Using propane tank as base for bbq project

Discussion in 'Wood Smokers' started by smokinjunkie, Jul 19, 2009.

  1. smokinjunkie

    smokinjunkie Newbie

    Hi i was curious if any one has, and can tell me how to clean a propane tank to use it as a main chamber for a bbq smoker. I am a welder and fabricator at heart and getting into smoking more and more over the last ten years, but this is above my ability as far as knowing what the nasty garlic smell from a propane tank would do to your meat. I have heard of people doing it but what they did is unknown. I have a very large 24" by 48" tank that was on my property when i moved here. Any help would be appreciated. [​IMG]
  2. hoser

    hoser Smoking Fanatic SMF Premier Member

    I don't have a clue personally, but there are lots of great fabricators that are around here.
    I'm sure someone who knows will be around shortly....good luck with your build!
  3. bbq engineer

    bbq engineer Master of the Pit OTBS Member SMF Premier Member

    Hey Junkie,

    The smell comes from Methanethiol (also known as methyl mercaptan) which is added to the propane (which is odorless). This compound is added as a safety measure so that leaks can be easily noted. It vaporizes easily, but is added at the refinery as a liquid to liquid propane. When the propane vaporizes, however, since the boiling point of the odorant is different than the propane (liquid to gas conversion) some of the methyl mercaptan will remain in the tank, and the concentration will increase. Even when the tank is evacuated, the characteristic smell will remain, ultimately coating the inside of the tank surface.

    I have seen in posts that the process for decomissioning a tank in preparation for BBQ include filling the tank with water and detergent and letting it slosh around in the back of a truck or a trailer for a while, pressure washing the heck out of it, and lighting roaring fires in the completely evacuated tank to burn them clean. If it were me, I would do all of that at a minimum, or start with a bare pipe or water pressure tank. You may check out the "wood smoker" section for what others have is one pretty informative post by Uncle Beef...

    What ever you do, please be safe with evacuating and cutting on a propane tank, and ensure that your insurance is up to date before you begin. Also, remember that propane is heavier than air, so an uncapped tank could potentially have a pool of propane sitting in the bottom of it. in this case, the confined space will make a most excellent bomb, so be careful and good luck!
  4. travcoman45

    travcoman45 Master of the Pit OTBS Member

    One way is fillin it bout 1/3 rd full a water an soap an givin it a ride, ya wanna do that two er three times.

    Another is ta fill it bout 1/2 full a hot soapy water an stuff an air hose in there an let it bubble away. I'd do this two er three times to.

    Before ya cut that tank ya should fill it with either nitrogen, co2 er ya can hook it upta the exhaust on yer truck an let it fill with inert gas, let that stuff run while yer cuttin it. I'd cut with a angle grinder with the thin cuttin blade.

    The first cut is the most nerve rackin. Best to let them sit with all bungs out an some air movement fer as long as ya can, get the lp outa there.

    If after all the soap an cuttin an weldin the tank still smells, ya can try a vinegar bath to see ifin that will hep some to.

    Good luck.
  5. hemi

    hemi Smoking Fanatic

    This is my thing.. welder/machinist/ mechanic in a forklift shop..
    The way that works for me is to remove one of the larger plugs
    or bungs and prop/ rotate the tank until the opening is at the highest
    point and fill it with water. jog or roll or jiggle the tank to make SURE
    alla the air is out.[fumes] do this al least twice. lay it down in the position that U want and fill it one more time. fill it as far as possible.
    I leave it about a half inch low on water and light a torch and stick it in
    the hole.

    Now before U start downrating my ansestors, think about it.. If You
    have filled it with water a few times it means that U have pushed ALL
    the fumes out with water . If it is fulla water, it CAN'T be fulla fumes.
    The reason that I fill it with water except for a half inch or so at the top
    and stick a lighter or torch inna hole is because it makes you a WHOLE
    lot more comfortable with it. Decreases yer pucker power a BUNCH..
    The worse I have ever had happen is the time I probably got a bit lax about making sure it was FULL of water a coupla times. It flashed over
    and just about gave me the green apple quick step. But being full
    of water except a half inch and the plug out it just went ''Whoosh''
    and it was gone. It just made me more careful next time.
    Nitrogen as a flush works well also. Don't try the exhaust trick
    because of the danger of unburnt fuel. always cut it as full of water
    as possible.

    This is the way I cut the lp tanks at work for disposal because
    the scrap yard will not accept them unless they are cut. If you don't
    want to take a chance on cutting it yerself, it just means yer normal..

    [​IMG] Hemi
  6. rio_grande

    rio_grande Smoking Fanatic

    All are good recomendations. We used Co2 alone for evacuating gas tanks for years. I have on occasion cut into them and found gas still in the bottom. Guess it did not blow because no o2 was availble,,, So I would also recomend washing it out with the detergent and water. Not like it is gonna hurt anything and may save your life... But this is nothing to be afraid of,,, just respected.

    I am getting ready to do a similar build but got lucky and scored 2 new never used tanks,,,, better believe I will still wash it out just to be safe !!
  7. smokinjunkie

    smokinjunkie Newbie

    Hey everybody, thanks for all the good ideas. The one thing i still dont know about is the odor it may leave behind and if i will notice it in the meats. Maybe rub it with a bunch of bacon grease or something and light a big ol fire in there. I will figure it out im sure. thanks everybody for all the help.
  8. bbq engineer

    bbq engineer Master of the Pit OTBS Member SMF Premier Member

    I think there have been more smokers made out of old propane tanks than probably anything else. I guarantee they wouldn't be so common if they left even a trace of that smell in the meat! I bet a big ole fire will take care of that in short order. Just my $.02.
  9. mgnorcal

    mgnorcal Meat Mopper SMF Premier Member

    Based on the physical properties of the substance, high heat alone should clear out any residue.

    Never heard or read of anyone having a problem with the smell in one of these units.

    BOILING POINT: 43 F (6 C)
  10. unclebeef

    unclebeef Fire Starter

    hey UNCLCEBEEF here, just my opinion, fill with water to push out any propane that's left and cut.make sure the water is pushing out at the highest point,this is very important to make sure all propane is pushed out .so far i've done three this way and HAVE NOT had any flames or flaming liquid blowing in my face.some people here seem to short cut in this step and have had some excitement!

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