250 gallon cross flow smoker build thread (2 Viewers)

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workingdog

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Okay, I had no idea where to put this. It has no motor, but it's going to have wheels. So, because it cooks, so I'm putting it here and someone can move it.

My son and I picked up this 250 gallon tank on Mount St Helena (northern Napa valley). The mountain top lot had sold, the buyers didn't want the tank, it was free to anyone that could get it. And Luckily, we were able to.

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Here's what I'm planning. I attached a pdf, not sure how that works.

So, first step was to getting the fittings off the top and the tank safe to work with, done that.
Now, it's in the garage and the laser is out and I'm doing layout, - vertical center line and horizontal center line, doors, collector - and start cutting.

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Attachments

  • smoker drawing pdf.pdf
    33.2 KB · Views: 39
How cool is that!! Huge BBQ smoker here subscribing for sure!
 
Okay, got the propane tank into where I could work on it. Got the collector hole cut and started on cutting out the doors. 1 35" door cut = 1 4 1/2" cut off disc. The first went fine, but you can see on the second how the tank relieved stress and isn't quite right. I'm curious what it will take to make all fit once the doors are finally cut.

Tomorrow I'll cut most of the vertical cuts, leaving a 1/4" near the bottom and top so that I can put strap on the top and bottom, attach the hinges lightly, before cutting all the through. We'll see how much that door springs free at that point.


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So, doors are cut out, hinges are tacked in place, I've started the strap/edging. The tanks and doors continued to move as I cut the last of it holding. I'm going to use fireproof strip around the edge so hopefully I can absorb some of the movement. but I'm definite going to have to put my 20 ton air powered jack in the tank to raise the top edge of both opening.

The inside of the thing is nasty and smells like propane. the smell won't go away. So, despite the rain, I'm going to get it outside under and eave and start a fire today with the doors propped open and burn all that crap out. Then I'm going to get the torch out and bend the vertical strap into place and then take the old feet we cut off and massage them to make stops for the doors. If the doors get away from me, they will make one hell of a bang. And, I'm going to figure out something fun to make a counter weight out of - like a brake rotor or an old clutch or something.

And then it's on to building grate slides and grates until the plasma table gets here and I can cut everything for the collector and the firebox. The 1/4" stuff at least, the 3/8" stuff I'll have to have my local water jet cut.

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Okay, the vertical straps are installed. What a PITA. I don't the oxy acetylene torch often enough, and every time I drag it out I have to learn how to use it again. I was hoping that if I heated the strap enough, it would just bend into place. But ... that didn't really work. I had to used section of conduit under the strap to get it to bend enough and even then, the ends were impossible and the tack weld at the bottom would give. In the end, just sticking in my vice turned out to the easiest option. Next time, I'm going to pre-bend them prior to installing. the doors close okay but not great. We'll see what it takes to get a seal.

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Stops are in. The old feet have a new life. Not sure if the doors even open the same amount because if you open both doors right now, the tank just spins violently on the stand. Ask me how I know.

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I have a lot of oak on the property that's come down in the last couple of years. I'm going to plow through that. I know there's walnut around as well. And plenty of apple and other fruit trees if I look hard enough.
 
Thats gonna cook quite a bit of meat! I'm big fan of TEL-TRU BBQ thermometers if that bridge hasn't been crossed yet. Very accurate!
 
Yes, you don't think of 250 gallons as being a big tank, but it has more then enough capacity for the backyard. This one is going to go to my son in Montana (if it's no too bad) and I'm going to make myself a smaller, reverse flow for my house here.
 
First, it never occurred to me to think about the rollers on the fixture when I started the fire. Now I need new rollers. but at least the fire got rid of the smell and the gunk in side.

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So, trying to take the warp out of the tank at the doors.

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So, you tube split this into two videos. In one you an see how far I'm over bending, and in the other you can see the release right back to where it was. I'm scared to push any farther. But maybe that's what it takes. It also seems like a really big area to heat up. I could just put an extra layer of fireproof tape in there and call it good ..... ?



 
I'd push that a little more to see if you can straighten it. Also, maybe weld some reinforcement in that area possibly, something to keep it from flexing too much later.


It's going to flex a whole heckuva lot more once you bring the entire smoler up to temperature.

It's interesting that there is that much tension on the steel already.
 
What is your son in Montana going to use for fuel in that?

Oak is nearly impossible to find up here. There is some apple, but I haven't found anything good to use in an offset up here.

There is a local steakhouse that cooks directly over tamarack coals.
 
I have no idea what fuel he's going to use, but he's resource full. But there are a lot of barbeque joints that must be using something. Anyway, they'll probably just fill it with ice and beer for parties.

This was pressure that always been in the tank since it was formed. You can see how the 4" strip in the middle not cut out for doors is holding that part round. I found it interesting that the doors stayed pretty straight and the tank moved. I had it pretty hot yesterday with the fire in it. I think hotter than it will ever get used as a smoker. I guess I could bed it up and put a gusset in it to hold it.
 
So, made and installed the cooking grates today. At first I wanted them to be able to slide in and out, but when I located them, it just put the grates too high in the cooking space.

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If I really wanted to have slide out grates, I should have cut the door openings 2" lower. Live and learn.

So, I set them flush with the door opening and I'll add some handles and make them so the can lift out.

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Seems like they will work just fine.
 
What are the overall dimensions of the tank?


I have a 250 gallon air tank that I'm going to make a smoker out of, but I'm only going with a single door on it. I'm guessing the diameter of the tank I have is a tad larger.

I'll be back with measurements.
 
This is about 25" in diameter, so relatively narrow. I think it's about 80" long from seam to seam, plus the ends. The doors are each 35" wide.
 
So, made and installed the cooking grates today. At first I wanted them to be able to slide in and out, but when I located them, it just put the grates too high in the cooking space.

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If I really wanted to have slide out grates, I should have cut the door openings 2" lower. Live and learn.

So, I set them flush with the door opening and I'll add some handles and make them so the can lift out.

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Seems like they will work just fine.

Can you roll the tank forward so the edge of your door cut out is 2" lower?
It would make the top of the door 2" lower too, but that might not matter?
You'd have to change your door stops.

In regards to the warping, I reckon get a HOT fire going in it, and heat it above your cooking temperature range, give it time to really heat soak all over.
Check temperature of the steel with an infrared heat gun.

See what you're left with then.
Would suck to put effort into straightening, only to have stuff continue to warp once it's well heat soaked.

Edit: I see you already fired it. Looking at the amount of paint left on it, I don't reckon you went hot enough, or long enough
 
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Got handles made, cut the ends on my new plasma table - there's a thread about it over in the tools forum.

Now that the plasma table is up and working, there should be much progress.

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