# 1st smoker build



## lpbg (Jun 19, 2017)

​Im going to be making my first smoker trailer with this old propane tank not sure the exact size guessing 120 gallon and a 16ft trailer I do have a few questions on some things before i get started ...i will be making it into a RF smoker and one question is what thickness should i use for the firebox and also the size i should use for the RF plate on the inside...and as far as the trailer what kind of floor would be good to go with ...i also have aquired a 3 bay stainless steel sink its about the trailer (6ft)...tyi 













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__ lpbg
__ Jun 11, 2017


















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__ lpbg
__ Jun 11, 2017


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## ahumadora (Jun 22, 2017)

Looks closer to 200 gallons.     pass the dimensions.

Use these calculations for a great working smoker.    http://www.smokingmeatforums.com/a/reverse-flow-smoker-how-to-calculate-build-tutorial

Don't be afraid to ask questions BEFORE you start chopping it apart


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## kam59 (Jun 22, 2017)

Congratulations on your tank find. :)

A 120 will be around 24" 68"

A 150 gall will be around 25" x 84"

A 250 gallon will be around 30" x 93"

For your Reverse flow plate I recommend 1/4" plate.

For your firebox I would also recommend 1/4" minimum.

For easy calculations that work you can use the Pit calculator it has built many reverse flow cookers that work just keep your firebox to within 120% and your'e golden. My email is also attached to it for any questions you may have

http://www.feldoncentral.com/bbqcalculator.html

Also here is a handy calculator for figuring your firebox to cooking chamber opening.

http://planetcalc.com/search/?tag=3128


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## daveomak (Jun 24, 2017)

Ahumadora said:


> Looks closer to 200 gallons.     pass the dimensions.
> 
> Use these calculations for a great working smoker.    http://www.smokingmeatforums.com/a/reverse-flow-smoker-how-to-calculate-build-tutorial
> 
> Don't be afraid to ask questions BEFORE you start chopping it apart










   ....  Ahumadora has you covered with great advice....   BTW...   ALL questions are great questions....


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## lpbg (Jun 24, 2017)

I appreciate pointing me in the right direction guys...i didn't get any measurements on it yet but your right the more I look at different tanks this one is definitely looking bigger than 120. I'm thinking about it a lot I don't wanna screw it up lol so I'm doing a lot of research before I even cut it open. Read about the water and dish soap ...one of the valves is off of there and I'm guessing it's been that way for a while so I'm going to just fill it up and let the water run out of the top of the open valve for a while and let it sit for a few days and I should be good to cut it open(hopefully)? Think I'm gonna have 2 doors on it ...and I thought about cutting the Firebox side so that it's flat but not sure it seems like it would be easier if it was flush with the FB ...and depending on how much I cut off I wouldn't loose to much cooking space what's your thoughts


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## kam59 (Jun 24, 2017)

If your'e not planing on a warmer then just cutting into the dome is a good option because it saves a piece of plate. If you ever plan on adding a warmer cutting off the dome now is a good option plus you are correct the fit up is a lot easier.


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## daveomak (Jun 24, 2017)

This picture is of the inside of a propane tank and the weld seam on the dome end...    Build the correct size FB and make it 1" wider than the propane tank...   cut the tank notch out 3/4" taller than the suggested opening size for the FB/CC opening....  Slide the FB into the notch and tack weld from the outside to stabilize the tank and FB...   THEN cut the door...  The FB tack welded in place will help to stop the metal from moving when cut...   (or so it says in fine print)   After the door cut is removed, weld the FB from the inside  and then cut out the opening...  At that time, you can leave some metal on the bottom of the cut out opening for a grease dam that will stop stuff from dripping into the FB and causing one huge fire....

Then the RF plate can be welded to the top of the FB and the weld seam will not interfere with the fit up... 













Propane Tank weld joint INSIDE.jpg



__ daveomak
__ Jun 24, 2017


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## ahumadora (Jun 24, 2017)

IPBG,

Treat the propane tank like you would a girl.

Give it the sniff test before you go in!!

Poke your nose in the opening and if there is a strong odor of gas do the water/dish wash  if none, hit it!

For most newbies reading this forum who are building at home I would recommend using a grinder with cutoff wheel to do the door cut outs. (most tanks are max 1/4")

you should be able to score a 9" or 7" grinder cheap in the USA and use a few cutoff discs.  (9" grinders are for men, so give them the respect they deserve, I have smashed some of my teeth when they have kicked back!)    

For a nasty old tank like you have above use a wire wheel on the grinder. ( much easier to do the entire tank now BEFORE you cut into it to clean it up.)

Then use a flexible steel ruler to measure down from 12 o'clock.  For a tank that diameter I would probably make the top cut about 6" (150mm) down from 12 o'clock.   bottom cut about 3" below 3 o'clock.  You can wrap a tape around the circumference to divide it into quarters.

Mark it with a scribe or fine tip marker ( don't use a melted old crayon or blunt marker pen.)   For the sides of the door stay about 1 1/2' (35mm away from the weld so as not to hit the internal ring.

If you have a plasma cutter you can use that if you have a new electrode.    Don't use a gas torch to cut out the doors, that's just hack!  I don't care how good you are with a gas torch, you can't come close to the presicion of a cutting  wheel.    Take you time and make everything perfectly straight and square.

To block all the openings on the top cut the minimum posible to remove the threaded bung. It is much easier to cut square holes and filll them.    You can use 3/16 or 1/4" plate to fill them. Tack weld one side in then tap it down until it is flush and work your way across to the other side.   You can tack weld on a piece of scrap to the tab to stop it falling in, then cut it off after.

As I said before.

Post it here and the kind folk here can help you with it.     20 mins on the computer beats grinding off a F%$&^ up door or firebox.


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## kam59 (Jun 24, 2017)

If you are handy with a torch you will have no problems. Use a Victor 0-1-101 or equivalent tip it will leave you with about a 1/32" kerf which is really tight.


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## lpbg (Jul 17, 2017)

20170717_132036.jpg



__ lpbg
__ Jul 17, 2017






Started grinding the old paint off with a angle grinder with a wire brush attachment worked on it for about an hour or so and got maybes quarter of it done...never noticed this tag on here so I guess it's a 124 gallon tank from 1975 when I measured it was 70"x 25" and was wondering what size it actually was


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## lpbg (Jul 17, 2017)

Screenshot_20170717-215203.png



__ lpbg
__ Jul 17, 2017






Nice 3 bay sink I got too I'm wondering about different ways to utilize it ...ive seen on other trailer builds they use holding tanks and pumps from an rv which is the route I'm thinking of taking any other ideas lmk thanks [emoji]128526[/emoji]


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## lpbg (Jul 17, 2017)

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__ lpbg
__ Jul 17, 2017


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## kam59 (Jul 17, 2017)

lpbg said:


> 20170717_132036.jpg
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## lpbg (Jul 18, 2017)

Ya man I figured it had to be close to 120 when I measured it and saw the dimensions you posted before appreciate all the helpful info


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## kam59 (Jul 18, 2017)

You are very welcome glad to help. :)


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## lpbg (Jan 11, 2018)

I'm gonna end up making this one a reverse flow with the warmer box on top of the FB. My question is what thickness should I make the FB and the warmer and also the plate that ill need after i cut one of the dome ends off my guess is 1/4". Also what's a good size for the warmer box . Oh and should I insulate the FB and if so what should it be it be insulated with


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