How Long Will Super Luminova Last?

I have a 20 year old Seiko diver that still glows amazingly well. I am unsure as to whether Seiko uses superluminova, I’m sure somebody will enlighten me. However it is modern no-rad lume and has endured quite well thus far.

Seiko uses their own proprietary photoluminescent material called lumibrite

That serves as an excellent reference point. Has the lume developed a creamy hue as it ages?

My Seamaster is going on 13 years and still goes well. Perhaps it fades a little faster than it used to - or my eyes do perhaps... 🤔

Tritium is different than lume.

Tritium is a low-level radioactive gas & is housed in tubes. It has a half-life of around 12 years. It glows all the time & does not require charging, but it will require changing at around that 12 year mark.

Lume (luminova, superluminova, LumiBrite, etc.) are photo luminescent, meaning they need to be charged with light to glow.

https://www.strapcode.com/blogs/watch-movements-and-parts/which-watch-luminous-material-shines-the-brightest-in-the-dark

Decades. If I'm not mistaken, Superluminova and Seiko Lumibrite are pretty chemically similar and both lose less than a % of overall luminosity a year. I think it's a tenth of one percent with lots of sun exposure every year.

If the lume isn't exposed to the sun as much it'llast even longer.

Tritium is (from a glowing perspective) totally dead after 24 years and half dead after 12

Edit: tritium is 75% dead at 24 years and will be almost imperceptible at this time.

Tritium half life is 12 years so it's only half as radioactive at 12 vs new. At 24 it's 75% dead.

No. At 24 years it's 25% remaining (or half of the original half)

Not to be that guy… but

At 12y its 50% strength, at 24y its actually 25% strength (not 0). Its basically halves from the previous value. But it will go beyond the perception capabilities of the human eye… so it may appear dead around 24-30y ✌️

Hehe yes a half of a half. Pretty much usually at that point

75% dead then and practically useless.

Tritium was also used as a radioluminescent paint for dials & hands up until 1999, when the watch industry switched over to photoluminescent paint.

Luminova lasts about 30 years in my experience before really starting to degrade

I’ve wondered about that. I had a watch with lume way back when as a kid, we’re talking like the 70s, and I remember having to charge it and thinking glow in the dark was so cool. Or at least that’s how I remember it. When was photoluminescent lume invented, and when did it become common?

It looks like it started to be used in the mid 1990s. The article in the link below gives further information.

https://www.everestbands.com/blogs/bezel-barrel/history-of-luminescent-paint-on-watches

Hmm, I really don't think my memory is that far off. And I would have thought radioactive lume was even cooler (both my parents were physicists). Glow in the dark toys and such certainly already existed.

I was referring to photoluminescent paint, if you had a watch in the 70s I assume it would have been Tritium paint? I think generally though photoluminescent paint was used before the 1990s but not on watches

Reading this article more carefully, photoluminescent paint was invented in the 60s, which eventually developed into LumiNova in the 90s.

Shortly after the war, Nemoto started working on a non-radioactive compound and, in 1962, created a new phosphorescent material made of strontium aluminate... Nemoto’s creation has an induced luminescence, meaning it needs to be charged by a light source in order to glow. 

To make a long corporate story short, what Nemoto created came to be known as LumiNova after being joined by RC-Tritec AG, a Swiss manufacturer of Tritium luminescent paint founded in 1993.

Glow in the dark paint existed before the 90s, and, if my memory serves, and I think it does, was used in watches.