MMMM.. BRISKET..
The BBQ BRETHREN FORUMS.  



Our Homepage Donation to Forum Overhead Welocme Merchandise Associations Purchase Subscription
Go Back   The BBQ BRETHREN FORUMS. > Discussion Area > Q-talk

Notices

Q-talk *ON TOPIC ONLY* QUALITY ON TOPIC discussion of Backyard BBQ, grilling, equipment and outdoor cookin' . ** Other cooking techniques are welcomed for when your cookin' in the kitchen. Post your hints, tips, tricks & techniques, success, failures, but stay on topic and watch for that hijacking.


Reply
 
Thread Tools
Old 07-05-2014, 05:31 PM   #1
Mankussm
Found some matches.
 
Join Date: 06-26-14
Location: DFW/29Palms
Default Can someone look over my math?

Thanks in advance for any constructive criticism! I am starting a build on a 110GA propane tank.

CC volume = 25410 cu. in. actual
FB volume = 8470 cu. in. recommended

Chimney volume = .05 x 9680 = 484 cu. in. ( 4" ID stack X 38" tall above the CC )

FB to CC recommended opening = .008 X 9680 = 78 Sq. in. ( 12" r x 5.5" height )

RF plate area 78 X 1.5 = 116 sq. in. ( 12" r x 7.25" height )

Mankussm is offline   Reply With Quote




Old 07-05-2014, 11:00 PM   #2
Mankussm
Found some matches.
 
Join Date: 06-26-14
Location: DFW/29Palms
Default

Man, 77 views and no help!?!
Mankussm is offline   Reply With Quote


Old 07-05-2014, 11:04 PM   #3
plowin-fire
Full Fledged Farker
 
Join Date: 04-26-11
Location: Beresford, SD
Default

I dont have a clue on the design and numbers end of it but looks like you figured it out. Just build it and smoke it up!
__________________
B & T's BBQ Catering and Vending
plowin-fire is offline   Reply With Quote


Old 07-05-2014, 11:05 PM   #4
mikemci
Babbling Farker
 
Join Date: 04-19-13
Location: Live Oak, Texas
Default

Is this derived from a smoker calculator?
__________________
55 gal.UDS
stick burner
mini WSM
red Thermapen


There are two kinds of countries in the world, those that use the metric system and the one that sent men to the moon and back.
mikemci is offline   Reply With Quote


Old 07-05-2014, 11:09 PM   #5
Mankussm
Found some matches.
 
Join Date: 06-26-14
Location: DFW/29Palms
Default

Quote:
Originally Posted by mikemci View Post
Is this derived from a smoker calculator?
The numbers were, but not the cut out for the tank. I am asking if the numbers jive with my layout. Thanks in advance.

http://www.feldoncentral.com/bbqcalculator.html
Mankussm is offline   Reply With Quote


Old 07-05-2014, 11:17 PM   #6
mikemci
Babbling Farker
 
Join Date: 04-19-13
Location: Live Oak, Texas
Default

I don't know the formula for calculating the area of a partial circle like that. What I did on my cut out was to draw a 1" square grid pattern on a piece of paper, then drew the radius of the bottom of my CC, then counted the number of squares to match what Feldons said I needed. Hope this helps, it's all my simple mind could figure.
__________________
55 gal.UDS
stick burner
mini WSM
red Thermapen


There are two kinds of countries in the world, those that use the metric system and the one that sent men to the moon and back.
mikemci is offline   Reply With Quote


Old 07-05-2014, 11:25 PM   #7
Mankussm
Found some matches.
 
Join Date: 06-26-14
Location: DFW/29Palms
Default

Quote:
Originally Posted by mikemci View Post
I don't know the formula for calculating the area of a partial circle like that. What I did on my cut out was to draw a 1" square grid pattern on a piece of paper, then drew the radius of the bottom of my CC, then counted the number of squares to match what Feldons said I needed. Hope this helps, it's all my simple mind could figure.

Thats a good idea. Thanks!
Mankussm is offline   Reply With Quote


Old 07-05-2014, 11:29 PM   #8
mikemci
Babbling Farker
 
Join Date: 04-19-13
Location: Live Oak, Texas
Default

It worked for me. I tried looking up online how to do it mathematically and it was way over this country boy's head.
__________________
55 gal.UDS
stick burner
mini WSM
red Thermapen


There are two kinds of countries in the world, those that use the metric system and the one that sent men to the moon and back.
mikemci is offline   Reply With Quote


Old 07-06-2014, 06:08 AM   #9
buttburnersbbq
Full Fledged Farker
 
Join Date: 03-19-12
Location: waxhaw,nc
Default

All your calculations match the pit calculator. The only thing is the reverse flow plate should be even with the firebox. I would raise the fire box to height of RF plate. I built my RF smoker 1 1/2 years ago out of a 250 gallon tank. I used the same pit calculator. Everything came out and works great . I put a rack in the fire box at 4" high. I have my intakes under the rack. So air goes through the fire . I believe it gives you a better burning fire. Also it is always better to go bigger with your openings . I have adjustable vents on my intakes and leave the exhaust wide open. Control temp by intakes. Remember it is all about the draft. If you can not get the right draft the pit will not get up to temp. Also I made the mistake to take my exhaust to my first grate level. Bad idea , I had to cut it off to the top of the tank. From top rack to bottom rack I had a 70 degree difference. Once I cut it off , I am not more than 10 degrees. Here is a link to my build video.
__________________
2- 22.5 WSM , 150 Gallon Offset , 250 Gallon Reverse Flow
buttburnersbbq is offline   Reply With Quote


Thanks from:--->
Old 07-06-2014, 09:08 AM   #10
Mankussm
Found some matches.
 
Join Date: 06-26-14
Location: DFW/29Palms
Default

Quote:
Originally Posted by buttburnersbbq View Post
All your calculations match the pit calculator. The only thing is the reverse flow plate should be even with the firebox. I would raise the fire box to height of RF plate. I built my RF smoker 1 1/2 years ago out of a 250 gallon tank. I used the same pit calculator. Everything came out and works great . I put a rack in the fire box at 4" high. I have my intakes under the rack. So air goes through the fire . I believe it gives you a better burning fire. Also it is always better to go bigger with your openings . I have adjustable vents on my intakes and leave the exhaust wide open. Control temp by intakes. Remember it is all about the draft. If you can not get the right draft the pit will not get up to temp. Also I made the mistake to take my exhaust to my first grate level. Bad idea , I had to cut it off to the top of the tank. From top rack to bottom rack I had a 70 degree difference. Once I cut it off , I am not more than 10 degrees. Here is a link to my build video. My First Smoker Build - YouTube
The main reason I wanted the reverse plate above the FB was to prevent a hot spot on that side. All else looks great. Thanks for the advise.
Mankussm is offline   Reply With Quote


Old 07-06-2014, 11:46 AM   #11
mikemci
Babbling Farker
 
Join Date: 04-19-13
Location: Live Oak, Texas
Default

Nice build buttburner! Enjoyed the video. One question re: smokestack location, is there a reason behind your decision not to center it on the c.c.?
__________________
55 gal.UDS
stick burner
mini WSM
red Thermapen


There are two kinds of countries in the world, those that use the metric system and the one that sent men to the moon and back.
mikemci is offline   Reply With Quote


Old 07-06-2014, 12:24 PM   #12
QDoc
is one Smokin' Farker
 
QDoc's Avatar
 
Join Date: 03-02-07
Location: Pine Bluff, Arkansas
Default

One thing to consider is the ultimate temp you wish the cooker to achieve.
Most cookers are designed to cook at around 250. That's where my lang 84 is happy.
If I were to remodel it I would increase the firebox size by maybe 50% and place the door on the side so the intake vents could be located in the back like a Geer. Also I would place two 6 inch vent stacks and make the intake vents 100% larger. Ben Lang advises cracking the cooking chamber doors and opening the firebox door to get to 300. Many people are cooking higher than in the past and I would like for my lang to do so. I am seriously considering a redesign.
QDoc is offline   Reply With Quote


Old 07-06-2014, 01:19 PM   #13
buttburnersbbq
Full Fledged Farker
 
Join Date: 03-19-12
Location: waxhaw,nc
Default

Quote:
Originally Posted by mikemci View Post
Nice build buttburner! Enjoyed the video. One question re: smokestack location, is there a reason behind your decision not to center it on the c.c.?
I off centered stack due to I left the original hooks on tank so I could lift and put on my trailer. It is not that far off center and I have no issues.
__________________
2- 22.5 WSM , 150 Gallon Offset , 250 Gallon Reverse Flow
buttburnersbbq is offline   Reply With Quote


Thanks from:--->
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


Forum Custom Search: Enter your Search text below. GOOGLE will search ONLY the BBQ Brethren Forum.
Custom search MAY not work(no display box) in some configurations of Internet Explorer. Please use compliant version of Firefox or Chrome.







All times are GMT -5. The time now is 04:08 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
2003 -2012 © BBQ-Brethren Inc. All rights reserved. All Content and Flaming Pig Logo are registered and protected under U.S and International Copyright and Trademarks. Content Within this Website Is Property of BBQ Brethren Inc. Reproduction or alteration is strictly prohibited.
no new posts