Tucker's First Reverse Flow Smoker Build

[MattTucker]

Since I am a newbie to the site, I figured I would chronicle my smoker build on the site, for other newbs to learn from my mistakes. This is my first smoker build, and currently I do not have a set of plans and am loosely planning this from calculators and reading posts on the internet......drawings are merely suggestions anyway...right?

In the interest of full disclosure, I work in the office of a structural steel fab shop, so access to steel or the tools of the trades generally isn't an issue (including an 8ft x 20ft high def plasma table) and this smoker build has been on my mind for quite some time.

My initial vision for the smoker was to make a large reverse flow smoker for my patio, based loosely on the Lang 48" Deluxe Patio Smoker, but after calculating the weight of the smoker and my want for possibly using it for a competition or two, or to take to a buddy's house for a party or what not, and several conversations with guys at work, I am opting to put axles under it and make it a trailer smoker.


The Cook Chamber (PL 5/16 x 24" x 48")

I had the cook chamber rolled by one of our suppliers. It was a toss-up between 5/16" plate or 3/8" plate. I ended up choosing 5/16" plate rolled for a 180 degrees @ 24" diameter for tops and bottoms and a 12" flat section between to create an oval. The inside will measure 24" deep (from front to back), 36" tall (from top to bottom), and 48" long (from left to right).

If I used Feldon's BBQ Pit Builder Calculator correctly, my cook chamber size is approximately 35,527.68 cubic inches and would require a minimum firebox size of 11,842.56 cubic inches.


The Fire Box (PL 3/8 x 24" x 24" x 24")

I had the firebox bent out of 3/8" plate. The inside will measure 24" deep (from front to back), 24" tall (from top to bottom), and 24" long (from left to right).

Knowing that I need a minimum of 11,842.56 cubic inches for the firebox, I went a little larger with the firebox above as it checks out to approximately 13,824 cubic inches.

In the coming two weeks I hope to do the following:
1. Weld flat plate to close the cook chamber (we plan on cutting the door out of the rolled side, to ensure that that door has good fit, but will need to do as much welding as possible prior to cutting out this door to avoid any warping from the welding.
2. Determine needed firebox opening size
3. Determine the thickness of the baffle plate (I am leaning toward 5/16" material)
4. Determine the size of opening needed at the end of the baffle plate for consistent heat and smoke draw.
5. Determine the location, size, and length of the exhaust stack.
6. Determine how to add a small vertical warmer / smoker above the firebox

This is going to be an interesting process and I look forward to sharing it. I am open to suggestions for any of the tasks listed above.

--Matt Tucker

[TuscaloosaQ]

Man that is an awesome start!!!!!!!

[Gizmo]

Thanks for this thread - looking forward to this build for sure…

[The Czar]

Sweet....looks like your going to very happy with your build

Sent from my iPhone using Forum Runner

[Clover Ridge Smokers]

I really like where you are going with this. Be sure to post lots of pics of your build.

[Smokeone]

Awesome!
A high def plasma table...........I am not worthy.

[MattTucker]

A high def plasma table...........I am not worthy.

It is a pretty efficient tool to say the least. Our table is an 8ft x 20ft water table with a ThermalDynamics UltraCut 300 plasma unit on it. We get great results up to 1-1/4" thick mild steel with it. The table also has two oxy torches on it for when we go 1-1/2 to 3" thick on some base plates or what not. Fairly costly as well.

[MattTucker]

After searching the forum for a while this afternoon along with the interwebs, I am still left with one major question that I don't have a concrete answer for.

1. How large of an opening do I need to go from the firebox (PL 3/8 x 24" x 24" x 24" & 13,824 cubic inches) to the cook chamber (PL 5/16 x 24" x 36" x 48" Rolled Per Above & 35,527 cubic inches)?
*The answer I get from Feldon's BBQ Pit Builder is 16.78" Diameter for a half moon opening as the recommended firebox to cook chamber opening area is 110.59 square inches. If I read this correctly, that would mean that my opening needs to be approximately 8-1/2" tall from the bottom of my cook chamber...does that seem correct?
*Is there a problem with having too large of an opening?
*Would it be beneficial to put some sort of adjustable opening from the firebox to the cook chamber (as sort of a heat management tool)?

Would anyone care to shine some light on this for me?

[Gizmo]

The pit calc on this forum will tell you….

It's the last item listed under the welding and fabrication department

[MattTucker]

Sorry, I didn't even know that calculator was here until your post. No disrespect meant. Will give it a go when I get back to the computer and off the tablet. Looks cool though.

[Rodcrafter]

I'm looking forward to watching this one too! This is going to be a heavy rascal, just my sort of cooker.

[MattTucker]

Thanks to some help from one of my uncles and some guys in the shop, the smoker build is starting to take shape.

The cook chamber upright with the firebox endplate attached

We left a 1" lip on the air inlet to keep back any grease that may run down towards the firebox.

The cook chamber to fire box endplate

Another look at the firebox end plate.

Reverse flow baffle plate & drains

The baffle plate is 5/16" thick and slightly pitched to drain to the 1-1/2" drain. It will be seal welded to hold liquid, should it be used. The drain at the bottom of the cooker is simply another clean-out.

The firebox with air inlet's cut in it

The firebox is starting to take shape with some 3" diameter air inlets being cut in it. In addition, there will be two holes cut in the top to allow smoke / heat into the rib box to be built. It will be sealed with 3/8" plate.

All in all, it is starting to take shape. I did underestimate just how heavy this beast is going to be. It is going to be a monster -- the firebox is heavy enough that it can't be rolled by hand (hence the crane jaws in one of the pics).

I ordered the axle yesterday. I am going with a single axle 3500lb capacity, it will be 42" hub face to hub face and is being shipped with open spring centers so we can locate the springs as needed.

[The Czar]

[MattTucker]

Here is some cad drawings of the side elevation of the cook chamber. I will work on the other elevations as the build progresses.

End Plate With Cut-Out For Firebox

Using the PlanetCalc calculator to calculate the area of a circle segment, this cut-out should give me approximately 118 square inches, of which I need approximately 118 square inches, hope i should not have oversized it?

End Plate Without Firebox

This cook chamber will measure approximately 4' - 0" long when complete.

More plans to follow, as the build progresses.

[MattTucker]

What is the most preferred method of probe ports for meat thermometers? I want something that can be completely sealed off when not in use, and is fairly air tight after the wire is ran through. What is everyone using?

Also, was thinking of putting two thermometers on the smoke chamber about 1ft in from each end (leaving them at 2ft on center). Is that too much.....just do one gauge in the middle of a 4ft chamber?

[Gizmo]

I think you'll like 2 gauges on that length of CC.

A piece of fire rope stuck to a small piece of sheet metal to cover a hole for the probe wire to go through works really well.
I've always just put 2 screws through the sheet metal cover to squeeze it down and mount it.

Instead of the screws I've always thought about using the clip off an old clipboard so I don't have to scare up a screwdriver every time I put the wire through. The fire rope just surrounds the wire when closed so you don't damage it.

[Clover Ridge Smokers]

Great looking build

[Rodcrafter]

I would say that you may want to know what the temp is on each rack level. Considering the size of your CC it may take a while to figure that out just learning the cooker. I use a 1/4" hole any where near the rack, put both of the leads from my Maverick ET-732 temp tester in it, and don't get that concerned about the fraction of an inch left to seal in that hole. When I'm not using the hole, I put a 1/4" bolt in it to seal it. It works for me.

jm2cw

[MattTucker]

We are making forward progress. The cook chamber is all welded up, the exhaust stack is in, and the firebox is almost done. Still need to cut the door, make a door for the firebox, build the rib box / warmer on top of the fire box, and mount it to the axles (which have not delivered yet), then add all the fits and finishes and paint it.

Cook Chamber All Welded Up With Exhaust Installed

The cook chamber is all welded up and ready for the door to be cut out. We used 6" std pipe for the exhaust pipe and went to a height of 23" based on the calculators we used. It is starting to come along.

The 500lb Fire Box

The fire box will weight almost as much as the cook chamber when it is complete, thanks to the 3/8" thick plate it was made out of. We added holes on top that will be controllable and have 3/8" cover on it to regulate heat into the warmer box / rib box that we will build on top of it.

The Fire Basket

We were not really sure on the size of the fire basket, so we went with one that is approximately 12" deep. If that is not deep enough we will modify it and make it deeper.

So all in all it is starting to come together. I did order some spring handles and thermometers from BBQ Bonaza at KCK and got them ridiculously quick. So hopefully will have more photos and a drawing or two soon. I have calculate the build to come in around 1400lbs when complete, so it will be a heavy pit for sure.

--tucker

[The Czar]

Holy guacamole !!!!!!!!!!!

Sent from my iPhone using Forum Runner

[Smokeone]

Looking good Matt! I can't wait for the samples, I'm just down the road you know.

[MattTucker]

Holy guacamole !!!!!!!!!!!

I guess this is what happens when a structural steel guy decides to build a smoker in his shop.....1200lbs later.

I ran in to a little issue with my axle and had to cancel the order. I was having one manufactured and was told 1 to 2 weeks, and when i called to check on it, was told it would not be ready until 9/6. So now i am going to pick up an axle local and we are going to cut it down here. Was hoping to have it done by labor day weekend, but don't think i will make it.

[MattTucker]

The smoker build is coming along, surely but slowly. I ended up at NortherTool on Monday night and dropped close to $700 for the trailer parts (axle, hubs, wheels/tires, trailer coupler, trailer jack, light kit, leaf springs and attachment kit). But it will sure be nice when it is done.

The Firebox is Finally Attached

The firebox has been attached and essentially finished. There are three 3" inlet holes on each side of the firebox, along with a slider to close them off as needed.

Another Look At The Firebox Attached

Just another look at the smoker with the door cut out. Damn this thing is heavy.

The trailer is on the table now.

[Rodcrafter]

[Clover Ridge Smokers]