Why doesnt a watch still glow after 44yrs?

[Mikel212]

Trintium has an 1/2 life of 12 yrs from manufacturing, so after 44 yrs, it should still have a glow of 1/8 to 1/16 of the original. In theory, shouldnt we be able to see a faint flow on a '67 Sub in a pitch dark room? I see nothing in mine.

Would one see something different if infra-red or a different spectrium were used?

[matt4hand]

You can with some of them.

I had a vintage M first 5513 that would glow for about 5 seconds in the dark.

[conrail]

Charge it against a bright light source for a minute then go into the pitch dark; you might see a faint glow. It is not the tritium itself that glows, but the reaction it causes when mixing it with the certain paint; that chemical reaction may have broken down even though the tritium is not completely dead.

[Mikel212]

Thanks Conrail, that makes alot of sense.

So, a 44yr watch can still be radioactive, but not stong enough to react with the paint to get it to glow.


This got me thinking since I saw a post for a vintage sub. Seller claims that its over 40yrs, but still glows strong. Maybe hes referring to the glow AFTER exposure to strong light source and not the 24/7 glow reacting to the Trintium. Because if thats not the case, there is no way in hell that the "original-untouched" dial should still be glowing on its own.

[azguy]

Originally Posted by Mikel212

Trintium has an 1/2 life of 12 yrs from manufacturing, so after 44 yrs, it should still have a glow of 1/8 to 1/16 of the original. In theory, shouldnt we be able to see a faint flow on a '67 Sub in a pitch dark room? I see nothing in mine.

Would one see something different if infra-red or a different spectrium were used?

Doubt you will see much of anything at this point

[jamesw]

Just a quick question for those who can remember. Did a Tritium dial from new glow green just like a superluminova dial or did it have different colour or appearance?

[GeoGio Greece]

Originally Posted by jamesw

Just a quick question for those who can remember. Did a Tritium dial from new glow green just like a superluminova dial or did it have different colour or appearance?

From what I remember, my DJ - 1983 had white greenish dots, the same with my current GMT 16700 -1993.

The Sub, 5513 - 1983 I do not remember at all !

I tried many times to "charge" it under the Greek sun, but no results

[jamesw]

Thanks George!

[Paladin]

Here is an excellent explanation of the phenomena from TRF reference library.

http://www.rolexforums.com/showthread.php?t=123465

[conrail]

Originally Posted by Mikel212

Thanks Conrail, that makes alot of sense.

So, a 44yr watch can still be radioactive, but not stong enough to react with the paint to get it to glow.


This got me thinking since I saw a post for a vintage sub. Seller claims that its over 40yrs, but still glows strong. Maybe hes referring to the glow AFTER exposure to strong light source and not the 24/7 glow reacting to the Trintium. Because if thats not the case, there is no way in hell that the "original-untouched" dial should still be glowing on its own.

The seller might be referring to that - it potentially could have some original glow to it. Or it has been relumed.

[inspires]

Originally Posted by Mikel212

Trintium has an 1/2 life of 12 yrs from manufacturing, so after 44 yrs, it should still have a glow of 1/8 to 1/16 of the original. In theory, shouldnt we be able to see a faint flow on a '67 Sub in a pitch dark room? I see nothing in mine.

Would one see something different if infra-red or a different spectrium were used?

I have a '66 GMT Master with original and non-relumed dial that glows briefly after exposure to direct sunlight. However, I also have a '68 5512 that does not glow. I've read that it has to do with the inconsistency of tritium mixture used by Rolex, so I wouldn't worry too much.

[toph]

it is the <25 thats is the major factor

[achova]

I can't seem to find the thread but a couple of us have (had) Explorers & Subs from the mid-60's (post Radium) - which IIRC were from within a quarter or two of one another - all with strong self-illuminated glow. Undoubtedly due to a batch with just the right mixture.

[Jagatai]

My 67 5512 glows strongly for five seconds when exposed to a strong light source.

In a pitch dark room left in there for awhile it glows but faintly.

My 78 5513 doesn't glow when exposed to a strong light source but glows when left in a pitch dark room, actually never knew it glowed at all till I woke up in the middle of the night.

[Gugnunc]

Agree with some of the above. My own watch (48 years old) has indices, triangle and 3,6,9 which show nothing in the dark and I do mean nothing, zero, zilch, nada. However the hands (original, as is the rest of the dial) do show the faintest glow after being in total darkness for several hours - not enough to tell the time with but enough to let you know that something is there. My guess is that there are more factors involved than just the tritium activity - probably involving the formulation of the "paint".
A 48 year old watch should, in theory, have tritium which is down to 7.3% of its original activity and that seems to be about right for the hands - but why nothing form the indices if not down to the "paint" involved?

[conrail]

Originally Posted by Gugnunc

Agree with some of the above. My own watch (48 years old) has indices, triangle and 3,6,9 which show nothing in the dark and I do mean nothing, zero, zilch, nada. However the hands (original, as is the rest of the dial) do show the faintest glow after being in total darkness for several hours - not enough to tell the time with but enough to let you know that something is there. My guess is that there are more factors involved than just the tritium activity - probably involving the formulation of the "paint".
A 48 year old watch should, in theory, have tritium which is down to 7.3% of its original activity and that seems to be about right for the hands - but why nothing form the indices if not down to the "paint" involved?

Hands/dial markers were done by different manufacturers so the mixture is undoubtedly different, hence some being dead and some still having a faint glow

[cajunron]

I think you're splitting hairs!

[subtona]

there are definitely different qualities of tritium that have been used...i had an older model that was much brighter than a newer of the same design.

i believe its just a stirred up mixture, sometimes you get a good stir, sometimes not so much?

[Gugnunc]

Thanks Conrail, I didn't know that different manufacturers were involved.

[Andad]

Wot's trintium?

It won't glow.