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Tank tumbling process

Discussion in 'Do It Yourself - DIY' started by BigRed96, Aug 16, 2020.

  1. BigRed96

    BigRed96 Contributor

    # of Dives: 100 - 199
    Location: New Richmond, Oh
    251
    141
    Good Day All, I was wondering what your process was from tumbling to LDS in order to prevent tanks from rusting before the shop does a visual?
    I just built a tumbler to tumble my own tanks as the LDS wanted $25 a piece to tumble them. Add that to a viz and a hydro and it gets a bit pricey. Anyway, how long do you typically have after tumbling to get the bottles to the LDS before re-rusting or flash rusting occurs? I want to make sure I don’t get charged $25 for tumbling after
    I tumbled them on my own.
     
  2. runsongas

    runsongas Contributor

    # of Dives: 500 - 999
    Location: California - Bay Area
    4,622
    2,214
    if you dry rinse and dry the tanks correctly after tumbling, you should have no flash rusting. but for the amount of work it is, 25 dollars is pretty reasonable. another option is to find a hydro facility and get them to shot blast the tanks.
     
  3. zider

    zider Solo Diver

    # of Dives: 200 - 499
    Location: Brownsburg, IN
    402
    74
    I’ve been using the Global rust inhibitor for years and it works great. You just pour about one liter of the diluted solution into the tank, put it on the tumbler for a few minutes to disperse, dump, and blow dry with tank air. Works like a charm. I know a lot of folks say it’s not necessary and you can get the same results with a hot water rinse before drying. I always still had light flash rust with the hot water method. For me, the rust inhibitor has given great results and has made the job much easier.

    Compound O - Oxygen Safe Rust Inhibitor - Gallon

    Compound O - Oxygen Safe Rust Inhibitor - 16 Ounces
     
  4. BigRed96

    BigRed96 Contributor

    # of Dives: 100 - 199
    Location: New Richmond, Oh
    251
    141
    I’m assuming you just mix it up and pour some into the tank, swish it around, and dump it out? Can you retain the used portion for reuse? Would this inhibit the rust indefinitely or at least long enough for me to get the bottles to my lds for viz and hydro?
     
  5. Jack Hammer

    Jack Hammer Solo Diver

    2,216
    1,666
    I use about a capful or two of rust inhibitor and tap water with the appropriate media when tumbling. Rinse immediately with regular water and immediately dry with either air from a scuba tank or put it on a drying rack with mildly warm air. No rusting or flash rust. Tanks look brand new. Put a valve on it when done, it should still look new when they vis it.
     
    BigRed96 likes this.
  6. zider

    zider Solo Diver

    # of Dives: 200 - 499
    Location: Brownsburg, IN
    402
    74
    That’s the basic process. The official instructions say to put it back on the tumbler to rinse the solution around the tank. I see no reason you couldn’t do it by hand, but HP130s are heavy so I use the tumbler.:wink: As far as I am aware, the diluted mix is one time use. 1oz of concentrate makes enough for 3 big steel tanks so I wouldn’t worry about the waste. I’ve not let a tank sit after treatment for more than an hour so I can’t say how long it would hold the rust off. My guess is quite a while if you blow some clean/dry gas in from another tank and seal it with a plug. No moisture means no rust. I inspect my own tanks so after drying they get examined and then put under pressure.
     
    BigRed96 likes this.
  7. Jack Hammer

    Jack Hammer Solo Diver

    2,216
    1,666
    To be clear, I add a tiny amount (a capful on small tanks, 2 on larger) of rust inhibitor with the media and the water. The media gets saved and reused. The inhibitor drains away with the water. No need for any afterwards. A gallon should last a long time.
     
    grantctobin, rjack321 and BigRed96 like this.
  8. whitefang21

    whitefang21 Divemaster

    # of Dives: 200 - 499
    Location: New jersey
    205
    19
    have any tried blue gold and what are the results in regards to being a rust inhibitor and to prevent flash rust.
     
  9. Anthony in NC

    Anthony in NC Registered

    # of Dives: 200 - 499
    Location: NotYourBusiness
    32
    59
    I normally tumble dry, then rinse with 90% alcohol. The alcohol flash dries pretty fast, unlike a simple water rinse. Then invert the cylinder on the warm air dryer. It'll dry within 4 -5 minutes. The drawback of using alcohol is it obviously costs a few bucks more than water, and it requires venting, else the next air fill will taste like alcohol. Vent it by leaving it on the dryer for 10 minutes to blow out all the alcohol fumes.

    I use the 90% alcohol that you find in CVS or medical supply stores. I'm told the 70% you find at WalMart, etc. leaves a carcinogen when it dries that the 90% doesn't.

    Of course, you can just rinse with water, but you need a warm-air dryer else you'll get flash rust.
    I made my dryer out of an old condemned scuba cylinder, a hot air gun, and some copper fittings. The only cost was the hot air gun (that I use in the shop for other things anyway) and a few bucks for the copper fittings. Dryer.jpg

    Never had a case of seeing rust in steel tanks I do that way on the next years visual. Use lead-free solder.
     
  10. -JD-

    -JD- Eclecticist ScubaBoard Supporter

    # of Dives: 50 - 99
    Location: Greater Philadelphia, PA
    1,081
    757
    Is that a 6" PVC Pipe coupling as a stand?

    FWIW, I cant imagine that lead is any issue in this application. In plumbing it is really only an issue with lengthy contact with (typically unusually acidic) water.
     
    Anthony in NC likes this.

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