Smoker build

[KHoes203]

Have always wanted to build one an finally got around to working on it. Got the 250 gallon tank cut last weekend and got the fire box built today and now just waiting to finish up the trailer and put the fire box and tank on it. This is my first one to build so any pointer would be appreciated.

[paulgmckavett]

Looking good so far

[Tyhuck]

Cant wait to see it come together

[KHoes203]

Got the fire box all welded up today and the door vents cut and now I have to wait to get the bearings for the hubs that the guy failed to put in the package deal. The fire box is 1/4 inch and 30" wide, 20" tall, and 24" long. Do yall think that it will be big enought for a 30" in diameter tank and is 47" long?

[jgard2522]

Good luck with it buddy

[Welderman]

Originally Posted by KHoes203

Got the fire box all welded up today and the door vents cut and now I have to wait to get the bearings for the hubs that the guy failed to put in the package deal. The fire box is 1/4 inch and 30" wide, 20" tall, and 24" long. Do yall think that it will be big enought for a 30" in diameter tank and is 47" long?

That should be big enough, just be careful, without a heat shield in the smoker you will have a hot spot on the firebox end. I have built several that had larger smokers than yours with a firebox that size and they did real well.

[KHoes203]

I have a damper will that help the hot spots any?? Or heat shield as in I need to run a plate a good ways down?

[Welderman]

Most heat shields run the entire length of the cooking area with a damper built in to the heat shield on the end opposite the fire box. This puts your smoke stack on same end as your firebox to draw the smoke and heat back across the cooking area. A damper alone at the firebox will help some, but it still gives a hot spot next to the firebox. The heat shield means more work in building and $$$ but is a nice feature to have if you want an even heat distribution in the cooking area.

[cablesplicer]

looking good

[txfireguy2003]

What welderman is referring to is called a reverse flow smoker by the BBQ gurus. Check out www.thesmokering.com for some ideas. There is also a link in there is you search for pit building ratios, that will take you to a calculator which will tell you all the sizes you need for firebox, air inlets, vents, exhaust stacks, etc. General rule of thumb is, the firebox should be approximately 1/3 the VOLUME of the main cooking chamber's volume. Based on those dimensions, the calculator will tell you how big of air intake you need for your firebox, how big of an opening from the firebox to the main cooking chamber, and how much exhause volume you need. Basically, on a well built pit, the exhaust controls everything when it's running right. You shouldn't need to restrict intake air very much, and you shouldn't need to gate down the flow of heat/smoke from the firebox into the cooking chamber. Assuming a 4" diameter stack, you can control the temp that the pit wants to run at by changing the length of the stack, longer/taller stacks draw more air (creat more suction), effectively pulling more air through the intake and making things hotter. It's counterintuitive, but closing your exhaust down will actually COOL the pit down as the fire can't get the smoke out, there is no room for fresh air to come in, effectively smothering the fire....this is okay to a point, but not ideal. You want your fire to burn its fuel (the wood) completely and cleanly. On a sunny day, you should just barely be able to see any smoke coming out the stacks, it should be thin and have a blue tint to it. I built one back in September that is made from a 250 gallon tank, a 100 gallon tank and three 8" pipes. My tanks run parallel to each other, with the 100 gallon tank used as the firebox, and slightly lower than the bigger tank, which is the cooking chamber. The three pipes run from the firebox tank to the smoker tank and carry heat and smoke to the meat. Once I get it up and running and all the metal heated up, the temperature across the smoker tank is even across the entire tank with less than 5 degrees variance, and right at 225 degrees. That's with the air intakes completely open, no dampers between firebox and smoker, and the exhaust completely open. This is wonderful for cooking a lot of one type of meat that all needs to cook at the same temp, like say 10 briskets, but if I'm cooking a couple briskets, a couple racks of ribs, and 20 pounds of chicken, all which need different cook temps, it's a problem. To solve this, I open one stack completely and close one stack down somewhat. This causes more of the smoke and heat to be pulled toward the open stack, causing that end of the pit to be hotter.

Sorry for the novel here, if you can't tell, I'm kinda into BBQ and pit building. If I can give you one word of advise, it would be to extend you exhaust stack down into the tank at least to the level of the lowest cooking grate. On my latest pit, they actually extend about 6" below the level of the grate. So, your 250 gallon tank probably has a 30" diameter, and I'm assuming you are placing your cooking rack in the center so you can get the most rack space, so it's 15" from the top....your exhaust stack should extend down INTO the tank at least 15". For that size tank, if you're using 4" pipe for exhaust, you'll need roughly 4-5 feet of stack length (just an estimate based on my pit which is slightly bigger, look up the calculator to be sure), so 60" total, 15" inside tank, 45" outside tank....that's pretty tall for me, so I would normally cut it in half and do two stacks right next to each other. So, you're at 15" inside the tank and 15" outside X2 stacks....that's puts the top of your stacks 15" above the top of your tank, which should be about the same level of your open doors, so easy to reach a baffle on top of the stacks. If you just cut a hole in the top of the tank and weld a pipe on top, the smoke comes out of the firebox, goes immediately to the top of the tank, runs down to the exhaust and straight out. If you extend the exhaust down into the tank, the smoke rises to the top, but has to "bank down" to the bottom of the stack before it can exit, causing your meat to be surrounded by smoke on all sides. When I cook briskets on my pit, it's nothing for me to get 1/2" thick smoke rings in the meat.

If you have any questions, PM me, I'll be glad to help any way I can.

[paintman]

my advice would be dont go small on your smoke stack,my pit ha a 9 inch dia smoke stack which is way big but that pit will draft anywhere,and you can always damper it down,great job so far and keep up the pics

[Trap-Daddy]

looking good, you have a great rig your working with too

[KHoes203]

Thanks texasfireguy that's a lot of pod helpful info. I am going to work on it a bunch this weekend and finally mount it all up to the trailer and get the axel mounted and the tank and fire box put together.

Question 1: I have a 6 inch stack will this be to big? I also have some 4 inch pipe so easy change.

Question 2: my dad has gotten concerned about the shape of my damper. He said the he will have a tendency to go out the edges insted of the middle. Will the plate I am going to put on the bottom help solve this??

[paintman]

definatly go with the 6 inch stack

[marknmatagorda]

What size welder are you using? Interested in getting one.

[KHoes203]

It's a miller 211 it runs on 110 and 220 it's well worth the $$$ because you can run on either and will weld more than I need!!

[KHoes203]

Got a bunch done this weekend finally coming along! Got it mounted on the trailer had to wait on the hubs to get in to mount the axel. Got it all balanced out and going to cut the door and stuff out next weekend. Got a new sweet tool to help! Will never use a torch again!

[mike1104]

looks very cool

[KMccleskey]

That's ******!!!

[txfireguy2003]

Sorry I haven't been back sooner. In answer to your questions:

1) 6" stack will be fine, just don't go too long, you don't want too much draft, that will cause your fire to burn too hot, and your tank will get too hot to cook low and slow. It will also pull lots of air into the firebox, causing your wood to burn faster, meaning you'll need more wood to do the same cook and you'll have to pay closer attention to your firebox fuel load.

2) I wouldn't worry about the damper too much, you're going to have heat and smoke coming through that vent one way or another. You're always going to have a hot spot closest to the fire box unless you put in tuning plates, and I don't see that in your design. Could be added pretty easy probably, it just doesn't look like you have them designed in.

One thing I saw that I think you need to consider is weight distribution on that trailer. You want 60% of the total weight in front of the axel for proper distribution. I understand you'll probably have a wood rack on the front, but what happens when you tow it to a cook, burn up all your wood, and then have to drag it back unbalanced. And improperly balanced trailer will steer your truck more than the truck steers the trailer.

[KHoes203]

Thanks for the info man I really do appreciate it. I am going to make the plates next weekend to tune it. I also took the pic before we balanced it and the shackles are just tacked on not on the proper spot. In your 1st post were you saying that the stack needs to be inset into the tank some? Sorry I guess I can't picture what you are saying there. Thanks again man!

[HoytEast7272]

Nice!

[txfireguy2003]

Originally Posted by KHoes203

Thanks for the info man I really do appreciate it. I am going to make the plates next weekend to tune it. I also took the pic before we balanced it and the shackles are just tacked on not on the proper spot. In your 1st post were you saying that the stack needs to be inset into the tank some? Sorry I guess I can't picture what you are saying there. Thanks again man!

Basically, instead of welding the stack to the top of the tank, cut a hole big enough for the stack to slide down INTO the tank. If you have a 30" pipe for the stack, drop it down into the tank so that the bottom of the pipe is at least as low as the bottom meat rack. You'd end up with about 15" inside the tank and 15" outside the tank. OR, if you're coming out of the end of the tank and turning up, come out of the center instead of up high. You want the smoke to build up in the top of the tank and kind of swirl there instead of just going up to the top and out of the tank without touching your meat. I'll see if I can draw up a quick and dirty diagram in a second.

[txfireguy2003]

Here you go:

[dgh]

i sure like this thread....keep it coming

[KHoes203]

Got it! Thanks man! I really do appreciate it! I was thinking going out the end and have to inset the pipe from there which did not make much sense to me.

[KHoes203]

Did not get a lot done this weekend had a bunch of friends out and the beer was cold so was not to productive other than the door cut out and the rack built.

[bt2143]

it's coming along

[czechaholic]

Looking good

[czechaholic]

Here is a pic of mine......ol puffer Pete!!

[markandles]

looks good

[KHoes203]

FINALLY got the wheels and got it home so that I can work on it more! I will update with pics on Thursday but here is what it looks like!

[KHoes203]

Sweet set up but I think that would be a little much for my needs... I am maybe goign to cook for a max of 25 people.....

[Todd]

got to love a deflector plat

[KHoes203]

I finally got to work on it some more today and this is what I got. Got the smoke stack (which is going to get cut some) got a propane tank holder and cooker on the front.

[Pedernal]

Nice

[txfireguy2003]

Nice, stack looks good bro. Sure wish I could cut miters on pipe like that, I always end up crooked or wrong angle or something else wrong. I just end up cutting a hole in the top and sliding the pipe down from there, or using square tubing like I did on my last pit.

[KHoes203]

^^thanks man! It was kind of a pain but with some rigging and some luck I was able to fit it in the chop saw. Thanks again for the help. Do you think having the top of the opening of the stack being an inch below the grate is low enough? Do you have an idea about how tall the stack should be? It's 4 feet now from the 90.

[mvill]

Nice going coming along pretty good

[KHoes203]

Well worked on it all day today and did not get a whole bunch other than welding a bunch of stuff up. Here is the damper control that I just Have tacked on and need to drill the holes in it. You can kind of see the idea...

[bsills]

Lookin good

[txfireguy2003]

It keeps getting better and better man. To answer your questions, YES, 1" below the grates will be plenty far down. The only goal is to get the smoke to fill up all the way around the meat before it can exit, anything below grate level will serve that purpose. As far as the stack length goes, I don't know all the exact dimensions on your pit, so I can't run the numbers in the caluclator, but just by looking at it with my calibrated eyeball, I'd say 4' up is plenty. Once you get it complete, open all the dampers and valves and start a fire. Run it wide open and see where it likes to run, then try to gate it down. I like to be able to make them run from a little less than 200 degrees all the way up to 400 degrees, never cook anything any hotter than that, so that's all I need. If you can't make it run at 200 degrees, try cutting your stack a bit shorter, if it won't run up to at least 300-350, weld another piece of pipe on to make it longer. I've said this before, but I'm going to say it again, I control my pits as much as possible with the EXHAUST. I want the fire to have as much oxygen as it can consume so it doesn't smolder but burns clean. Sometimes that means I have to gate my exhausts down to run it cooler, and sometimes it means I have to crack the doors open until the fire burns down some, but I try to NEVER shut the air intakes. I build small fires to start off with, then gradually build them bigger until I have the temperature I want.

[KHoes203]

Thanks man I really appreciate ALL the help!!! I hope it work ls alright! And I really can't wait to get cooking!

[donfish84]

Looks really good kh!!

[ATControlFreak]

Great work!

[shootsmall]

Great work and awesome thread. Some cool ideas on yalls smokers.

[KHoes203]

Worked on it again today and finally got the smoker door on, stack damper, and hinges built and on. The door with the horse shoe is the fire box door and the air damper system on it 1st one is closed, 2nd is open.

[Reaper]

awesome build!

[ibowtech]

Originally Posted by Todd

got to love a deflector plat

Now that's serious stuff there!!

[KHoes203]

The gates got done today.