# 600 Gal RF build

#### dkmiller16

##### Fire Starter
Just picked up this 600 gallon tank and trailer. Looking to do an insulated firebox with a warming box on top of the firebox. Tank is 106" long and 42" diameter. Appreciate all the help and knowledge you guys share on this forum.

#### fivetricks

##### Master of the Pit
OTBS Member
Why choose such a small tank? Not going to able to do much more than a couple of grilled cheese sandwiches on that tiny thing.

:-D

Looks great. Will be watching.

#### AllTuckerdOut

##### Smoke Blower
I have to agree with fivetricks , you may want to see if you can find a bigger tank ;)

#### dkmiller16

##### Fire Starter
Using the build tutorial that is posted in this forum, I cheated and used all the calculations/formulas to create an excel sheet to enter my tank dimensions and excel does all the work. This is what I came up with. daveomak do these numbers look close? I know you mentioned in the build tutorial that wide/fat with a shorter cc can equate to smaller numbers. Any suggestions or changes you would have. Thanks

Tank Dimension
Length 106
Diameter (ID) 41
Volume Gallons 606
Volume Cubic Inches 139,947

FB/CC Opening-sq in 560
Area under RF plate-sq in 560
Area required at end of RF Plate-sq in 560
Minimum Volume Firebox-Cubic in 46,183
Firebox Air Inlet-sq in 140
Upper Air Inlet-sq in 28
Lower Air Inlet-sq in 112

Exhaust Stack Volume above CC-Cubic in 3,079

Firebox Volume 46,656
Length 36
Width 36
Height 36

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#### AllTuckerdOut

##### Smoke Blower
dkmiller16 if you are looking for calculations, you can follow daveomak's tutorial.

I created a calculator site that does part of it for you, up to where you have to calculate the opening. Once you get up to that part, you're going to have to follow the part in daveomaks starting at "This circle calculator is really cool... It does it all.... Just fill in the necessary blanks..."

I just got done with a 500 gallon reverse flow, you can see here. I followed daveomak's tutorial and everything flows great, fire is super easy to keep and smoke is great! If you have any sort of questions feel free to ask, everyone has been super helpful here!

#### dkmiller16

##### Fire Starter
Thanks AllTuckerdOut I actually have a post waiting for approval that I did all the calculations using daveomak's tutorial.

#### daveomak

##### SMF Hall of Fame Pitmaster
OTBS Member
SMF Premier Member
Quote from the build tutorial... Wide/Fat Short CC may use smaller numbers due to reduced surface area friction to volume..
Adjusting to smaller areas would be FB/CC opening, Area under the RF plate... maybe by 10% if it is a MUST DO...

Using the build tutorial that is posted in this forum, I cheated and used all the calculations/formulas to create an excel sheet to enter my tank dimensions and excel does all the work. This is what I came up with. daveomak do these numbers look close? I know you mentioned in the build tutorial that wide/fat with a shorter cc can equate to smaller numbers. Any suggestions or changes you would have. Thanks

Tank Dimension
Length 106
Diameter (ID) 41
Volume Gallons 606
Volume Cubic Inches 139,947

FB/CC Opening-sq in 560
Area under RF plate-sq in 560
Area required at end of RF Plate-sq in 560
Minimum Volume Firebox-Cubic in 46,183
Firebox Air Inlet-sq in 140
Upper Air Inlet-sq in 28
Lower Air Inlet-sq in 112

Exhaust Stack Volume above CC-Cubic in 3,079

Firebox Volume 46,656
Length 36
Width 36
Height 36

#### dkmiller16

##### Fire Starter
Quote from the build tutorial... Wide/Fat Short CC may use smaller numbers due to reduced surface area friction to volume..
Adjusting to smaller areas would be FB/CC opening, Area under the RF plate... maybe by 10% if it is a MUST DO...
Not a "must do", was more looking at it as, will it change performance. I am planning on sliding the fb into the cc, maybe a couple inches past the bell.

#### daveomak

##### SMF Hall of Fame Pitmaster
OTBS Member
SMF Premier Member
Slide it in past the weld for a much easier fit up... The then all the tuning plate will be one length... Make all the plates length the same as the width of the FB inside the CC where you welded it up.. then you will not have any obstructions to the air flow.... Deflector plates do nothing but restrict air flow...

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#### dkmiller16

##### Fire Starter
So I have been crunching some numbers and looking at the FB/CC opening. I used the circle calculator and came up with a "segment height" of 17.5" and "chord AB" of 40.559". This means that the RF plate will essentially be placed just below
the center point of the tank. Is that correct or am I missing something. I attached the screenshot of the circle calculation. Once I open up the tank I will get an exact radius but I feel like I am really close.

#### daveomak

##### SMF Hall of Fame Pitmaster
OTBS Member
SMF Premier Member
Due to the wide diameter of the tank, you can lower the ED height a couple inches.. A tank of those dimensions has a good volume to surface area and there is very little friction introduced...
That's the same tank I have.... Be sure to cut into the tank PAST the welds for inserting the FB... that will make fit up easier...

#### dkmiller16

##### Fire Starter
Due to the wide diameter of the tank, you can lower the ED height a couple inches.. A tank of those dimensions has a good volume to surface area and there is very little friction introduced...
That's the same tank I have.... Be sure to cut into the tank PAST the welds for inserting the FB... that will make fit up easier...
Thanks daveomak , I will lower the ED height a bit and will def slide the FB in past the weld. Do you happen to have any pics of your smoker. I am thinking a single door and trying to stack 3 shelves in this one.

#### AllTuckerdOut

##### Smoke Blower
dkmiller16 I would definitely suggest 2 doors. A single door on that big of a tank is going to be extremely heavy. You could counterweight it to make it lighter. But, personally I like the 2 door approach especially if I am doing different meats.

#### dkmiller16

##### Fire Starter
I was going back and forth on that AllTuckerdOut , I have 63" between the bells. I was hoping to have a big enough door and rack to do a whole hog. My concern was if I split that into 2 doors I will only have 30" opening. I am not familiar with what size a whole hog takes but thought i might need more room then that. I guess I could with 2 different size doors.

Does anyone do whole hog on a rf and if so what kind of room should I have?

#### daveomak

##### SMF Hall of Fame Pitmaster
OTBS Member
SMF Premier Member
With a smoker that wide, I would put doors on both sides...

#### daveomak

##### SMF Hall of Fame Pitmaster
OTBS Member
SMF Premier Member
It still has propane in it... I a year or so, it will be empty.....

##### Smoking Fanatic
Glad to see you covering all bases, but ask yourself how often to you do a whole hog? We do one every once in a while....60-80 pounder fits fine in a 48" RF. Or do what Dave recommends build a pit out of cinder block.

Good luck, watching now

RG

#### dkmiller16

##### Fire Starter
Glad to see you covering all bases, but ask yourself how often to you do a whole hog? We do one every once in a while....60-80 pounder fits fine in a 48" RF. Or do what Dave recommends build a pit out of cinder block.

Good luck, watching now

RG

View attachment 401871
Excellent point. I was thinking of all the ways I could use this RF but it wouldn't be very often that I would do a whole hog.

#### starwoods

##### Newbie
This will be a huge project! You may want to re-think your trailer options. The reverse flow I just built from a 500 gal propane tank was extremely heavy due to the 3/8" inch thick metal. I would make sure that you have a heavy duty axle, 3500 lbs or better. Good luck!