# 120 gallon smoker build

Discussion in 'Reverse Flow' started by hachmeister, Mar 5, 2016.

1. ### hachmeisterNewbie

well im getting ready to start my long awaited reverse flow smoker. im having a bit of trouble with Dave O's formula. the tag on the propane tank reads 124 gallon water capacity. outside diameter of 24 and overall length of 70. when i calculate the tank volume in cubic inches i get 28,644. when i figure CC volume i get 30,361. how can the CC be bigger than the tank volume? all help is appreciated!

2. ### nwbhossSmoking Fanatic

You are going to get a slight difference going from figuring gallons to measuring the tank size to get the volume. The rounded ends make an exact measurement pretty tough. I have been giving myself headaches for days trying to understand all the numbers. Your numbers between the two ways of calculating are not that far off and from what I understand the tags on the tanks can allow for expansion so that number may be a little less. You will be close either way so maybe split the difference and go with it?

I am new at this as well so please dont take my word as gospel.

One word of advise is PLAN PLAN PLAN!! I wish I had been more thorough when I first started my smoker and done the math before beginning I would have saved myself a lot of work.

3. ### mp4sFire Starter

There a website that has a bell end calculator that will help. I'll try to dig it up when I get back to my computer.

4. ### imafishingfredSmoke Blower

Easy way is to measure tank from end to end . Then measure from weld seam to weld seam . Subtract weld to weld from overall tank. Divide the difference by 1/2 and add the result back to the weld to weld length. This is the tank length you want to use.

If you look at the sketch, you want 1 end and the center added together. Use the diameter from the center of the tank.

6. ### hachmeisterNewbie

Thanks for all the help guys. I appreciate it. I got the FB/CC hole cut today now just to get it burned out and start building the rest! I will get pictures as soon as I can.

8. ### mp4sFire Starter

Basically - compare the different shapes in the chart to yours. Mine was Standard Flange. I see a lot of propane tanks that look to be Hemispherical.

9. ### hachmeisterNewbie

thank you for all the help guys. i have got the opening cut for the fire box and will soon be building the firebox and attaching it and then cutting the door. my next question is how am i suppose to figure the area at the end of the RF plate. i plan to just go level with the RF plate at the top of the fire box. the segment height for my FB/CC is 8. can i just stop the RF plate 8 inches from the end of the tank?

10. ### hachmeisterNewbie

Well after waiting for metal to come in and time me and my brother are getting this thing rolling and i finally have a few pictures!

I am a mechanic and thought a couple connecting rods would make a good handle
and heres the firebox mounted and legs on the smoker.

the top cut of the door is done and hinges on. will be getting more pictures this week and should have it finished up this week

martyinco likes this.
11. ### martyincoNewbie

I dig the handles!

12. ### hachmeisterNewbie

few more pictures of the build should be finished up tomorrow except for paint

torque wrench for a handle

how we got the spacing for the cook chamber racks

grate for the firebox

13. ### aussiebazzaSmoke Blower

You're smashing it out quick. Well done as it looks awesome!

14. ### essexsmokerSmoke Blower

Great looking smoker!

I have a cylinder the same size and another one slightly smaller going at work. I'd love to do this but just don't have the time or room. 😢

I keep looking at it and thinking, well if just take it home and store it... one day... lol.

15. ### hachmeisterNewbie

the smoker is all done and ready for paint. just have to knock off the last two original tank legs and clean it up

16. ### hachmeisterNewbie

well the smoker is home and in its final place now just to paint it and get the latches on and season it. hopefully get it painted this weekend

Love it!

18. ### aussiebazzaSmoke Blower

Really nice work!

Quick question, how much room did you leave between your BP and your first rack?

Bazza

19. ### hachmeisterNewbie

There is just over 3 1/2 inches from the reverse flow plate to the first rack.

20. ### snookdawgNewbie

Im very interested to see how this thing performs.  This is the exact size and style that Im planning on building in the next few months.  Great build by the way it looks amazing.