New 120 Gallon Smoker Build

Hi ya'll. My last build was a 100 gallon RF smoker back in December (http://www.bbq-brethren.com/forum/showthread.php?t=178267). It was the perfect size to compliment my 250 gallon trailer-mounted unit.

A friend I work with at the Pentagon liked my new one so much that we just drove 1000 miles to my Dad's in Arkansas a few weeks ago to build him one. This time we used a 120 gallon tank, and we built it as a straight-flow with tuning plates. My 100 gallon reverse-flow is OK, but I actually get more even temp distro with my 250 gallon straight-flow smoker (also with tuning plates).

This is my friend's first pit, so I'm teaching him how to use it. We did a small cook on July 4th (3 shoulders, a brisket flat and 6 racks of baby backs). We're cooking again starting tonight for 65 people at work tomorrow. This time we're doing 4 shoulders, 5 briskets and 20 racks of ribs - we'll probably do the ribs on his new smoker and everything else on my big one.

Anyway, below are some pictures.

Oh, BTW, my friend just joined the Brethren too...he's SmokeNShine.


Here's his new smoker, between my two:




Here's just the two 'small' ones:




Here's what we started with. We only used one of the two tanks, the firebox was made with 2' diameter pipe, 5/16th" thick:




After our trip to the scrap metal yard:




Here's SmokeNShine, plasma-cutting the door:




Door removed:




My Dad, plasma-cutting pipe for the firebox:




Fitting tank and firebox together (and showing off my homemade wagon wheels):




Starting to come together:




Smokestack in:




Tuning plates in and initially positioned based on gut feel:




Cooking racks in:




SmokeNShine, 'riding' his new toy:




SmokeNShine, sipping some 'shine, while we burn the gunk out of it. We got it up to about 500F during this burn:




After paint the next day:




Firebox:




Back in northern VA for our first cook on July 4th:




Ribs had just gone on, shoulders and brisket flat had been there a while (I don't put 'em in pans until a couple hours in):




I think we built SmokeNShine a pretty sweet smoker, but it's still not as bad ass as my big boy - here it was at a party for my daughter's soccer team about a month ago:

Doog said:

Where do you get your tanks at for your builds?

Thanks

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I got these at Beiler's Pneumatics in Lancaster County PA. Nice Amish guy that refurbs decertified propane tanks for air use. He had quite a few of these 120 gallon tanks. He sells them for close to $300 when he's done with them, but I got these for $132 each before he did anything with them.

http://www.lancodirectory.com/store_fronts/beilerspneumatics.html

va_connoisseur said:

Nice work. Are the tuning plates movable?

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Yes, they are movable. When you get them where you want them, they clamp down with a bolt on each side. They can also be removed for occasional deep cleaning.

All fired up said:

looks great but it sure dont look like the intake is big enough

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It probably isn't. To get it real nice and hot (since I'm teaching him to cook hot and fast), we can leave the door latch a little loose to pull in more air. Once it's up to temp, it seems to maintain ok through that damper.

He's planning to put a temp controller on it like my big one has. We'll cut a separate hole to feed the 50 cfm fan through - that'll give him plenty of air.

BLOWIN SMOKE 87 said:

Very nice! Do you know the dem of the smoker? Looks like about 24x60..

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The cooking chamber is 24"x65" (at it's widest point). The door opening is 50" wide, and the two slide out racks are a little over 49" wide. The firebox is 24" diameter x 22" long.

The 100 gallon tank on the one I built in December is the same diameter, but about 6" shorter.

Smoke Dawg said:

You do nice work

Cutting and welding in shorts?

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Thanks on the nice work statement. My Dad is a retired welder, so I try to learn as much as I can from him each time we build one together.

As far as the shorts go, it was July in Arkansas, so we were willing to take our chance with the welders, plasma & torch, to try to avoid heat stroke. Maybe not the brightest move, but we made it through without injury.

Trailer Trash said:

Wow!!! Awesome!

As far as your welding apparel, I wear sandals when welding and have some damned ugly feet to show for it! Tell us more about the "tuning plates". How do you estimate where they belong? How long each? What do you observe for changing positions etc. and make adjustments accordingly?

Great job!

Click to expand...

The plates are 1' x ~21". Once I had the firebox mounted to the cooking chamber, we welded 2 ~50' lengths of angle iron (1/8x1.25x1.25) horizontally, inside the cooking chamber along the front and back wall, just above the top of the opening from the firebox. We held the corner of the angle against the tank (so that one 'leg' of the angle is vertical and the other is horizontal), then welded from the top in the gap between the vertical leg of the angle and the tank wall. That gave us a flat ledge to set the ends of the plates on. I measured the distance between the pieces of angle (front to back in the smoker) and cut the plates to fit (~21"). The width (left to right) of 12" is just a number I picked. I knew I wanted about 4 plates, and an even foot seemed to work well.

I initially positioned the plates based on experience with the tuning plates in my 250 gallon smoker. For example, I knew I wanted the first one right against the firebox, the gap between the first and second plates to be about 1/2", the gap between the second and third plates to be about 2", and the gap between the third and fourth to be about 3-4". Once I had the angle in place, we welded large nuts to the top edge of the angle near the midpoint of each plate. We then ran bolts through the nuts to clamp down on the plates to keep then from moving.

With the smoker up to temp and fairly steady, I just check the temps on each end of the smoker. If they are consistently off, I tweak the placement of the plates. If I have meat on the smoker, I don't judge by the door mounted thermometers, since large slabs of cold meat can shield a thermometer and make it read lower. I have used oven thermometers on each end of the rack, as well as remote-reading thermometers.

I had a different system on my big smoker when I built it several years ago, and I sometimes had a 20-30F temp gradient across the smoker. Now with the tuning plates, I can keep it the same temp all the way across (or even hotter on the stack end).

I hope this helps. If you want to see additional pictures, let me know.