A few weeks ago I posted a cabinet smoker build I'd done and at the time, I was really happy with it, especially based on an extreme lack of metal fabricating experience. After running the smoker through the paces a few times I realized there were some major deficiencies. I was confident that the concept was sound but there were some fundamental flaws in execution. Did a couple mods to it which improved performance but it still missed several of my intended marks by a bunch. I decided to build a new one and turn the first one into scrap metal for future projects...whatever they may be. Once the decision was made to build a new one I spent hours doing every test on the first one I could think of. Wanted to find every possible way to improve the second one to meet (or hopefully exceed) my expectations. Here are the results of my testing:
Heat Distribution: I did not allow nearly enough opening space between the fire box and cook chamber for efficient transfer of heat and smoke. I used 2) 1" x 3" channels on each side as openings between the firebox and cook chamber. Those actually netted me 3/4" x 2 3/4" taking into account the thickness of the steel for a total of 8 1/4" square inches. Nowhere near enough. My thoughts were that by default the heat would effortlessly rise through the channels according to the laws of physics. That was a misnomer on my part.
Lower Damper Placement: I set the lower dampers fairly high to allow easy access to the control knob for the propane valve. Bad idea. The way the heat was coming off the heat deflector, and not having enough space to rise into the cook chamber, the heat was going right out of the dampers.
Chimney Placement: I installed the chimney on the first one centered left to right but at the back of the of the unit. Not efficient in the least. As the heat started to rise into the chimney and creating a draw as it's supposed to do, it was pulling the heat from the front to the back. I had balanced temps top to bottom but not front to back. It was about 20 degrees hotter in the back than it was in the front.
Heat Retention: I chose to use the steel on the first one based on the Rec Tec and the Weber. Both of those cookers have very thin steel but maintain temps effortlessly. I used much thicker steel but it did not have the same effect. Another misnomer on my part....and I should have known better.
So now to the new build. You'll see a lot of similarities between this one and the first one. Here are the side panels. I used 1" x 2" instead of 1" x 1" tubing to create a much wider space from the fire box to the cook chamber. Please note that each compartment is banded with 1/2" x 1/2" steel angle. I also cut the damper openings about 3 1/2" lower.
I located some industrial grade high heat foam insulation that has a Class 1 / Class A fire rating, which is the same as masonry products or fiber cement board. It is 1/4" thick and super easy to cut for installation. Lined both panels with 2 layers of it
The second steel plate installed inside over each section
Complete both side panels and attach them to the back
Build the top. This time I centered the opening for the top stack.
Attach the top to the back and side panels. This is also used to square up the sides.
Add 4 layers of insulation to the top
Install the second steel panel.
Build the heat deflector plate, attach it to the first panel going in between the fire box and cook chamber. Notice the openings on the sides. I went from the 4 small channels to a full 1 1/2" width running the full 18" length front to back for a total of 54 square inches of space. That's about a 650% increase in volume over the last one for a cook chamber that's half the size.
Install 4 layers of insulation in the bottom.
Band the entire back panel with 3/4" x 3/4" angle and install 3 layers of insulation
Add the second steel panel to the back and install the bottom. This time I drilled for the casters and bolted them on before welding the bottom. Last time is was no fun at all trying to hold those things in place and getting the bolts through from the inside. This was MUCH easier. Oh well...live and learn I guess.
The cook chamber door. Also banded with 3/4" x 3/4" angle and 3 layers of insulation installed then a second steel panel welded over the insulation.
Mount the doors, spring handle, tack the lower dampers in place, and fabricate one of the door latches. Decided not to do all the latches yet because if the doors settle the least bit when I stand it up I'll be cutting all the stuff off and redoing it. Also, this time I didn't mess around with chintzy junk hinges. I used some seriously heavy duty ones this time.
If any of you are religious, I could use a prayer or two right about now please. This thing is heavy beyond belief!!
Prayers answered. Thank you!!
Weld the top stack on, fabricate and install the rest of the door latches
Build small shelves for the sides, sleeve through one side for access getting temp probes through, and tack on the first of the 2-part damper. The sleeve is offset intentionally.
Build and install the top damper.At this point it's time to buff, polish, and prep it for paint.
Paint done. Time for final assembly.
While the paint is curing I build the cooking grates
They fit!!
Install all the bling...and there's a lot of it, almost to the point of being gaudy. Thing is that I got tired of burning my fingers every time I needed to do anything with the other one so I put stay-cool spring handles on everything.
Out to the patio, it's final resting place. Install the propane burners, connect the gas line, and fire this baby up for the initial burn-in
Did the burn-in for about 4 hours and decided to toss some thick cut pork loin chops on for smoke and sear.
A lazy man's dinner but it was oh so good, and oh so gratifying
It seems as though a lot of people are getting creative and building their own cookers recently so I thought I'm go into a lot of detail here so others can learn from my mistakes on the first build. It also seems as though the cabinet style smokers are gaining in popularity, and for good reason{s). They are very efficient, very effective, and you can cook a ton of food on a smoker that takes up very little space on the patio. Some folks just don't have 6-8 feet to dedicate to a conventional offset. This one is 24" wide, 18" deep, and the entire box is 48" tall with a 3 foot tall cook chamber. With that small of a unit, I could probably still do 6 full packer briskets at a time.
To say this build was a success would not be doing it justice. It hit on every mark I intended with the first one...and I mean a bulls-eye hit. Heat retention is outstanding with the entire cook chamber being double walled steel and insulated. At 250 degrees the sides of the cook chamber are barely warm. At 325 the sides shot between 118 and 120. That's doing well keeping the heat inside where it belongs. When I fired it up Friday it was 55 degrees and the smoker was up to 200 in about 10 minutes and at 275 in less than 20 minutes. That tells me I got ample opening space between the fire box and cook chamber, and the heat is not flowing out the dampers like the other one. With the top stack in the center it is drawing heat evenly from all 4 sides so chamber temps are perfectly balanced throughout. Mission accomplished!!
Many many thanks to all who have braved this thread. Once again also, my apologies for the absence the past week and a half. This project has been very exciting and somewhat all-consuming. I've checked and read most of the recent threads but time has not been available to reply with this thing sitting in the garage begging to be completed
Got a few other things to catch up on around the house then I'll have time to be part of the SMF family again....assuming I'm still welcome after abandoning you twice in the last couple months
Off to get some breakfast going,
Robert
Heat Distribution: I did not allow nearly enough opening space between the fire box and cook chamber for efficient transfer of heat and smoke. I used 2) 1" x 3" channels on each side as openings between the firebox and cook chamber. Those actually netted me 3/4" x 2 3/4" taking into account the thickness of the steel for a total of 8 1/4" square inches. Nowhere near enough. My thoughts were that by default the heat would effortlessly rise through the channels according to the laws of physics. That was a misnomer on my part.
Lower Damper Placement: I set the lower dampers fairly high to allow easy access to the control knob for the propane valve. Bad idea. The way the heat was coming off the heat deflector, and not having enough space to rise into the cook chamber, the heat was going right out of the dampers.
Chimney Placement: I installed the chimney on the first one centered left to right but at the back of the of the unit. Not efficient in the least. As the heat started to rise into the chimney and creating a draw as it's supposed to do, it was pulling the heat from the front to the back. I had balanced temps top to bottom but not front to back. It was about 20 degrees hotter in the back than it was in the front.
Heat Retention: I chose to use the steel on the first one based on the Rec Tec and the Weber. Both of those cookers have very thin steel but maintain temps effortlessly. I used much thicker steel but it did not have the same effect. Another misnomer on my part....and I should have known better.
So now to the new build. You'll see a lot of similarities between this one and the first one. Here are the side panels. I used 1" x 2" instead of 1" x 1" tubing to create a much wider space from the fire box to the cook chamber. Please note that each compartment is banded with 1/2" x 1/2" steel angle. I also cut the damper openings about 3 1/2" lower.
I located some industrial grade high heat foam insulation that has a Class 1 / Class A fire rating, which is the same as masonry products or fiber cement board. It is 1/4" thick and super easy to cut for installation. Lined both panels with 2 layers of it
The second steel plate installed inside over each section
Complete both side panels and attach them to the back
Build the top. This time I centered the opening for the top stack.
Attach the top to the back and side panels. This is also used to square up the sides.
Add 4 layers of insulation to the top
Install the second steel panel.
Build the heat deflector plate, attach it to the first panel going in between the fire box and cook chamber. Notice the openings on the sides. I went from the 4 small channels to a full 1 1/2" width running the full 18" length front to back for a total of 54 square inches of space. That's about a 650% increase in volume over the last one for a cook chamber that's half the size.
Install 4 layers of insulation in the bottom.
Band the entire back panel with 3/4" x 3/4" angle and install 3 layers of insulation
Add the second steel panel to the back and install the bottom. This time I drilled for the casters and bolted them on before welding the bottom. Last time is was no fun at all trying to hold those things in place and getting the bolts through from the inside. This was MUCH easier. Oh well...live and learn I guess.
The cook chamber door. Also banded with 3/4" x 3/4" angle and 3 layers of insulation installed then a second steel panel welded over the insulation.
Mount the doors, spring handle, tack the lower dampers in place, and fabricate one of the door latches. Decided not to do all the latches yet because if the doors settle the least bit when I stand it up I'll be cutting all the stuff off and redoing it. Also, this time I didn't mess around with chintzy junk hinges. I used some seriously heavy duty ones this time.
If any of you are religious, I could use a prayer or two right about now please. This thing is heavy beyond belief!!
Prayers answered. Thank you!!
Weld the top stack on, fabricate and install the rest of the door latches
Build small shelves for the sides, sleeve through one side for access getting temp probes through, and tack on the first of the 2-part damper. The sleeve is offset intentionally.
Build and install the top damper.At this point it's time to buff, polish, and prep it for paint.
Paint done. Time for final assembly.
While the paint is curing I build the cooking grates
They fit!!
Install all the bling...and there's a lot of it, almost to the point of being gaudy. Thing is that I got tired of burning my fingers every time I needed to do anything with the other one so I put stay-cool spring handles on everything.
Out to the patio, it's final resting place. Install the propane burners, connect the gas line, and fire this baby up for the initial burn-in
Did the burn-in for about 4 hours and decided to toss some thick cut pork loin chops on for smoke and sear.
A lazy man's dinner but it was oh so good, and oh so gratifying
It seems as though a lot of people are getting creative and building their own cookers recently so I thought I'm go into a lot of detail here so others can learn from my mistakes on the first build. It also seems as though the cabinet style smokers are gaining in popularity, and for good reason{s). They are very efficient, very effective, and you can cook a ton of food on a smoker that takes up very little space on the patio. Some folks just don't have 6-8 feet to dedicate to a conventional offset. This one is 24" wide, 18" deep, and the entire box is 48" tall with a 3 foot tall cook chamber. With that small of a unit, I could probably still do 6 full packer briskets at a time.
To say this build was a success would not be doing it justice. It hit on every mark I intended with the first one...and I mean a bulls-eye hit. Heat retention is outstanding with the entire cook chamber being double walled steel and insulated. At 250 degrees the sides of the cook chamber are barely warm. At 325 the sides shot between 118 and 120. That's doing well keeping the heat inside where it belongs. When I fired it up Friday it was 55 degrees and the smoker was up to 200 in about 10 minutes and at 275 in less than 20 minutes. That tells me I got ample opening space between the fire box and cook chamber, and the heat is not flowing out the dampers like the other one. With the top stack in the center it is drawing heat evenly from all 4 sides so chamber temps are perfectly balanced throughout. Mission accomplished!!
Many many thanks to all who have braved this thread. Once again also, my apologies for the absence the past week and a half. This project has been very exciting and somewhat all-consuming. I've checked and read most of the recent threads but time has not been available to reply with this thing sitting in the garage begging to be completed
Got a few other things to catch up on around the house then I'll have time to be part of the SMF family again....assuming I'm still welcome after abandoning you twice in the last couple months Off to get some breakfast going,
Robert
, you sure did turn out a fine looking smoker, Robert. I am truly in awe, that beast is a beauty and I can't wait to see what other food you cook it. You may have found a great part time job if you wanted one...
