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Should I buy an old Aluminum 80?

Discussion in 'Tanks, Valves and Bands' started by DanSinks, Apr 11, 2019.

  1. DanSinks

    DanSinks Nassau Grouper

    # of Dives: 100 - 199
    Location: Massachusetts
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    I want to buy an old Sherwood aluminum 80 manufactured in 1995 because I want to have 2, it's yellow and will match my other old Sherwood tank from the same decade. I want the bright yellow so my black lobster permit numbers will stand out. The person selling it is almost giving it away. But it needs a hydro and VIP. If I buy it then I'll end up selling my newer aluminum 80 from 2014 that has brushed aluminum finish(and will need a hydro this year).

    I know dive shops won't touch my older aluminum tanks from the 1980's, due to a batch of bad alloy metal back then I guess, but no dive shop has questioned my Sherwood.

    Are aluminum tanks from the 1990's ok or are they also destined to be considered unsafe at some point?
     
  2. runsongas

    runsongas Great White

    # of Dives: 500 - 999
    Location: California - Bay Area
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    1995 is 6061 alloy, just make sure the shop you use doesn't go strictly by age though.

    for MA and lobstering, i would look into steel tanks. hp120s are pretty popular for bug hunting in socal.
     
    DanSinks likes this.
  3. CT-Rich

    CT-Rich Solo Diver

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    You might want to take a pass on a tank that old. It would probably be fine, but you may go into a shop where the tank monkey was told not fill pre-2000 tanks. Plenty of newer AL tanks around, cheap with fewer hasssles. A friend retired a couple tanks because agism. I wouldn’t buy an old tank to sell a new tank.

    I would look for a match to your 2014 tank. You migt look at going steel, they trim better and offset some of your lead needs, which is good in cold water diving.
     
    tmassey and DanSinks like this.
  4. DanSinks

    DanSinks Nassau Grouper

    # of Dives: 100 - 199
    Location: Massachusetts
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    I guess I should have searched more before posting this question, @runsongas has pointed out that the 1995 Luxfer is made of AL6061 which should be ok. The info is here: Is my cylinder made from the "bad" alloy aka AL6351?

    But I wonder if some dive shops will refuse to fill it at some point. I think I remember some dive shop employee saying something to that effect a few years back.
     
  5. Damselfish

    Damselfish Solo Diver

    # of Dives: 1,000 - 2,499
    Location: Boston
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    Maybe you'll never have a problem getting it filled, or maybe you'll run into a place with arbitrary date rules even though it's good. Personally I can't see buying an older tank and selling a new one just for the sake of color, especially with the possibility of that happening.
     
    DanSinks likes this.
  6. Stoo

    Stoo NAUI Instructor

    # of Dives: 5,000 - ∞
    Location: Freelton & Tobermory, Ontario, Canada
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    I have a 2005 Tahoe with 305,000 miles on it. Interested? :)

    I'd say clear of an Al tank that age too. I know up here, you wouldn't get that filled anyplace.
     
    DanSinks likes this.
  7. tmassey

    tmassey Barracuda

    # of Dives: 200 - 499
    Location: Shelby Township, MI USA
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    There's a lot of confusion around this.

    First, any tank made after certain dates in the early 1990's (like 1990, 1991) are made with the same alloy used today: 6061. Tanks before that may (and probably *are*) be made from a different alloy: 6351. That older alloy definitely suffers from Sustained Load Cracking (SLC). Many additional details here: PSI-PCI - A short Review of 6351 Alloy Aluminum Cylinders

    I'm not going to get into arguments for or against 6351, because that's not what you're asking. But's those tanks that have gotten dive shops used to forcing replacement of aluminum tanks. The question, is what about "old" 6061 tanks?

    There are three schools of thought with this.

    1) 6061 tanks are fine, and they'll always be fine. Go nuts.
    2) 6061 tanks *may* be fine, and they may not. Who knows, maybe they'll find SLC or something else?
    3) "Old" tanks should be condemned no matter what. Why risk it?

    Sadly, it seems that more and more *dive* *shops* are falling into categories #2 and even #3. Why? The most obvious and cynical reason is: they sell SCUBA tanks! They've gotten hooked on the candy of replacing "old" tanks, and why should they stop now? This just gives them a fear-mongering reason to sell more, and the fear gives them a fig-leaf to hid behind: we're doing it for your safety and that of our staff! Think of the children!

    The other reason: it lets them under-train their staff. It takes actual effort to get people to understand tank types, ages, brands, dates that are safe, etc. It's real easy to say, "Any tank over 20 years old is dead to us." In fact, there was a big thread on SB recently about a dive shop refusing to fill *steel* tanks because they were older than 20 years.

    Is this a cynical reply? You betcha. There's very little evidence that even 6351 tanks in proper hydro and with a proper visual eddy test are unsafe: DOT says that SLC to failure takes more than 5 years, and that proper VE at hydro will catch them. Let alone *any* evidence for failure of 6061.

    But in the end, unless you're gonna own your own compressor, you're at the mercy of dive shops both today and in the future. What percentage of shops? Enough that it comes up *routinely* around here. A quarry I've been to a few times was warning people that they would put in the 20-and-out policy for 2019. I haven't been there this year to know if they wen through with it or not. But this is not isolated.

    So this is a long-winded answer to say that scientifically, there's no reason to not use a tank from 1995. But practically, you will make your life noticeably harder, both now and likely in the future too.

    Edited to add: The responses above me say much the same thing, but without any real reason. Not a shot at their comments -- I agree with them. But the reasons are never really stated, it's just 'that's a bad idea'. (Mainly because IMHO, there is no scientific reason for it. But you can't beat the house... :) ) Which is why I own as few aluminum tanks as possible - just for deco bottles.
     
    Sam Miller III and DanSinks like this.
  8. DanSinks

    DanSinks Nassau Grouper

    # of Dives: 100 - 199
    Location: Massachusetts
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    I called 3 dive shops near me and asked what their attitude was towards older AL6061 tanks, two shops said as long as it passes hydro and VIP then they would fill it. The other shop said the same but added if there is visible damage, dents or anything like that they reserve the right to not fill it, which is reasonable.

    Did not buy the 1995 tank, ended up getting a newer tank, it was a better deal anyway, Yellow 2007 AL80 with a 1 year old Hydro. It looks brand new, not a single scratch! I know people will think the color is a bad reason, but I also wanted to be a little more visible on the surface, some places I go have a lot of boat traffic.

    Going to steel is good advice though, I'm thinking of a steel 100 or 120 for nitrox diving.
     
  9. tmassey

    tmassey Barracuda

    # of Dives: 200 - 499
    Location: Shelby Township, MI USA
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    SCUBA is a hobby. We do it for enjoyment, and if yellow tanks make you happy, that alone is good enough, all things being equal. I’ve seen plenty of color-coordinated divers, including tanks. That 2007 is a much better choice.

    I love the pretty colors of aluminum tanks — when they’re new. I tend to change that *rapidly* inside shipwrecks anyway... :)
     
  10. Billy Northrup

    Billy Northrup ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Key Largo / Norcal
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    A brand new AL tank with a pro valve is generally $169 bucks w/viz and air fill and can get them in any skittles color you want. I dive between Norcal and Key largo, anything exposure protection above 3mm gets a steel tank. Enjoy!
     

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