Fabrication Question

[Beerwolf]

I am in the process of building my first smoker. I am using a 100# bottle for the smoke box ( horizontal) and am planning on mounting a 7 gallon bottle in the middle of smoke box with a feeder tube from under. I am feeling that this will be the best solution to reducing any cold spots in the smoke box, which leads me to my next question:

In the interest of maintaining balanced heat, I am contemplating using 2 chimneys, one at each end, around 3 inches in diameter. I am thinking a smoker this size would do well with a 4" stack and If I am wrong, Id rather err on the large side and be able to dampen rather than have to make a bigger hole. I will also put 2-3" air flow tubes at bottom of the fire box, at opposite ends of the 7 gallon tank.

I am new to building one of these things and really welcome any comments as to if I am on the right track or not..

 

[parrothead]

Sounds like a pretty solid plan to me, as long as you know what you are doing when cutting the tanks. I wouldn't have a clue to that, but the design sounds feasible.

 

[Captain Caveman]

Make sure you have a way to level it. I have a set-up kind of like that on my BBQ trailer but I have 1 firebox and 2 seperate smoke chambers (each with their own exhaust). If mine isn't level 1 side runs up to 100* hotter than the other.

 

[bbqbull]

Sounds like a pretty solid plan to me, as long as you know what you are doing when cutting the tanks. I wouldn't have a clue to that, but the design sounds feasible.

I know that breaking up chunks of dry ice and placing it inside the tank and letting it vaporize should make it safe to cut. Passing along advice that I havent tested......nor would I even consider it.

A very good friend of mine who builds world class bbq pits also told me that old or used propane tanks.........that the different blends of gasses permeate the steel and will emit weird tastes to the food as its being cooked.

That IMHO.........may or may not make folks ill.

Just passing along what I was told.

 

[Bigmista]

I'm pretty sure that I have no idea what this thread is about.

 

[Jaberwabee]

I'm pretty sure that I have no idea what this thread is about.

You sir are a genius.

 

[Puppyboy]

I'm pretty sure that I have no idea what this thread is about.

You are not alone.

 

[tony76248]

He is talking about a 100# and 7 gallon with 2-3" chimneys and a 4" stack with 2-3" air flow tubes.

Ok I would recommend.......

We are just being funny. Tell us what you want and we will give advice o you can achieve your smoker based on what we have experience with.

Sounds like you want an offset smoker. with a smoking chamber and a firebox. Nix the twin tubes unless you are going for a 6 foot long smoking chamber.

The size of your firebox will determine how big a fire you can build hence how hot a fire. That doesn't mean bigger is better. If the fire gets to hot, you will not be achieving the smoking process and you will render at least half of your smoking chamber useless. Plus a hotter fire will burn too fast and dry out your meat. I am into low and slow. I am also into an efficient fire which will achieve a steady flow of heat without burning up a cord of wood.

Now ask additional questions based on what you have to work with.

How large is the 100# bottle? height x width?

 

[chinesebob]

The smell from the tanks will go away eventually. First thing - did you purge the tanks? By purging I mean - fill them up with soap and water and let them sit for about 4 days to a week. Even after you purge the smell will be there. Don't worry about that as long as you've purged them.

I gave up on building my own because it got to be so difficult with the tanks and I haven't had to professionally weld in close to 12 years so I'm more than a little rusty.

I settled for a spicewine and hopefully soon we'll be looking at something beautiful in my driveway other than my truck.

 

[Beerwolf]

WOW... OK... here we go


Tank dimensions are 14 1/2" Dia x 48" for smoke box, firebox is 14 1/4" x 18"

The firebox will be mounted UNDER the smoke box in the center of the span. It is being connected to the smoke chamber with a 12" x 5" rectangular tube that is 6" long.

The smoke chamber was an OLD tank that had been shot with a 9mm many years ago. I started cutting on it with a grinder before I heard all of the hazzards of "imbedded flammables" in the metal. Once I finished fabrication, I burned that thing out 2 times, getting it spit bouncing hot both times and turning the whole tank's brightly sanded surface BLUE.

The firebox was a little different, once I removed the valve, I filled the bottle with soapy water and let it sit for 4 days in the sun and repeated. I plan on burning it out as well, although neither tank has a hint of odor.


My Concerns:

With the firebox mounted in the center, do I want two smoke stacks at opposite ends, or just the one, since this is a fairly small chamber and the difference wont be much? I have 2 options I am considering

1. ONE stack, 3 or 4" in diameter ( depending on what I can scrounge from the Muffler shop)

2. TWO stacks at opposite ends of the smoke chamber 2 1/2" or 3" in diameter

The firebox will have one 3" adjustable damper at either end and will also have a ash clean out at the bottom.

Let me know if you need any additional information

 

[parrothead]

If the fire box comes up in the center, then you will want 2 pipes. One at each end for even distribution. With this, you may be able to choke one side off if you want and have different temps from one side to the other, but I would put the two in right off the bat.

 

[tony76248]

Another question is where will you be starting your smokestack? If you place it at roughly grate level you will be introducing much more smoke to the meat rather than having it come out of the top.

I initially thought one stack, then again, I was thinking offset with firebox at one end.

Have you already begun, if so, can you post us some pictures?

 

[Arlin_MacRae]

I'm with Greg and Tony: put in two stacks, and feed them from grate level or below.

Arlin

 

[Mooner]

Post some pics of the finished product. Im sure we're all curious how she's gonna turn out. Good luck!!

 

[Beerwolf]

Will DO! ( as soon as EX coughs up my camera)

I am about down to the point of fabbing the stacks and the air inlets, and then the Grilles.

So far my total outlay in cash is about 8 bucks for metal and 30 bucks for 2 spools of wire and maybe another 10 for grinding/cutting wheels. The tanks were a freebee, and the stand was made out of 1 7/8" chain link fence posts... (Yes I sanded the galvanized off before I welded it)

My time... is another story, actual fab time is actually pretty minimal, I MAY have 25 hours of actual work in it... not counting another 15 or 20 of sitting in a chair and staring or looking ideas online. But YES Id do it again..

 

[Beerwolf]

I finally "scammed" the pipe I will need for my stacks, 2 pc 4" x 48" long. I had another "brain fart" I want to ask about.... is there ever any situation where it would be an asset to be able to raise or lower the bottom portion of the stack? It wouldnt be something impossible to engineer in at the time of fabrication.... any thoughts?

 

[Beerwolf]

another question

OK... one of my buddies snagged some 4" tube for me as I asked... what he brought was SCHEDULE 80, the thick ****. Is there any reason that this WONT work as a smoke stack? I know its overkill, but hell its also free. I am planning on 2 stacks 3' long ( he gave me 6' of the stuff) My only concern is changing the center of gravity on the smoker.

Speaking of the smoker, I got the firebox on today and build a quick fire, Man that thing will be HOT. The firebox turned a nice shade of blue, and the smoke chamber actually reached the spit bouncing stage. The doors leaked a bit, But I am thinking that will go away once the stacks are installed. Next will be Grille Fab and paint and prep. I will be glad to be done with this and back on finishing the 10 gallon brewery I got bored with working on.