Failed pressure test

Discussion in 'Other Watch Brands' started by Archer, May 24, 2011.

  1. Archer

    Archer

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    I thought I would share something that is fortunately a rare occurrence - a failed high pressure wet test.

    I received the watch in question to do some minor work to it (bezel insert swap and removal of the cyclops) and I won't name the brand, but it is a Rolex look alike with a Swiss movement. Here is a shot with the case back removed:

    [​IMG]

    The cyclops was quite difficult to remove, and to do it without risking the remainder of the watch, I popped out the crystal which is a simple press fit with a gasket:

    [​IMG]

    After removing the cyclops, and cleaning up the sapphire crystal, I pressed it back into place:

    [​IMG]

    Replaced the case back gasket:

    [​IMG]

    Lubricated with Fomblin grease:

    [​IMG]

    Ready for testing with the stem/crown removed from the movement and installed in the case:

    [​IMG]

    First the dry test to make sure a gasket isn't pinched or something like that:

    [​IMG]

    Passed with no troubles using the diver program of -0.7 bar and +10 bar:

    [​IMG]

    So these next steps illustrate why it's a good practice to test the empty case before doing this with the movement in place.

    Off to the room where the wet testing equipment is:

    [​IMG]

    Watch case is loaded into the chamber and everything is sealed. When it's a brand that I don't have a procedure for, I use the Omega work instructions for doing this test, so no pressure is added at this point - the watch sits for 30 minutes like this:

    [​IMG]

    After 30 minutes I increase the pressure - this watch is rated for 300 metres, so that would be 30 bar + the 25% safety factor. However, I have had a watch from this company's "sister" company fail before, so knowing that I just use the 30 bar pressure:

    [​IMG]

    Here you can see the case inside, and see that the gauge is at 30 bar:

    [​IMG]

    After 1 hour at this pressure, I drop it back to zero, and let the watch sit for 3 minutes:

    [​IMG]

    Having a peek inside, I see what looks like a failed test with water inside the case at the 2 red arrows - the other bubble is in the chamber:

    [​IMG]

    After 3 minutes the watch is pulled out:

    [​IMG]

    Here is where I would normally dry it off, put in on the heating unit for 30 minutes, and then place a drop of room temperature water on the crystal for a minute. Then wipe away that water and use a loupe to look for condensation under the crystal, but there's no need for any of that:

    [​IMG]

    Back to the bench to open the case, and there's no doubt this one leaked, as there's water inside the case at the red arrows:

    [​IMG]

    In the previous instance, I tested the failed watch several times with the wet testing machine to find out where it failed. I started at 10 bar, and increased in 5 bar increments and it was fine to 25 bar, or 250 metres. But it failed again at 30 bar, so these watches did not meet their stated depth rating.

    I don't know how common this is, but these are the only two watches I've had that could not meet their stated depth ratings. When my prior client emailed the company after his failed a few years ago (it was a new watch and all I did was open the case back, regulate it, and close it back up) the company responded by saying "thanks for letting us know" and that was it. Realistically, 99.9% of the population does not need 300 metres depth rating, but in many ways that's not the point!

    Anyway, not often this happens so I wanted to share. Thanks for looking.

    Cheers, Al
  2. Baco Noir

    Baco Noir

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    Interesting to see Al. If it had passed, do you then complete the reassembly and retest it - dry then wet again? :thinking:
  3. Pete17

    Pete17

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    Thanks Al, That watch Co needs to lift it's game.
  4. SPACE-DWELLER

    SPACE-DWELLER

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    Scary stuff! :eek:

    Thanks for sharing, Al! :goodpost:
  5. Archer

    Archer

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    Yes, exactly. The final test is wth everything installed, after a passed wet test on the first go with empty case, a passed dry test on the second with everything installed, and after I know I won't need to open the case again for something like regulation.

    Cheers, Al
  6. DSimon9

    DSimon9

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    Good thing it was an empty case. :yikes:
  7. colemanitis

    colemanitis

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    :goodpost:, Al! :thumbsup:
  8. Kiwi

    Kiwi

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    :goodpost:

    Great and intresting post, Al :yourock:

    Blown away by all the testgear You have,..guess here we are still in the stoneage:lol::dummy:
  9. Vincent65

    Vincent65

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    fascinating, thanks once again - very informative
  10. Kokyuryoku

    Kokyuryoku

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    Awesome post Al :thumbsup: I learn something new everytime. Thanks for sharing. :cheers:
  11. SLRdude

    SLRdude

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    Thanks Al!

    You are right, that watch would be just fine for 99.999999 percent of population.
    However, if they cut corner there... where else have they done the same during the design and build stages of the watch?
  12. Goldbug

    Goldbug

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    Excellent information Al.

    You mentioned you used the Omega testing procedure for this watch. Do most watch companies have a procedure which you can follow OR do you have to develop one on your own based on the watch? :dunno:


    John
  13. RW16610

    RW16610

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    :goodpost: Al, it was very interesting :cheers:
  14. SSD

    SSD

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    Is the Omega procedure much different from other companies' way of doing things? Or are things just done in a different order?

    :goodpost: Al, very interesting!
  15. Archer

    Archer

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    Glad you enjoyed the post. The procedures have slight variations sometimes (durations, etc.), but for the most part they stick to the same basics.

    Cheers, Al
  16. Archer

    Archer

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    Another example

    Well thought I would share this one too - have a couple of Kobolds in and one kept failing the pressure testing in the wet tester. I used my dry tester in the "leak finder" mode, which pressurizes the watch for an extended period of time, so if it is leaking the pressure inside the case will build up. Then when the machine depressurizes, you can remove the watch and place it in a glass of water to see if any bubbles escape, and find the leak.

    Note that the case is empty for this test. Here is a video showing where the leak was on this watch:

    http://youtu.be/ii-NNk0Z0SY

    It was leaking from the Helium escape valve. I took the valve apart, cleaned everything (had some dirt inside), inspected the seal, and lubricated it properly, and that solved the problem.

    So even watches rated for 1000 meters can still leak!

    If you dive with your watches or get them wet often, I recommend regular leak tests.

    Cheers, Al
  17. SLRdude

    SLRdude

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    Thanks for the additional info Al.
    How often do you think a test should be performed? I think the book says once a year?
  18. RW16610

    RW16610

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    Yeah, thanks for posting that extra info and video there :thumbsup: Learning so much from you, Al :cheers:
  19. Archer

    Archer

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    Hey Chip - I would say once a year is a good start. It really depends on how much use and abuse the watch is subjected to. The vast majority of watches I get that have pressure problems are related to the crown seals, so if you have a habit of winding the watch using the crown a lot, this would be a factor to take into consideration when deciding on a frequency.

    Cheers, Al
  20. Aerome

    Aerome

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    Good one, Al. And to think it was only a few years ago you that learned to tell time! Now you have the time to make accurate time for everyone.

    Al II