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Tritium lume doesn’t light up under UV

  1. jerryct Sep 10, 2018

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    Hi OF,

    I have a wakmann triple date. On the surface it looks legit. However, it “failed” the UV light test, the lume markers do not light up under UV.

    Just wondering if there is a possibility of relume ? Tritium markers that does not light up always mean relumed?

    I will try to update with a photo under UV.

    8CAF85A4-A032-460E-BC84-90017056DEB2.jpeg
    23CF0921-D882-4814-A6A9-0BC1308E2042.jpeg
     
  2. MrJKLFoams Sep 10, 2018

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    Looks like the tritium are depleted and needing replacement. I used to have a ball watch the orbital 2 looks amazing in the dark and light up more under UV unfortunately I sold it due to sz and needs to fund my first crown.
     
  3. Davidt Sep 10, 2018

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    I've never had a tritium dial not glow for at least a couple of seconds under uv. In my experience even the most mouldy, grey crappy lume tends to glow.
     
  4. jerryct Sep 10, 2018

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    Is it possible for the tritium to be thinly applied and has flaked off?
     
  5. JimJupiter Sep 10, 2018

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    I heard there are some Tritium Rolex watches that don't glow, since they used another chemical ingredients than zinc sulfide. Maybe its the case here too. I never had a non glowing Tritium watch either. In differ to that, not all my Radium watches react to UV.

    Nico
     
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  6. Canuck Sep 10, 2018

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    Some substances that are meant to phosphoresce, will glow in both short wave and long wave UV light. Other substances will only phosphoresce in one or the other wave length of UV light. Might be a clue.
     
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  7. jerryct Sep 10, 2018

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    6EBE4F1B-6E77-4643-844E-658657CAC7C0.jpeg B0AEC1A0-E1D5-47B0-B046-583E43154703.jpeg A8652E01-7E29-4181-8E3A-2ED738BAE0F7.jpeg

    Alright here’s some photos under UV. The hands glow fine under the UV. Can see some hint of glow on some of the markers.
     
  8. kreyke Sep 10, 2018

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    Hello! I’m interested to know if this watch has the original lume as well. The other examples of wakmann I’ve seen have white lume.

    I’m not sure if the majority of wakmanns are all relumed or if wakmann used some type of lume that doesn’t develop patina?
     
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  9. erpin9 Sep 10, 2018

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    I believe tritium has a half life on the average of 20 years so after 40 years it will hardly glow anymore even under U.V. light. Your Wakmann I think is more than 40 years old already which explains why it does not glow anymore.
     
  10. Foo2rama Keeps his worms in a ball instead of a can. Sep 10, 2018

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    incorrect. The stuff that the tritium excites to make it glow will still glow. Tritium did not need to be charged, it glowed from the break down of tritium, which will eventually run out hence no more glow.
     
  11. jerryct Sep 10, 2018

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    There is still some faint specks of glow on the markers but of course it is a drastic difference from my other tritium watches which shine quite brightly under UV.

    Not sure if this is a case of relumed or is it a case of very thinly applied lume.
     
  12. larryganz The cable guy Sep 10, 2018

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    True. I once owned a 1980's Rolex Submariner that the Tritium would only glow while it was under the UV light but it would instantly stop glowing when the light was turned off. There was no residual glow for a few seconds after the UV was removed, as I see with my 1976 Speedmaster Pro.
     
  13. Mouse_at_Large still immune to Speedmaster attraction Sep 11, 2018

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    If you want to know a bit more, this Wiki article has a section on phosphor degradation. Logically, if the phosphor is completely degraded then no excitation source, including shining UV on it will have any effect.
     
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  14. Rodsch Sep 11, 2018

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    I think that after a certain time Tritium has no more lume. Tritium can´t be "reloaded" like luminova
     
  15. asrnj77 Sep 11, 2018

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    I thought I heard that some shops like LA Watch Works is using real tritium to relume watches. You don’t find many places with leftover radioactive paint to play with. It’s an option but I don’t think they’re cheap.
     
  16. jerryct Sep 11, 2018

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    Interesting discussions. I guess it depends on the type of tritium being used?
     
  17. TDBK Sep 11, 2018

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    There's only one type of tritium; it's just hydrogen with two neutrons (the most common hydrogen isotope has no neutrons, deuterium has one, and tritium has two), the word is from the Greek tritos ‘third.’ because it's the third isotope and/or because it has an atomic weight of about 3 (3.016). So there's no variation in tritium, and because it's chemically identical to hydrogen, you can incorporate tritium into any chemical compound which has hydrogen in it: water, polymers, whatever, or you can keep it as hydrogen gas. Tritium has a half-life of 12.3 years: every 12.3 years, there's a 50/50 chance any particular atom of tritium will spontaneous convert itself into an atom of helium, releasing an electron at the same time. The electron hits a phosphor and excites an electron in that phosphor to a higher energy state; when it collapses back to a stable energy state, it emits a photon of light, with the color of the light depending on the gap between the two states. There are different phosphors in use, including zinc sulfide and strontium aluminate; these molecules are put into a matrix with other elements (the activator) which affect the quantum states available and change the color of light emitted, etc. Then these materials will be made into a paint by mixing them with binders, etc.

    While electrons from tritium decay activate the phosphors in the paint in the usual use case, they can also be activated with UV, and because it can take a measurable period of time before the phosphor electrons collapse and emit light, there's an opportunity to see the phosphors glow after they've been exposed to UV.

    So the tritium is the same and there's a pretty limited number of the phosphors at the core of the phosphorescence. What does vary is the impurities used with the phosphor to tune the color and persistence of the light, the binders, etc. This is what causes the lifespan and quality of various tritium paints to vary. They will also respond to UV in different ways depending on the wavelength of the UV, etc. I agree with @Canuck that the failure to glow may be because of the short-wave vs. long-wave illumination difference.

    Nothing can be done to change the rate of tritium's decay, it's fundamental physics. The phosphor and paint may degrade at different rates depending on its formulation.
     
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  18. oddboy Zero to Grail+2998 In Six Months Sep 11, 2018

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    ^awesome explanation!
     
  19. BlackTalon This Space for Rent Sep 11, 2018

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    Finally a great explanation of why so many watches have helium escape valves! ::stirthepot::
     
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  20. ConElPueblo Sep 11, 2018

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    How dare you bring science into this?!? MODS! BAN HIM!