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Question re seals and gaskets

  1. Jensop

    Jensop Mar 15, 2019

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    hi all,

    Just had my watch serviced but unfortunately there is a problem with the chrono so the watch needs to be reopened.
    Is it ok to re-use the seal or should it be changed when the case back is removed?

    Also the crown was not changed. The watchmaker argues that it is fine and I should save my money. If inspected and found ok, should I accept this or insist on it being replaced?

    Finally, is there any difference between an original Omega gasket and a generic one?

    Thank you!
    Jens
     
  2. ras47

    ras47 Mar 15, 2019

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    Gaskets are pretty low tech, so a decent generic one would be fine. Personally I always insist on a brand new one whenever the caseback comes off. They're cheap, so why take a chance. It's not such a big deal on a non-diving watch like the Speedmaster. But with my Rolex GMT Master, because of all the things I do while wearing it, I can't see messing with a used gasket.
     
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  3. hbombkid

    hbombkid Mar 15, 2019

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    Replace the gasket and replace the crown to they are cheap.
     
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  4. Archer

    Archer Omega Qualified Watchmaker Mar 15, 2019

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    It depends on a few things. One you didn’t indicate what type of watch this is other than a chronograph, and Omega chronographs use different types of gaskets depending on the watch. If it has a snap on case back (Speedmaster date models) then it has a hard plastic gasket that is a one time use only item.

    The other thing you didn’t mention is if the gasket was changed at service, and if it was, and the watch has a screw in case back (O-ring style seal) then as long as it has been properly lubricated before the case back is screwed in, there’s no reason to replace it just for opening the case and closing it again. The grease applied helps keep the gasket from stretching as the case back is screwed down.

    How old is the crown? If it’s more than 2 or 3 years old, it should be replaced. However you have not said anything about pushers, so don’t forget those have gaskets in them as well.

    If it’s a standard nitrile O-ring, then all you need is one of the correct size. If it’s the hard plastic style it will be more difficult to find the size that you need.

    Cheers, Al
     
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  5. Meme-Dweller

    Meme-Dweller Mar 15, 2019

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    It depends on the gasket. I've had a Seamaster and a Speedmaster with the caseback opened and screwed back at least 10 times and there is still no problem passing pressure tests. However, let's just say every single Seiko I've opened has needed a new gasket because they stretch out and self-destruct after every use.
     
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  6. Jensop

    Jensop Mar 16, 2019

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    Thank you!

    The watch is a Speedmaster Pro 1861.

    The gasket was changed at service, at least I received an o-ring back in a little bag along with two little o-rings from the pushers.

    Also there are two little pins or so in bag. Guessing they are from the pushers.

    So the pushers were not changed but the o-rings were.

    The old returned ones seem pretty intact to me - at least they are not dust to my eye.

    The crown is certainly more than two years old - more like 8-10.

    Thanks again, Jens
     
    image.jpg
  7. M'Bob

    M'Bob Mar 16, 2019

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    Al, is this an age phenomenon only, or does use factor in? In other words, if mostly unused, is that time frame extended?
     
  8. Archer

    Archer Omega Qualified Watchmaker Mar 16, 2019

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    When installed on a watch, the seal is being compressed even if it’s not being rotated. Over time the seal will lose flexibility and will not have as much pressure on the case tube, so will be less effective.

    If a crown is being used all the time like in a manual winding watch, I would expect it to fall sooner.
     
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  9. Jensop

    Jensop Mar 16, 2019

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    I realise prices will probably vary from country to country, but rough ballpark, how much is a crown supplied by Omega?
     
  10. dennisthemenace

    dennisthemenace Hey, he asked for it! Mar 16, 2019

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    Al, do those O rings look like pusher seals to you?
     
  11. Jensop

    Jensop Mar 16, 2019

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    image.jpg
    Curious as to why you are asking.


    Here is another picture..
     
  12. dennisthemenace

    dennisthemenace Hey, he asked for it! Mar 16, 2019

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    Yes, they probably are .Forget I asked.
     
  13. Jensop

    Jensop Mar 17, 2019 7:54am

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    Probably?
    Are you thinking they look wrong?