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

[Bucksaw]

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]

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.