My First smoker build. 30” offset.

[Mgdwj]

I acquired a little bit of 30” pipe to build my first smoker. My plans are an offset smoker with a 60” cook chamber with a 30x24” firebox, and a vertical warming box. I know my firebox is a little oversized. I had a couple questions for the gurus out there.
1. I’ve read several places that the vertical warming box acts as part of your smoke stack. How much does it act as part of the smoke stack? Should I make the stack half as long as the calculators call for? More…less….

2. The transition between the cook chamber and the vertical box do I need to ad a piece of plate between the two that goes down to the lower grate level?

3. The heat diverter plate that goes from the firebox to the cook chamber. I had planes on cutting holes in it small on one end then transitioning to larger on the other end to hopefully more evenly distribute the heat. How far should it extend through the cook chamber? Does it need to be in flat or angled one way or another?

[OldUsedParts]

Good Score on the BBQ BODY.
Hopefully some of our Stick Burning Members will see this and offer some info and advise for you.
Good Luck

[k.a.m.]

I acquired a little bit of 30” pipe to build my first smoker. My plans are an offset smoker with a 60” cook chamber with a 30x24” firebox, and a vertical warming box. I know my firebox is a little oversized. I had a couple questions for the gurus out there.
1. I’ve read several places that the vertical warming box acts as part of your smoke stack. How much does it act as part of the smoke stack? Should I make the stack half as long as the calculators call for? More…less….
12" to 16" of 6" to 8" pipe is all you will need on top the vertical.

2. The transition between the cook chamber and the vertical box do I need to ad a piece of plate between the two that goes down to the lower grate level?
A lot of cookers like this have the opening into the vertical below the lower grate. I would probably have mine between the two.

3. The heat diverter plate that goes from the firebox to the cook chamber. I had planes on cutting holes in it small on one end then transitioning to larger on the other end to hopefully more evenly distribute the heat. How far should it extend through the cook chamber? Does it need to be in flat or angled one way or another?

I prefer adjustable tuning plates rather than a fixed plate with variable holes.

[GRailsback]

I have tuning plates in mine as well.

[Mgdwj]

1.
12" to 16" of 6" to 8" pipe is all you will need on top the vertical.

2.
A lot of cookers like this have the opening into the vertical below the lower grate. I would probably have mine between the two.

3.

I prefer adjustable tuning plates rather than a fixed plate with variable holes.[/quote]

Thanks for your input.
I’m also thinking about putting an air inlet on both side of my firebox. On smokers that I’ve had in the past that only had one inlet seemed to only burn on one side of the fire.

Would it be best to have one smaller air inlet on each end of the fire box or have a single large air inlet on one end of the firebox.

I had also thought of putting the firebox cylinder in a vertical position in relation to the cook chamber to have a flat top and bottom on the firebox. I know traditional the firebox is in a horizontal position in relation to the cook chamber. I don’t know if this would be a good idea or not. I haven’t seen any other pits with a fire box oriented that way.
Perhaps there is a reason that I haven’t seen it done before.

Any advice for cutting the doors so the don’t distort or spring when I cut them?

[k.a.m.]

1.
12" to 16" of 6" to 8" pipe is all you will need on top the vertical.

2.
A lot of cookers like this have the opening into the vertical below the lower grate. I would probably have mine between the two.

3.

I prefer adjustable tuning plates rather than a fixed plate with variable holes.

Thanks for your input.
I’m also thinking about putting an air inlet on both side of my firebox. On smokers that I’ve had in the past that only had one inlet seemed to only burn on one side of the fire.
Air inlets on opposite sides can be a good thing but on the same note they can fight each other causing a cross draft in your firebox. If you use this idea make sure either side is big enough not to rely on the other. I prefer my intakes to be at the end of the firebox to force air straight through.

Would it be best to have one smaller air inlet on each end of the fire box or have a single large air inlet on one end of the firebox.
Single inlet on the end.

I had also thought of putting the firebox cylinder in a vertical position in relation to the cook chamber to have a flat top and bottom on the firebox. I know traditional the firebox is in a horizontal position in relation to the cook chamber. I don’t know if this would be a good idea or not. I haven’t seen any other pits with a fire box oriented that way.
Perhaps there is a reason that I haven’t seen it done before.
I would keep it horizontal. If you want a flat top for warming something then add a plate.

Any advice for cutting the doors so the don’t distort or spring when I cut them?[/quote]
Are you using a torch, Plasma, or cut-off wheel?

[Mgdwj]

Air inlets on opposite sides can be a good thing but on the same note they can fight each other causing a cross draft in your firebox. If you use this idea make sure either side is big enough not to rely on the other. I prefer my intakes to be at the end of the firebox to force air straight through.
I’ll keep it to one air inlet on the end of the firebox.

Single inlet on the end.

I would keep it horizontal. If you want a flat top for warming something then add a plate.
I’ll keep it horizontal and break a piece of plate and weld to the top for a flat area. I use the flat area a lot to pre warm my wood before it goes in the firebox. I’ve found they ignite a lot quicker.

[/quote]
Are you using a torch, Plasma, or cut-off wheel?[/quote]
I’ll be using a combination of plasma torch and cutoff wheels for the doors. I wasn’t blessed with consistent torch skills. Part of my cuts look prefessional while other parts look like a drunk teenager did it with a hatchet. I’ve had welder working for me building drilling rigs that can cut welding rods in half lengthwise.


Thanks for taking the time to answer my questions. I would like to build it right the first time. I have used to many pits that don’t work very well, and takes constant tending to operate. I’ve have also used just a few that work like a dream and was able to load the firebox and it would run without tending for 2-3 hours with out the temp gauges moving more that 10-20 degrees. I would prefer to build a smoker like that the first time.

I have accumulated 95% of the materials for the smoker. As soon as deer season is over I’ll start the cutting and grinding.

[k.a.m.]

On 30" pipe I lay my doors out as follows. Top cut is 6" below TDC, the bottom cut is 1" below the 3:00 position.
Once it is laid out leave the four corners 1.5" in place. Leave the top center, bottom center left and right center 1.5" in place.
Here is a drawing of how I cut the doors.
NOTE: If the doors are going to spring they will there is nothing to stop this if the pipe or vessel are stressed. What you do is fit later by tweaking them.

[Mgdwj]

On 30" pipe I lay my doors out as follows. Top cut is 6" below TDC, the bottom cut is 1" below the 3:00 position.
Once it is laid out leave the four corners 1.5" in place. Leave the top center, bottom center left and right center 1.5" in place.
Here is a drawing of how I cut the doors.
NOTE: If the doors are going to spring they will there is nothing to stop this if the pipe or vessel are stressed. What you do is fit later by tweaking them.

I had planned something similar for the doors. Hadn’t come up with any measurements yet, but something similar. Plan was to cut out the doors in a manner like you illustrated. Using my wizard wrap get my circumference lines for the hinges so the are straight and put them together using a long piece of all thread to hold both hinges together.

Got my air damper drawn out. According to the smoker calculator mine calls for 50.89 square inches of air inlet. This one come out to 56.54 square inches. Will have about half and inch of overlap when it’s fully closed.

Is it better to have the air inlet opening vertical or horizontal?
I plan on building a fire grate that will be about 4-5 off the bottom of the firebox

[k.a.m.]

On 30" pipe I lay my doors out as follows. Top cut is 6" below TDC, the bottom cut is 1" below the 3:00 position.
Once it is laid out leave the four corners 1.5" in place. Leave the top center, bottom center left and right center 1.5" in place.
Here is a drawing of how I cut the doors.
NOTE: If the doors are going to spring they will there is nothing to stop this if the pipe or vessel are stressed. What you do is fit later by tweaking them.

20231219100846418.jpg

I had planned something similar for the doors. Hadn’t come up with any measurements yet, but something similar. Plan was to cut out the doors in a manner like you illustrated. Using my wizard wrap get my circumference lines for the hinges so the are straight and put them together using a long piece of all thread to hold both hinges together.

Got my air damper drawn out. According to the smoker calculator mine calls for 50.89 square inches of air inlet. This one come out to 56.54 square inches. Will have about half and inch of overlap when it’s fully closed.

image.jpg

Is it better to have the air inlet opening vertical or horizontal?
I plan on building a fire grate that will be about 4-5 off the bottom of the firebox

I like the inlet size it should serve you well. I would put your openings vertical so you can draw under and over your coal base.

[1MoreFord]

Here's some more thoughts on pit building and layout. I ran across this info not long after I discovered BBQ Forums. It's now relegated to the internet archives.

Cyclops
http://web.archive.org/web/200602060924 ... lops.shtml

[OldUsedParts]

^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^

[k.a.m.]

Here's some more thoughts on pit building and layout. I ran across this info not long after I discovered BBQ Forums. It's now relegated to the internet archives.

Cyclops
http://web.archive.org/web/200602060924 ... lops.shtml

That is a name I haven't heard in many years.

[Mgdwj]

Well I got my hinges, handles and dampers drawn up in CAD and dropped off the metal with my cnc plasma guy. Waiting on him to get them cut out. I also dropped off a couple sticks of 2x1/4” strap with a shop for them to roll me out some circles to use as door straps.
I stopped by our local steel supplier and rummaged through their secondary pieces of plate and found a piece that will be big enough for end caps. Also got most the material for the pull out meat racks and tracks.
I built a circle cutting guide for our plasma cutter.
I got a free boat trailer to mount the pit on. I just had to unload the old junk boat off of it and haul it off to a trash pit. I learned that it’s harder than I thought to sling a boat off of a trailer.

I ran the math today to figure out how much my doors were going to weigh, and it looks like they will be right at 55lbs each on the cook chamber. I planned on waiting until I get the doors cut out and hinges installed and go from there as to if I’m adding counterweights.

[Rambo]

Good luck; sounds like you’re cooking on the front burner. Listen closely to KAM’s post