Dive Tanks?

saltydog251saltydog251 Posts: 136 Officer
I have a couple of aluminum 80s that have been in my garage for over 10 years. They still have air in the but havn't been tested.

How can I tell if they're still good?

Thanks

Replies

  • Lobstercatcher229Lobstercatcher229 Posts: 4,843 Officer
    I have a couple of aluminum 80s that have been in my garage for over 10 years. They still have air in the but havn't been tested.

    How can I tell if they're still good?

    Thanks

    To tell if they are good you should take them somewhere to be hydrostatically tested (it needs doing every 5 years). That will tell you if they are still good and will cost you something, I forget what I paid last time I did that.
  • saltydog251saltydog251 Posts: 136 Officer
    Thanks

    If I'm reading the dates right they are from the 80's. Is there a point that they are considered too old?
  • Lobstercatcher229Lobstercatcher229 Posts: 4,843 Officer
    Thanks

    If I'm reading the dates right they are from the 80's. Is there a point that they are considered too old?

    I have 2 older tanks from the 80s that have passed inspection including one I paid 5 bucks for at a garage sale. I think that as long as corrosion or some other problem hasn't ruined them that they are ok if they pass inspection.
  • IntheslotIntheslot Posts: 282 Deckhand
    As long as they are not Luxfers, you are okay.

    If they are Luxfers the dive shops will not fill them but you could get probably 25-30 bucks each from a recycle place as scrap if unpainted and valve removed.

    If other than Luxfers go get em tested. I have a few Catalinas from the 80s that are still in use
  • saltydog251saltydog251 Posts: 136 Officer
    Actually they are Luxfers but the local shop says they can still be used.

    :huh
  • IntheslotIntheslot Posts: 282 Deckhand
    Good for you, my shop won't fill em.
  • saltydog251saltydog251 Posts: 136 Officer
    Actually I was going to put them on Craigslist but don't want to get anyone killed.
  • Lobstercatcher229Lobstercatcher229 Posts: 4,843 Officer
    Actually I was going to put them on Craigslist but don't want to get anyone killed.


    every once in a while the news does have a story of a tank blowing up and killing someone.
  • launchpadlaunchpad Posts: 386 Officer
    If they are luxer 87 or earlier they are scrap metal.
    "When you get to the end of your rope, tie a knot and hang on." Franklin D. Roosevelt
  • rodzrodz Posts: 660 Officer
    launchpad wrote: »
    If they are luxer 87 or earlier they are scrap metal.

    :Agree
    I have a pair I took in several years ago that I still own but never use. The dive shop owner could tell them apart from 30 feet away - they have a 1987 manufacture date. Last time they passed inspection was 1993. Something about a bad alloy that was used . . .
  • Lobstercatcher229Lobstercatcher229 Posts: 4,843 Officer
    rodz wrote: »
    :Agree
    I have a pair I took in several years ago that I still own but never use. The dive shop owner could tell them apart from 30 feet away - they have a 1987 manufacture date. Last time they passed inspection was 1993. Something about a bad alloy that was used . . .

    Is there a luxfer story involving one blowing up?
  • IntheslotIntheslot Posts: 282 Deckhand
    More than once I heard. Guess there is an alloy that Luxfur used through 1987 within the neck that cracks and leads to explosion. That alloy wasn't used by other manufactures or so I'm told. But most dive stores will not fill the older Luxfers for that reason.
  • Prop BlastProp Blast Posts: 375 Officer
    The "issue" with Luxfer tanks is that they built aluminum tanks using two different aluminum alloys in the 80s. The alloy in question was the 6351 alloy and was used through 1988. However, that doesn't mean just because your tank was made in 1988 or before, it's no good.

    The other/new alloy is 6061-T and is fine as long as it continues to pass hydro and VIP. Any competent dive shop will know this. If your shop says, "We don't fill old Luxfers" -- find a new dive shop. The type aluminum used is stamped on the shoulder of the tank, so it's not rocket science to determine what aluminum was used to make the tank.

    A few years ago, Luxfer offered a turn-in credit on those "bad" tanks towards new Luxfers -- it was a good deal. You got new tanks for a redued price (valve not included). That offer is over (I think it ended in 2004).

    So the answer is to take them to a real dive shop and ask. I had my tanks hydro'd a couple of years ago and it was $45 per if I recall.

    If you're looking to resell them, take them to a dive shop and have them check the number code -- it's not the date of manufacture. If they're the "good" aluminum, you have a choice: 1. Pay the shop $X to bleed and do a quick Viz to see if they're worth sending off to hydro. #2. Just bleed off and sell for scrap.

    If they check out okay, the dive shop will probably pay you $50 or 60 on the spot and put them in their rental stock.

    Personally, I would NEVER buy a used tank that didn't have a current hydro and VIZ -- too much risk of throwing your money away.

    PB
  • saltydog251saltydog251 Posts: 136 Officer
    I called Luxfer and they said the tanks are fine but they need to pass an eddy current test.

    Anyone heard of this?
  • TrollaltdeleteTrollaltdelete Posts: 646 Officer
    Interesting video. Not about the luxfers, but it shows the power of a tank.
    Take out your boat, make a memory!
  • saltydog251saltydog251 Posts: 136 Officer
    Got $17 each at the scrap yard
  • Lobstercatcher229Lobstercatcher229 Posts: 4,843 Officer
    Interesting video. Not about the luxfers, but it shows the power of a tank.

    I had often wondered what would happen if you knocked the top off a tank, now I know! :thumbsup
  • cmatthews7cmatthews7 Posts: 17 Greenhorn
    Bottom line is that a poor quality alloy, 6251, was used and not just by Luxfer. I think there is another (6289, maybe?) that was also used and has been implicated in neck cracks which eventually disintegrate (explode). It is not worth the risk of hurting you or someone around you (I would not allow those older tanks on my boat) as if they go they will kill or maim anyone in the vicinity. Even if a shop does a thorough vis,which most good shops do, those neck cracks are very hard to detect. How do I know? Deep 6 in Lakeland (great shop btw) discussed with me the issues and I looked at my own tanks. After realizing I was afraid to use them, I put them (3) on a band saw ande cut the tops off before scrapping them. One did indeed have a very small crack in the curve of the top of the tank, towards the very bottom of the threads. Would a shop have caught it, maybe, but not worth the risk. Google search tank explosions.
  • Prop BlastProp Blast Posts: 375 Officer
    I called Luxfer and they said the tanks are fine but they need to pass an eddy current test.

    Anyone heard of this?

    Yes, it's what dive shops call a "VIP+". They do the regular viz inspection, then an eddy test (that's the "+" part). It's to ID cracks in the aluminum that they cannot pick up with the light. No big deal at any good dive shop.

    PB
  • cmatthews7cmatthews7 Posts: 17 Greenhorn
    BTW, I think it was a 6351 alloy, and no offense, but why would you risk it? There are so many sites available that discuss the "flaws" in this alloy and numerous articles about "fast-cracks" developing under load, how in the world can you think about keeping them? I am not a mettalurgy expert, but I am very advanced in scuba and have done a lot of research into these tanks, and bottom line is get your 30-40 bucks at a scrap yard and either rent tanks, buy some used ones off Craigs list that are good, or borrow a buddies. I am not in the dive business, but we are all in the safety business. I could not live if I hurt someone because I was trying to skimp by on VERY questionable tanks. There are newer models tanks in hydro available for 60-100 bucks all day. I had a half dozen or so, scrapped them, bought some replacements off CL and 4 new hp steels (love them but pricey). Look at this site and make your own choice: http://www.scubabomb.freeservers.com/

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