So. Cal Smoker

[hEdly]

OK, so I want to build grill. It will end up being primarily used for the men's ministry at my church.

One of the requirements that I have for it is to not only be able to smoke meat, but also transform into a direct heat charcoal grill. Then when we have time we can spend half a day smoking lots of meat. Or if we need to do a hamburger & hot dog event, we can make a couple changes and have a standard grill.

So after some searching, I got a 53" long, 30" dia, 3/16" thick tube that some coworkers found out in the ocean. Here's some photos from this evening when my father-in-law and I got it out of my truck.


{53" of pure cooking potential}


{seam with rivets}


{needs a bit of cleaning}

So I gotta get it sand blasted. I think I'm going to put a single opening about 44" long.

I need to figure out if I am going to do a reverse flow or the type with the box centered and behind/below the main body. I really like that style because it keeps the overall length down.

I'm using a 3D modeling program to make the design so I hope to have some good design images up in a couple weeks or so.
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Just a cooker, not a chef.

[Sgt. Stel]

Look forward to seeing pics of you build and the ministry events it will be supporting!

Sgt. Stel
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T&K Gravity Feed, Medium

[hEdly]

Now, I am not a welder, but I am an engineer. Having never designed one of these (but lots of stuff for the ocean), I may be using steel angle that is too beefy. So let me know if I can knock it down a bit.

So here is my first cut. Sides (that I have to find or buy) will probably be 1/4" steel (tube thickness is 3/16").

Bottom rack is about 2 inches below centerline. I am using 1x1x3/16 steel angle for grate frames and 1.5x1.5 angle for grate supports. I am probably going to use some kind of expanded steel for the grate.

What is a good distance between the top and bottom racks? Right now I have about 7 inches.

Still need to figure out if it will be a reverse flow or something (that seems to be the favorite design on this site and for good reason).

Lookin' forward to comments.

R/hEdly
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Just a cooker, not a chef.

[hEdly]

Here is a link to the 3D model:
https://docs.google.com/leaf?id=0B6UdrcGSE8QkZjE1ZTkwMWEtMzg5Yi00OTY4LWJlM2QtMmRlZWUzNTg2MTEw&hl=en&authkey=CLH1n60F

You will need a dwf viewer to open it. You can get one for free from Autodesk. it is free and really a light weight program. Here is the link
http://usa.autodesk.com/adsk/servlet/pc/index?siteID=123112&id=12423405
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Just a cooker, not a chef.

[hEdly]

So you can see I have made some more progress with the design. I downloaded KAM's excel spreadsheet. Here's what I have so far.

Cooker Volume: 37444.5 cu. in.
Firebox volume: 13,200 cu in. (22x20x30)
FB to chamber op: 107 cu in. (2qty 8.25 circles)
FB inlet opening: 48 sq. in. (4qty 3in x 4 in)
Exhaust length: 38 inches of 4.5in schd 10 pipe

Spacing between bottom and top racks: 6.5"
Spading between top rack and chamber: 6"

Bottom cooking surface: 19.5"w x 27"D
top cooking surface: 19.5"w x 21"D

now, some questions.
1) why does the exhaust pipe need to be so long. KAM's calculator says it needs to be 46.25" when using the ID of 4.5" schd10.

2) what angle should the flow plate be at? I have seem some on a constant angle and one with a sharp bend near cook chamber opening. should the angle be adjustable?

3) how much space do I need to leave between the smoke plate and the end? Should the space be adjustable?
[that seems to be the only calculation missing from KAM's awesome spreadsheet]

4) I think I saw it somewhere...how far down should the flow plate be from the bottom rack?

any other recommendations would be greatly appreciated?

Thanks in advance,
hEdly.
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Just a cooker, not a chef.

[k.a.m.]

hEdly, Nice score on the pipe I look forward to watching your progress.
First let me say I appreciate the kind words on the spread sheet but the credit goes to Alien and Tom C for bringing it to life I just get a lot of mileage out of it figuring cookers for members that have trouble with it.
I like the distance you have between your grates, 6'' to 7'' is a good spread.

I also like your choice of rail and grate frame material, I have moved up to 1'' x 1'' x 1/4'' angle for my frames but the 3/16'' will work nicely.

For your grate material the norm is #9 3/4" flat expanded.

1)
The calculator figures the volume of exhaust needed to create the proper draw for the cooker, so the smaller diameter pipe it will increase the length to accommodate your needs. In your case if you increase the diameter to 5'' you would need an exhaust length of 34'' and 6" would need to be around 24''. I would go with the 5'' or 6''. On your size cooker I do not think your going to like the 4'' exhaust unless you put duals on her.

2)
I ran the R/F plate on mine with a 1/2'' drop to the center forward and aft and the entire plate slopes 1'' away from the firebox.

3)
The distance between the end of the R/F plate and cooker wall needs to at least equal your firebox to cooking chamber opening so there is not a bottle neck of heat/smoke.

4)
The R/F plate in my opinion can be between 1'' and 5'' between your bottom rack.
I think I covered everything if I missed one just let me know.
_________________
Always remember slow and steady wins the race.

Hybrid Cooker

[hEdly]

So, here is where the virtual design stands so far:


Here is a link to the model:
https://docs.google.com/leaf?id=0B6UdrcGSE8QkZjE1ZTkwMWEtMzg5Yi00OTY4LWJlM2QtMmRlZWUzNTg2MTEw&sort=name&layout=list&num=50

I found out if you open the model link in internet explorer, IE7 or IE8 natively supports dxf files, so you will have the viewing tools which allows you to rotate, zoom in/out, hide parts, etc.

You can see I have the flow plate, drip catch and drip drain. I also added in the firebox air intakes, firebox door, and fuel box.

If you look closely I also added in one of the charcoal holders. These are optional. It allows me to make a direct heat grill for doing quick jobs like hamburgers and hotdogs. I would remove the top grills.

I re-measured the thickness, it is actually more like 0.15" thick, probably 9 gauge steel that's been rolled.

Currently you can see that I have a center support. But I lose about 144 sq in of cooking surface. I'd like to remove it, but I am worried that the thickness won't support the door and cooking surfaces.

Well, what if I put a 3/16" or 1/4"thick x 1" wide piece of flat stock on the inside of the door opening at the top and bottom.

Also, the whole time I am designing this thing I have been thinking about adding on one of those "rib cookers" above the firebox.

So, here are my questions...

1. Can I get rid of the center support if the pipe is .15" thick?

2. Do I need to strengthen the door opening? If so any recommendations?

3. What is the cooking chamber above the firebox used for and what temps should it attain?

4. How tall should the chamber be?

5. Where should the heat from the main chamber enter this box?

6. Do I need a damper on the current exhaust pipe? (or if I build the second cooking chamber, do I need a damper on it's exhaust?) What are they for other than keeping the rain out when not it use?

7. If I build the second chamber, do I need a damper between the main chamber and the second one?

8. Do I need a damper between the firebox and main chamber? I've seen some designs with them.

9. If I build the chamber above the firebox, does it also need a ~24" long exhaust stack out the top? With/without a damper ?

10. Any other info about this second cooking chamber I should know/think about?

Thanks again for the wealth of information provided by this site. I am hoping that I can start building this thing for real some time in April.

Cheers,
hEdly
_________________
Just a cooker, not a chef.

[k.a.m.]

hEdly, I do not think the center support is needed. If you want to stiffen those areas I would use 1" x 1" x 1/4" angle. The flat bar will do little unless it is placed on edge. You can run your rail supports for the bottom as you have them utilizing two bottom racks. On the upper rack you can go one rack using 1" x 1" x 1/4" angle and by adding a longitudinal middle angle iron support your length without the middle supports.
The box above the firebox is more of a warming chamber, the one on my R/F build has a damper that allows for smoke to enter. The chamber runs at around 140° when the main chamber is at around 225°
Questions.

1.)Can I get rid of the center support if the pipe is .15" thick?
In my opinion yes, answered above.

2.)Do I need to strengthen the door opening? If so any recommendations?
You can if you like I answered above.

3.)Do I need to strengthen the door opening? If so any recommendations?
Answered above.

4.)How tall should the chamber be?
I made the chamber on mine 30" tall x 30" wide x about 20" deep

5.)Where should the heat from the main chamber enter this box?
I prefer the smoke to enter right above the R/F plate, this box is warmed mostly by radiant heat from your firebox.

6.)Do I need a damper on the current exhaust pipe? (or if I build the second cooking chamber, do I need a damper on it's exhaust?) What are they for other than keeping the rain out when not it use?
I would put caps on all the exhausts it keeps the weather and varmints out.

7.)If I build the second chamber, do I need a damper between the main chamber and the second one?
Yes in my opinion you need the damper. It will close off the box when you do not want smoke to enter it.

8.)Do I need a damper between the firebox and main chamber?
I've seen some designs with them.
In my opinion no the damper is not needed, it is more of an option that allows you to close off the heat/smoke if you choose during a cook.

9.)If I build the chamber above the firebox, does it also need a ~24" long exhaust stack out the top? With/without a damper ?
No you do not need that long a stack on your warming chamber. I used two 3" x 6" long stacks on mine.

10.)Any other info about this second cooking chamber I should know/think about?
Not that I can think of. Here is a link to my build that shows the warming chamber, also the damper between them. I hope this helps.
http://www.thesmokering.com/forum/viewtopic.php?t=32283
_________________
Always remember slow and steady wins the race.

Hybrid Cooker