Luminous Dials and Watch Value

Amik

Hi all!

I'm in the market for a good quality watch and some Bell designs caught my eye recently. They use an interesting technique to get glow in the dark dials: little tritium gas tubes.

http://www.ballwatch.com/global/en/technology/night-reading-evolution---51.html

Reviews I've watched says they start to lose intensity after 30 years.

In general how do such glow in the dark dials affect watch value later? I assume all radioluminescent paint fades after a few years? Better to avoid watch designs that use them too heavily?

Thirdfox

Hi Amik - tritium T25 (which I believe is what Ball uses) is an radioactive isotope with a half life of 12 years. It means that after 12 years the light intensity will be 50% of what it was at the beginning.... so after 25 years of owning the watch the tritium would only glow at 25% brightness... but if you're wearing the same watch after 25 years and was using something like superluminova paint it will be pretty worn by then too.

Just like superluminova paint - tritium gas tubes can be replaced. And replacing tubes might be easier than repainting lume (at least on my Omega they wanted to charge me for a new dial rather than repaint the lume on my Speedmaster which had an otherwise perfect dial).

One final clarification - they don't start losing intensity after 30 years - the tritium is decaying constantly - it's just that they only decay to 50% of brightness after 12 years (for tritium T25) - there is a Tritium T100 version too which will "last" 4 times longer since it started at 4x the amount of tritium/brightness so after 25 years it will glow like T25 at year 1.

hitemfrank

Just a heads up for you Amik, if you are looking at getting a Ball and want new, have a look at one of the IguanaSell websites to see if they have the one you want. There is usually a link on there site to get 18% off your order.

Amik

Thanks @Thirdfox for the detailed reply!