Glowing tritium on vintage GMT's?

[cruvon]

Hi, I recall I had read somewhere that a small batch of vintage GMT's tritium still glows, just wanted to know the reason for that especially since most of the other tritium vintage watches of that era don't emit a glow when exposed to a light source and viewed inthe dark. Also had read somewhere that some vintage tritium Rolexes do glow for a while and fade quickly,is that correct and if so, how quickly?

Thanks

[Mickey®]

It's been relumed in my opinion is the answer!

[U5512]

Some late '70s original dials with tritium still glow faintly at night...I was surprised when I first notice mine in the midde of the night. The glowing is consistent and won't fade as it's tritium.

[springer]

I've never seen a tritium dial or hands glow from the 1960's, 1970's and 1980's.

[greekbum]

I have had several 1966 Matte Dialed GMT's in the past that still glowed and the same goes for the submariners of the same batch. They will glow for a long time when charged next to a light. The markers have like a very light lime green tone to them. Many have mistaken this batch as relumed in the past. Here is a Submariner I had a while back that is from this batch.

[watchcrank]

mostly in the mid 2 million era in GMT and Subs as far as I have had anyway.

[Mickey®]

Does Tritium really "GET Charged" and glow more when next to a light??
Never seen that on my former Tritium dials...

[harry in montreal]

my 1981 datejust has the little glow blobs near the batons. every once and again, i glance down and they are shining back. kinda random. i tried to take it to the beach and bake it in the sun,but it had no impact. totally random. a possessed Christine Datejust

[toph]

Originally Posted by Mickey®

Does Tritium really "GET Charged" and glow more when next to a light??
Never seen that on my former Tritium dials...

Tritium is a radioactive substance and thus has a half life. My 96 sd still faintly glows when charged. I also had a vintage 70's heuer bund and because the tritium was much more thn t<25. , it was like a torch for a fe minutes after charging. The illumination capacity decreases over time

[linesiders]

I can make out my hands and plots on my Snowflake (79) if in a real, real dark room - but not from more that a couple inches. It is the same all the time and sun or LED has no bearing on it as far as I can see.

[Tools]

Tritium does not glow at all. It is a radioactive substance that emits high-energy particles that cause the phosphorous paint to glow..

So, if the tritium is active, the lume glows. If it is not active, the lume will not glow. However, some compounds can be excited slightly by light, so - light "charging" can last for a few seconds or minutes.... but it isn't the tritium that is charged, it is just the paint getting excited..

Tritium has a half-life of ~12 years, whether it is on the dial or on the shelf, so you never know how old the tritium on any dial is. After that 12 years it is half as energetic as it was new.... after another 12 years, that is halved again, and so on.. So, a 12 year old watch would have half the energy (if the tritium was brand new), a 24 year old watch would have 1/4 th energy, and a 30+ year old watch close to 1/8 the energy.... this just might not be enough to excite the paint but you still would not want to inhale it - hence, the danger of tritium..

[Pete17]

Originally Posted by cruvon

Hi, I recall I had read somewhere that a small batch of vintage GMT's tritium still glows, just wanted to know the reason for that especially since most of the other tritium vintage watches of that era don't emit a glow when exposed to a light source and viewed inthe dark. Also had read somewhere that some vintage tritium Rolexes do glow for a while and fade quickly,is that correct and if so, how quickly?

Thanks

perfectly normal mate.
Some Mk1 -> early Mk4 red subs still have a very faint glow too- especially on the hands.
Other models from the mid 60's have also been known to still glow. Very faintly though.
Rolex changed the quality/quantity (?) of tritium soon after. You won't find many, if any, models still glowing from the 70's.

[Robbyvm]

here's my 5513 from '66... the glowing doesn't last long but it's there

[Pete17]

That's an awesome lume still on that one Robby.

[Vincent65]

mine is a 1966 gilt dial 1675 GMT. NEVER re-lumed, and still holds a faint glow for a while:

[Puffy]

my 16750 from 1981 has no glow. how i like it...

[Gugnunc]

My T<25 1963 Explorer (dial and hands totally original) display hands with the tiniest degree of glow in the dark - but it takes some time for my eyes to see it. The dial markers, however, show absolutely nothing (different manufacturers of dial and hands?). Show it a strong light for just a few minutes and it glows like crazy - but only for a few seconds. I stopped being able to use it to tell the time at night in about the early eighties.

[harry in montreal]

Great desription Larry. THANKS

[Warnsboy]

Originally Posted by harry in montreal

Great desription Larry. THANKS

X2

[Robbie68]

1968 5513 all original, still has some glow if charged. From what I have read its the phosphor in the lume mix from around this time that gets charged. It will glow reasonably bright for a few minutes but fades pretty quick.
My 1981 Sub appears to have no glow when the lights are turned out but if I wake up in the night it has enough left to just make out the time.

[Mickey®]

I wonder how many people have "original dials" or "original Tritium" that glow...that are real good re lumes.

A lot can happen over that many years....

[Robbie68]

Originally Posted by Mickey®

I wonder how many people have "original dials" or "original Tritium" that glow...that are real good re lumes.

A lot can happen over that many years....

Could be the case for some but mid 60s are known for being 'chargeable'. Looking at the aging of the lume on mine it would have to have been relumed at least 30+ years ago to get the patina it has now which would make no sense. Also, with tritium having a half life of 12 years it's not inconceivable that a thirty year old watch would still glow, it would just be at a fraction of % of its original luminosity. My 16800 from 81 does still glow but if it's in the winder next to modern watches and you turn out the light it looks completely dead, wake up in the night and view it in isolation and it is just bright enough to make out the time which seems about right for tritium that is somewhere between a quarter and an eighth of its original glow.

[cruvon]

Thanks guys for the detailed info on this and the awesome pics. I am loving the enthusiasm on this topic:).

So I guess relying on the glow factor of the lume is not a wholly valid test by iteself in judging lume originality on vintages. So what other factors do we need to take into consideration when judging lume originality especially on tritium? I have seen some mention a puffed up look on tritium lume compared to luminova but not sure what would be a sure test for us to judge that. Some places even suggest a geiger meter:) for testing radioactivity on older radium lume. It can also be further complicated if the luminova lume was done years ago or worse still if a tritium relume was done decades ago. Add to that some modern techniques used to make a relume have the aged patina look. I am assuming the experts can always tell?

[mdw3]

Originally Posted by cruvon

Thanks guys for the detailed info on this and the awesome pics. I am loving the enthusiasm on this topic:).

So I guess relying on the glow factor of the lume is not a wholly valid test by iteself in judging lume originality on vintages. So what other factors do we need to take into consideration when judging lume originality especially on tritium? I have seen some mention a puffed up look on tritium lume compared to luminova but not sure what would be a sure test for us to judge that. Some places even suggest a geiger meter:) for testing radioactivity on older radium lume. It can also be further complicated if the luminova lume was done years ago or worse still if a tritium relume was done decades ago. Add to that some modern techniques used to make a relume have the aged patina look. I am assuming the experts can always tell?

Ultimately, if you have looked at many dials under high magnification, you can note differences in the structure of the various types of luminous matter used over the years, and what an original should look like. There is really no substitute for looking at a whole lot of dials very very carefully in order to learn the differences. If you compare truly original lume plots with even the best attempt by a clever restorer to mimic the effects of time, age and atmospheric conditions, you will see the difference. There are no perfect relumes.

Oh, and, yes, there was a brief period between c. 1966-68 when the original lume had a slight "greenish" cast to it, and those dials (later gilt/early matte subs and GMTs) do still glow, albeit faintly today.

Michael

[cruvon]

Originally Posted by mdw3

Ultimately, if you have looked at many dials under high magnification, you can note differences in the structure of the various types of luminous matter used over the years, and what an original should look like. There is really no substitute for looking at a whole lot of dials very very carefully in order to learn the differences. If you compare truly original lume plots with even the best attempt by a clever restorer to mimic the effects of time, age and atmospheric conditions, you will see the difference. There are no perfect relumes.

Oh, and, yes, there was a brief period between c. 1966-68 when the original lume had a slight "greenish" cast to it, and those dials (later gilt/early matte subs and GMTs) do still glow, albeit faintly today.

Michael

Thanks Michael, glad the experts can still tell but pity novices like me can't easily without a lot of experience handling watches!

[mdw3]

You will only learn by making your own mistakes. Probably a lot of them. Ask me how I know!

Michael

[AlTinkster92]

I owned Omega Mark 2 from 1970, still lumed for a brief second or so when under a neon light..

[mchad]

There are clearly differences in the lume composition. My 1990 SD has absolutely no effect from exposure to the brightest lights, yet still is completely visible (yet dim) at night. Not bright, but once my eyes adjust to the darkness, I can read the dial. And it stays the same brightness all night, the beauty of tritium. Unlike my service dialed 5513, which is a torch after exposure, but dimmer then the trit towards the early morning. I figure I still have a few years of tritium glow left... Which makes me happy.

[mikkolopez]

I have 1995 T-Swiss dial Explorer 2 and the lume is far gone. Though I still wish it'd glow even if just a tad.

[Throttle]

I have the following which i do not believe have been relumed having inspected under loupe very carefully many times.

MF 5513 from 1967 greenish patina
Mk1 1675 from 1967 greenish patina
Mk4 7928 from 1967 pumpkin patina

All 3 glow when charged with a strong source of light.
All 3 also fade very quickly losing most of the glow within a minute or two the most.

So either it’s factory legit or people just simply like to relume Rolex/Tudors particularly from 1967.

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