- Feb 10, 2009
- 398
- 16
Working on a concept for building an LP gas smoker out of a 55 gallon drum. The intended smokee is a variety of smoked sausages but could escalate into using it for ribs, birds, etc.
The sausage smoking process is to start with temps in range of 120* to 130* for an hour or so and draft and dampers wide open to dry the sausage. Then medium to heavy smoke is added for a couple hours, at the same temps.....and when the smoke is completed, closing down the draft and dampers and cranking temps up to 160 to 170 degrees until the internal temp of the sausage is 152 degrees. This can take 4 to 6 hours or more, depending on the size of the sausage. During this whole time, smoker temps shouldn't exceed 170 for more than a few minutes. Essentially, what you need is a very precise, low temp oven with potential to add smoke.
This started with an idea to use my UDS for this, but quickly found out that keeping steady temps in the range of 160* to 170* for hours on end wasn't going to be easy using charcoal or wood. Most small commercial smokers use electric hot plates or gas burners and are relatively small in size. What I should do is chuck the idea of building one and buy a GOSM......but where is the fun in that?
So here is the plan:
55 gallon drum (with option to upgrade to an 85 gallon drum).
LP gas burner (more on this later).
Racks for hanging sticks or grill.
Draft/damper control.
Here is the first prototype:
Most UDS smokers don't fit the billing of ugly. This one does! It's been burned out, but nothing more. Paint will come later if it works. No loss really, the barrel was free.
I started out with the small camp stove burner on a 2# bottle, set under the middle of the barrel. Early tests showed it would get the temps up, but that was on a 70 degree day. But during a test smoke when it was 40* F out and the wind blowing, temps maxed out at 120*. I also went through 2 plus bottles on this smoke, so this was not going to work. Damper control might change this. More on this later.
So I replaced the small burner, which probably has 8,000 BTU max output, with a Bayou Classic cooker, max 160,000 BTU. Supposedly, it will throttle down low enough to simmer a cup of coffee, but not for me. Get that low enough and the wind blows it out.
But it goes together like this:
Hole in the bottom of the barrel......note the bricks for the heat baffle to rest on:
The distance of the baffle to the burner is about 8 inches, so the baffle plate....the lid off a 30 gallon drum......doesn't get hot enough to cause wood chips to smoke at initial smoking temps (less than 130*). So I have considered using a trashed out dutch oven.....the kind without legs:
A load of chips in this will smolder about 2 to 3 hours. Concern is that grease might get on them, but at these low temps, should not flare up. May if I was smoking a butt or something, with grease and higher temps. The smoke pan needs to be under the baffle for doing this.
For low tech, I hang sausages on these sticks, which also prop up the lid:
There is probably a ratio of draft or damper area to box size, but I don't know what that is. Most commercial smokers seem to use a 4 inch plus damper on a small box. The two inch bung hole is roughly 25% the area as a 4 inch hole, which has about 12.5 square inches of area. My method left a gap of 1 inch between the barrel and lid, with a 22 inch diameter......and 69 inch circumference.......or 69 square inches of draft area. All my heat is escaping, yet with the cooker throttled down, I have trouble getting temps down to 125*. Somewhere in there is also the problem of too much heat and air moving through, drying out the sausage too much. So the next step is to devise some internal racks so I can drop the lid a little. Or stick with my first smoke solution, which was a emergency "blanket" draft.....a nasty old wet beach towel:
What I think I need is a smaller burner. I can buy a 40,000 BTU burner, perhaps mounting it on the same cooker frame?
A different option was to ditch the cooker and insert the burner inside the barrel. For that, you need a burner and here was an option:
This is a burner and intake venturi, connected by a variable length of black steel pipe, which could be stuck through the side of the barrel near the bottom. But this is also a 160,000 BTU burner.....too hot. And now you have gas inside the barrel with smoldering wood chips. If the flame goes out and gas continues to flow, you have the makings for a pretty spectacular gas explosion. So one of these designs now has to have a thermocouple with gas shutoff.
If I (we) get this figured out, maybe I can adapt the design to this barrel:
That is an 85 gallon heavy steel haz mat drum. Lots of options with this.
The sausage smoking process is to start with temps in range of 120* to 130* for an hour or so and draft and dampers wide open to dry the sausage. Then medium to heavy smoke is added for a couple hours, at the same temps.....and when the smoke is completed, closing down the draft and dampers and cranking temps up to 160 to 170 degrees until the internal temp of the sausage is 152 degrees. This can take 4 to 6 hours or more, depending on the size of the sausage. During this whole time, smoker temps shouldn't exceed 170 for more than a few minutes. Essentially, what you need is a very precise, low temp oven with potential to add smoke.
This started with an idea to use my UDS for this, but quickly found out that keeping steady temps in the range of 160* to 170* for hours on end wasn't going to be easy using charcoal or wood. Most small commercial smokers use electric hot plates or gas burners and are relatively small in size. What I should do is chuck the idea of building one and buy a GOSM......but where is the fun in that?
So here is the plan:
55 gallon drum (with option to upgrade to an 85 gallon drum).
LP gas burner (more on this later).
Racks for hanging sticks or grill.
Draft/damper control.
Here is the first prototype:
Most UDS smokers don't fit the billing of ugly. This one does! It's been burned out, but nothing more. Paint will come later if it works. No loss really, the barrel was free.
I started out with the small camp stove burner on a 2# bottle, set under the middle of the barrel. Early tests showed it would get the temps up, but that was on a 70 degree day. But during a test smoke when it was 40* F out and the wind blowing, temps maxed out at 120*. I also went through 2 plus bottles on this smoke, so this was not going to work. Damper control might change this. More on this later.
So I replaced the small burner, which probably has 8,000 BTU max output, with a Bayou Classic cooker, max 160,000 BTU. Supposedly, it will throttle down low enough to simmer a cup of coffee, but not for me. Get that low enough and the wind blows it out.
But it goes together like this:
Hole in the bottom of the barrel......note the bricks for the heat baffle to rest on:
The distance of the baffle to the burner is about 8 inches, so the baffle plate....the lid off a 30 gallon drum......doesn't get hot enough to cause wood chips to smoke at initial smoking temps (less than 130*). So I have considered using a trashed out dutch oven.....the kind without legs:
A load of chips in this will smolder about 2 to 3 hours. Concern is that grease might get on them, but at these low temps, should not flare up. May if I was smoking a butt or something, with grease and higher temps. The smoke pan needs to be under the baffle for doing this.
For low tech, I hang sausages on these sticks, which also prop up the lid:
There is probably a ratio of draft or damper area to box size, but I don't know what that is. Most commercial smokers seem to use a 4 inch plus damper on a small box. The two inch bung hole is roughly 25% the area as a 4 inch hole, which has about 12.5 square inches of area. My method left a gap of 1 inch between the barrel and lid, with a 22 inch diameter......and 69 inch circumference.......or 69 square inches of draft area. All my heat is escaping, yet with the cooker throttled down, I have trouble getting temps down to 125*. Somewhere in there is also the problem of too much heat and air moving through, drying out the sausage too much. So the next step is to devise some internal racks so I can drop the lid a little. Or stick with my first smoke solution, which was a emergency "blanket" draft.....a nasty old wet beach towel:
What I think I need is a smaller burner. I can buy a 40,000 BTU burner, perhaps mounting it on the same cooker frame?
A different option was to ditch the cooker and insert the burner inside the barrel. For that, you need a burner and here was an option:
This is a burner and intake venturi, connected by a variable length of black steel pipe, which could be stuck through the side of the barrel near the bottom. But this is also a 160,000 BTU burner.....too hot. And now you have gas inside the barrel with smoldering wood chips. If the flame goes out and gas continues to flow, you have the makings for a pretty spectacular gas explosion. So one of these designs now has to have a thermocouple with gas shutoff.
If I (we) get this figured out, maybe I can adapt the design to this barrel:
That is an 85 gallon heavy steel haz mat drum. Lots of options with this.