1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Pre-sale crack bottle excitement!

Discussion in 'Dive Equipment' started by Tribal Chestnut, Aug 12, 2019 at 11:16 AM.

  1. Tribal Chestnut

    Tribal Chestnut Well-Known Member
    UKD Supporter

    Joined:
    Aug 6, 2015
    Messages:
    983
    Likes Received:
    409
    I need to have a bit of a clear out and one of the items that has to go is (was!) my old crack bottle DSMB.

    I bought this sometime ago and it has sat in a drawer being annoying for a few years now.

    Way back when, I used to operate it following the standard protocol of my old PADI club - crack it right open and let it fly....

    I’ve known the drawback of this method for a while now so I thought that, prior to selling it, it would be prudent to carry out a few ‘tests’ to ensure the fucker was not rotting from the inside.

    The bottle was attached to a full fifteen litre of mine, which was then opened up. I gently opened the crack bottle a smidgen.....and it held. Fucking brill thought I, as I very gradually increased the pressure.....suddenly BANG, not so fucking brill now.

    Oh well. At least I’m not stuck having to refund some poor sod that I might have sold it to, or having to explain to a coroner how it was just a simple accident that the buyer ended up with a crack bottle embedded in their bonce.
     

    Attached Files:

    NickPicks, kingo1984, Wibble and 5 others like this.
  2. NickPicks

    NickPicks Active Member

    Joined:
    Jun 7, 2010
    Messages:
    485
    Likes Received:
    169
    Did the valve just pull out of the threads of the aluminium?
     
  3. Tribal Chestnut

    Tribal Chestnut Well-Known Member
    UKD Supporter

    Joined:
    Aug 6, 2015
    Messages:
    983
    Likes Received:
    409
    The threaded section of valve is still in the bottle, obviously the bond between thread & bottle was stronger than the valve itself.
     
  4. MadUKDiver

    MadUKDiver New Member

    Joined:
    Jan 2, 2017
    Messages:
    6
    Likes Received:
    0
    Wow, that's unusual. Normally any sea water that gets into the bottle creeps into the threads and, when the valve is unscrewed, the threads are damaged and the bottle must be scrapped. The valve thread breaking like that would typically be due to a drop shearing the thread or excessive force exerted on the brass when unscrewing a jammed thread.

    Glad you found this in a controlled test, could have been very nasty.

    Plans are being considered to remove the exemption for small cylinders which might make these rather less popular when they need a formal test every 2.5 / 5 years.
     
  5. jb2cool

    jb2cool Moderator
    Staff Member

    Joined:
    Jan 20, 2008
    Messages:
    3,261
    Likes Received:
    539
    Since people trans fill from an existing cylinder rather than asking a shop to fill them I can't see that making any difference.
     
    Dave Whitlow likes this.
  6. Wibble

    Wibble Fish don't talk
    UKD Supporter

    Joined:
    Apr 7, 2014
    Messages:
    5,933
    Likes Received:
    1,341
    Isn't it a design flaw? As in there should be an, errm, regulator type thing that prevents water ingress below, say, 10 bar? Something like a spring valve? That then means it can't fully empty even when opened fully on the bottom.

    Always hated those things. Glad I sold mine. Hopefully @jps still has both hands.
     
  7. nickb

    nickb Well-Known Member

    Joined:
    Oct 13, 2009
    Messages:
    640
    Likes Received:
    328
    On the good ship Huskyan, we have a 15l cylinder kept full for people to charge these things. We ask people to fill them with their crack bottle pointing out to sea for exactly this reason.
     
    NickPicks likes this.
  8. Wibble

    Wibble Fish don't talk
    UKD Supporter

    Joined:
    Apr 7, 2014
    Messages:
    5,933
    Likes Received:
    1,341
    Is that failure mode common?
     
  9. nickb

    nickb Well-Known Member

    Joined:
    Oct 13, 2009
    Messages:
    640
    Likes Received:
    328
    No, but once is enough!
     
  10. Iain Denham

    Iain Denham Active Member

    Joined:
    Sep 11, 2012
    Messages:
    749
    Likes Received:
    157
  11. Wibble

    Wibble Fish don't talk
    UKD Supporter

    Joined:
    Apr 7, 2014
    Messages:
    5,933
    Likes Received:
    1,341
    Sooner use the suit inflate, but we don't want to practice one-handed disconnects and reconnects...
     

Share This Page

  • About Us

    Our UKDivers community has been around for many years and prides itself on offering unbiased, helpful discussion among people of all disciplines and abilities. We are working every day to make sure our community is one of the best and friendliest around.
  • Support us!

    The management works very hard to make sure the community continues to run reliably. Care to support us? All donations go to the running costs of the forum: hosting charges, software maintenance, etc. We'd really appreciate it!

    Choose option:  

    UKD Username: