the mounting plates, then if in the future a caster breaks or needs replaced I can just swap them out with out having to cut and reweld. 

I snagged some really nice 6" stainless casters out of the scrap bin at work.


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## cysmoker (Aug 6, 2020)

Has anyone applied Boiled linseed oil to their smoker over paint? My smoker is painted with high temp paint, but I'd like to cover it with linseed oil to help keep it protected. Not sure if it will bond over the top of paint and not directly to the metal.


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## daveomak (Aug 6, 2020)

Try it on a small area....


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## Dudeck’s Distributing (Jan 14, 2021)

cysmoker said:


> Well, life happens and this project got delayed a bit as I had too much other stuff going on. Finally got around to working on it again and ran into an issue with my door/hinges/banding around the door. I made the top cut of the door, then welded my "band" on (which I'm an idiot and welded it completely instead of tacking first), then welded on my hinges. Then I cut in the sides, welded on the bands, then made the final cut across the bottom. Great. My problem is that I didn't think about the clearance for the top band across the body of the tank for when the door swings open. I forced it open and got it to go. I tried putting a bevel on the lip of the body. Didn't help. I then took a pair of vice grips and tried to bend the lip. Can't get enough on it. So the door will not close now.
> 
> If I cut the hinges back off and move them so they attach to the top band instead of the door it's self will that give me enough clearance? What other options do I have? I can cut the top band back off but I'd rather not. It's a 2" wide band x 3/16" thick. 1" of the band sits on the door, and the other 1" I designed to sit on the body as a seal.
> 
> Here's some pictures of what I'm talking about. Any input and criticism is accepted and welcome. This is my first  big metal working project so I'm still learning.




looking to build a new smoker soonish (in the next 12 months lol) and I am glad I saw what you did with your hinges accidently.  I am building a long build note in my phone with point for items good and bad this is one of the ones I will avoid doing.


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## cysmoker (Jan 14, 2021)

Dudeck’s Distributing said:


> looking to build a new smoker soonish (in the next 12 months lol) and I am glad I saw what you did with your hinges accidently.  I am building a long build note in my phone with point for items good and bad this is one of the ones I will avoid doing.



yep best thing to do is learn from others mistakes. My biggest advice is don’t weld anything solid until you are positive it is where you and what you want. I learned that the hard way and it took a lot of extra work having to cut stuff back off or change stuff.

I’m on the look out for another tank to build another smoker. Going to try and find a 250 gallon and make a trailer smoker with it. I put in a new 18x24concrete patio to house my smokers so I have the room now for a bigger one. I basically plan to replicate this smoker just on a larger scale.


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## cysmoker (Jan 15, 2021)

Here's a few updated pictures as well, and one with a pecan smoked brisket.


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## JLeonard (Jan 15, 2021)

That thing turned out great. Looks good.
Jim


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