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New-to-me Seamaster and sourcing a NOS Crystal

  1. jawn

    jawn Jun 16, 2017

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    [​IMG]

    I just picked this guy up the other day (Case Ref 14765 SC, 180xxxxx serial, Cal. 552 movement), sold to me with original dial/hands/indices/crown, with an unsigned crystal. Being the completionist that I am, I'm on the hunt for a NOS crystal. I've been told that PZ5072 is the part number for the crystal, but I'm seeing listings for it with a steel tension ring or a yellow tension ring - anyone have any ideas as to which of the two I should choose/is most correct?

    Thanks in advance!
     
    alam likes this.
  2. JimInOz

    JimInOz "Helpful Hints from Heloise" of bracelet cleaning. Jun 16, 2017

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    Steel to match the case.

    Yellow would work as it would match the dial/hands, but I think it would look off.
     
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  3. cagkut

    cagkut Jun 16, 2017

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    To each his own of course but what difference does it make if the same piece of plastic has the Omega sign or not? I understand the incentive (even the urge) to equip a watch with all visible or invisible original parts, but come on, this is the plastic. What benefit are you going to provide to the rain forests man (just kidding here)
     
  4. alam

    alam Jun 16, 2017

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    a simple but pretty good looking Seamaster you got there :thumbsup: Enjoy! ... and I'd follow Jim's recommendation
     
  5. Peemacgee

    Peemacgee Purrrr-veyor of luxury cat box loungers Jun 16, 2017

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    The Omega crystals and tension rings are the correct fit.
    An after market generic crystal does not always do the job
     
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  6. Peemacgee

    Peemacgee Purrrr-veyor of luxury cat box loungers Jun 16, 2017

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    Looks like a yellow one already on there?
    I have a couple of steel case/gold indices Connies
    One with a silver ring, one with a gold ring
    The gold ring makes the indices 'pop' and looks a little dressier. (It came that way to me)
    I like them both.
    Personal taste in the end
     
  7. Archer

    Archer Omega Qualified Watchmaker Jun 16, 2017

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    Aside from the "collector" issues, there is a technical reason why using an Omega crystal is often important. Most Omega crystals that have tension ring use a stepped ring. Most generic crystals that have tension rings are not stepped. Not having this step changes how the movement is located in the case (which can cause problems), so having the right crystal with the right ring does make a difference.

    This is what the stepped ring looks like in cross section:

    [​IMG]

    The ring is facing down, so the angled portion on the bottom is facing the inside of the crystal, and the step or shelf you see on top is where the dial locates. It's not the trivial matter you believe it to be...

    For the OP - correct crystal for your case is 063PZ5072, steel ring.

    Cheers, Al
     
  8. alam

    alam Jun 16, 2017

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    ... and ladies and gents, ^^above^^ is ....

    :)
     
    Screen Shot 2017-06-16 at 8.46.58 AM.png
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  9. cagkut

    cagkut Jun 16, 2017

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    Seeing you are a watchmaker I am not going to argue with you, but my point is still valid: IF the aftermarket plastic does not cause problems (you are saying it can cause problems, not it will cause problems) why bother? I have a similar watch which I have been wearing for the last 10+ years with an aftermarket plastic with no problems whatsoever for example. A Speedmaster that I got few months ago also has an aftermarket plastic, which does not cause any issues. So I guess we can agree that it's not a must in a technical perspective, but a recommendation. Collector "obsession" are a different matter of course.
     
  10. Archer

    Archer Omega Qualified Watchmaker Jun 16, 2017

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    That you know of...you are completely free to believe whatever you wish mate.

    Cheers, Al
     
  11. cagkut

    cagkut Jun 16, 2017

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    What problem may have occured you reckon, that hasn't put out any signs after 10 years? This is a genuine question by the way.
     
  12. Archer

    Archer Omega Qualified Watchmaker Jun 16, 2017

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    When you don't have a step in the tension ring, this effectively shifts the movement in the case, further towards the case back. The effect of this will vary based on the watch, but for example in a Speedmaster, where the inner antimagnetic cover fitted to the enlargement ring is "clamped" by the case back, you are now increasing the pressure placed on the dial and movement within the case when the case back is fully seated. This can lead to damage on the periphery of the dial over time.

    Shifting the movement also shifts the stem location in the case tube - this photo illustrates what that looks like:

    [​IMG]

    Because the crown is always going to be centered on the case tube, this means the stem is perpetually bent. As you rotate the crown you are in effect flexing the stem back and forth, and as will happen if you bend a wire back and forth many times, it will work harden and eventually snap.

    In other cases moving the movement back in case may cause the rotor of an automatic watch to scrape on the inside of the case back immediately, or if not immediately as the bearing, axle, or pinion wear and it gets the inevitable play, it will scrape prematurely.

    You may be convinced that because you don't have any problems in the watches you own that this is a non-issue, and again you are free to believe what you like, but I can tell you this does cause problems. If you are happy to have aftermarket parts in your watch, that's up to you - many here are not for various reasons, and someone wanting to put their watch right isn't in any way a silly idea in the view of most here.

    Cheers, Al
     
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  13. Edward53

    Edward53 Jun 16, 2017

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    I can't comment on technicalities, but I have several 50s and 60s Seamasters and Constellations with stainless cases and gold furniture and they all have steel tension rings.
     
  14. jawn

    jawn Jun 16, 2017

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    Thanks for all of the information, guys. Y'all are the best.
     
  15. X350 XJR

    X350 XJR Vintage Omega Aficionado Jun 16, 2017

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    No one mentioned that on these uni-shell cases the crystal itself is stepped as well, holding the bezel on.
     
  16. cagkut

    cagkut Jun 19, 2017

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    Thanks a lot for your explanation.
    If I am not missing something, the tension ring is what you have been talking about., whereas I am talking about the plexis. Is there any reason to not use the tension ring together with an aftermarket plexi?
     
  17. Archer

    Archer Omega Qualified Watchmaker Jun 19, 2017

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    Tension rings come with the crystal and are not necessarily interchangeable - they can be different heights, shapes, and diameters. For example in the 2998 Speedmasters, the silver tension ring is a little wider than on others. Here is a watch I serviced with the tension ring and crystal that came with it:

    [​IMG]

    Customer wanted several things changed, and the crystal was replaced - the look is quite different with the proper crystal and tension ring:

    [​IMG]

    Since crystal manufacturers don't use any kind of standard, and the crystal is actually held in the case by the tension ring, swapping the ring could cause problems with water resistance or crystals falling out if it doesn't fit correctly. Case in point was this Speedmaster that came in with an aftermarket crystal after the owner had indicated the crystal had fallen out one day as he was walking around (he stuck it back in and sent the watch to me for a compete service):

    [​IMG]

    The watch came with some pretty severe issues in the movement from previous hack repairs, including this dandy "repair" to the minute wheel post:

    [​IMG]

    Square peg in a round hole anyone?

    [​IMG]

    Obviously this was repaired properly:

    [​IMG]

    This was a dealer sold watch, a well known dealer at that, and the aftermarket crystal had been glued in place because it didn't fit right:

    [​IMG]

    Unfortunately shoddy overall work often goes hand in hand with watches that come in with aftermarket parts, at least in my experience.

    Now could I potentially find an aftermarket crystal that has the same outside diameter as an OEM crystal, has the same height to properly clear the hands, has the same profile so the watch looks correct, and has the same dimensions and shape for the tension ring, so I could take the old tension ring out and put that in the new aftermarket crystal? Yes it's possible, but considering a new acrylic crystal from Omega is typically $35 (some with magnifiers are more but I rarely use those), in the big picture it's hardly a huge additional expense. This falls into the category of "no brainer" to me to just buy and use the real thing. The time I spent finding a crystal that would work would far exceed the cost of a new crystal from Omega. Trust me I have a huge cabinet full of acrylic crystals, and bags and bags of them on top of those that I've bought over the years for working on vintage watches where the manufacturer no longer exists. I dread having to go through all those to find something that will fit, clear the hands, and look right as it's often quite time consuming.

    If you want to try to save a few bucks by using aftermarket crystals, that's your choice, but to me it's a false economy at best. It may seem silly to you that people want an original crystal in the watch, but given what my customers ask for, I believe you are in the minority in this regard.

    Cheers, Al
     
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  18. cagkut

    cagkut Jun 19, 2017

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    I appreciate your explanations and try to learn from them but plse quit making subjective comments with each post you post. I am not "trying to save few bucks using aftermarket crystals" or such. Mind you, in a case that a watch is fitted with a plexi which does not carry an Omega logo, why bother replacing it, that's the starting point.
     
  19. Archer

    Archer Omega Qualified Watchmaker Jun 19, 2017

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    The OP clearly stated his reasons:

    "Being the completionist that I am, I'm on the hunt for a NOS crystal."

    You have made a subjective judgement that this is unnecessary for the OP to do. As I've said, in my experience you are in the minority as most of my customers want an original crystal installed. I've explained at length the potential technical reasons, but personally if you want to use whatever on your watches, it makes no difference to me. We can agree to disagree and the world will still turn...

    Cheers, Al
     
  20. cagkut

    cagkut Jun 19, 2017

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    Did I? Don't think so, reading again you'll see that I asked a question to him, I see no "judgement" there.And I know I can make my own choices and I also know that will not make a difference to you thanks a lot ;)