New build (Budget Build)

[figuredmeout]

Let me ask you this how critical it the wall thickness for the stack I know the RF plate and CC side need the thermal mass of thicker wall but would say 0.125 wall be fine for the stack

 

[lendecatural]

Wall thickness is not critical since it relies on minimum volume to create a draft. You can use the 4" and make it 32" and it will draw better than  a 3" at 36".

 

[lendecatural]

Wall thickness is not critical since it relies on minimum volume to create a draft. You can use the 4" and make it 30" and it will draw better than  a 3" at 36".

Feldon's has a note about chimney length.

"Chimney Size
Enter the diameter of your chimney pipe to find out how long it should be.
  • A chimney that is too short may produce insufficient draft (drawing of air). A chimney that is too long may cause the air to cool before it exits, reducing effective draft and worse, dripping of exhaust materials onto food!
  • Many horizontal smokers have an exhaust between 30-40 inches in length, but there is no hard and fast formula."

Don't forget to multiply the FB to CC opening area that you get from Feldon's using a theoretical firebox of 100% by 1.5 to account for the reverse flow configuration of your smoker.

 

[gary s]

Thickness of the Pipe for the stack is not critical I use Std. schedule 40 on ours.  Your FB to CC opening should be   61.1 Sq. in.   

IMG_20140830_115453_293.jpg

• gary s
• Aug 30, 2014

 

[gary s]

 FB to CC opening should be   61.1 Sq. in.   You have an 18" pipe wall thickness 1/4"       So   A to B should be 17 1/2"      C should be 3 1/2"

IMG_20140830_115453_293-1.jpg

• gary s
• Aug 30, 2014

 

[figuredmeout]

4"x30" stack it is

So by my calculations I need 60sq in under the RF. Does anyone have the formula to figure how tall to the peak of the arc of the CC/FB opening should be to get this area

 

[figuredmeout]

Thanks

 

[figuredmeout]

Ok so I have a bad habit of over thinking things so please excuse me if this is a stupid question but if I make A to B 17 1/2" wouldn't that make C a lot more than 3 1/2" or will making it an arc add enough length to reach 17 1/2"

 

[lendecatural]

Yours will be a football shaped hole, therefore you need two segment areas to get up to the total required of about ~60 sq-in. 

http://www.1728.org/circsect.htm

Circle calculator.jpg

• lendecatural
• Aug 30, 2014

Circle calculator 2.jpg

• lendecatural
• Aug 30, 2014

The chord will be 13.84 inches across and 3.25" inches from the bottom of the cook chamber to the middle and another 3.25" to the top to complete the football. The arc will have a radius of your pipe at 9".

 

[lendecatural]

 Ok so I have a bad habit of over thinking things so please excuse me if this is a stupid question but if I make A to B 17 1/2" wouldn't that make C a lot more than 3 1/2" or will making it an arc add enough length to reach 17 1/2"

You aren't over thinking things, see the above calculator and the resultant numbers. Things will be different if you don't butt the two pipe pieces together end to end but rather mount the firebox perpendicular to the CC.

 

[figuredmeout]

Thanks I'm going to start layout and cutting on Tuesday so I should have more pictures to post soon

 

[gary s]

LenDecaturAL is exactly right, for some reason I was thinking you were going with a square firebox, even my example was for a square box My Bad.

Gary S

 

[figuredmeout]

No problem I appreciate the help I would actually prefer a square firebox but it's a budget build and the pipe is free

So for anyone keeping track so far total cost is $0

 

[gary s]

The smoker in my Avatar was built of of stuff we had laying around, the only thing we bought was a sheet of expanded metal.

Gary

 

[gary s]

How are you coming ? Any new pictures

Gary S

 

[figuredmeout]

I got the pipe cut into the 60" CC and the 24" FB.  I am getting the plate for the ends I am hoping to get back out and work on it some this weekend I hope to have more pictures by the first of the week at the latest

 

[gary s]

It's exciting to build a new smoker, and everyone can't witt to get finished  and start smoking, BUT take your time, think things through, if unsure or have questions, just ask, do research.

Be looking forward to watching your smoker come together.

Gary S

 

[figuredmeout]

IMG_0721.JPG

• figuredmeout
• Sep 10, 2014

IMG_0722.JPG

• figuredmeout
• Sep 10, 2014

IMG_0723.JPG

• figuredmeout
• Sep 10, 2014

IMG_0724.JPG

• figuredmeout
• Sep 10, 2014

Got my pipe cut and ends cut and cleaned up and tacked in place also got the RF plate cut hoping to cut the doors and RF plate installed later this week.

 

[gary s]

Looking good

Gary

 

[figuredmeout]

What is the minimum distance between the RF plate and the grate.  In order for have the 61 sq in it puts my RF plate up around 7 in giving me 2 in or less is this going to cause me problems down the road?

Thanks

Tanner