Comments by "geodkyt" (@geodkyt) on "Taiwan's Retro Gas Piston AR: the Type 65" video.

  1. ​ @OlMrEllis most consumer products. But watches, clocks, and military items like compasses and gun night sights like this tended to use radium through the 1960s (especially outside North America and Europe), and even then they switched to tritium based paint (which was then phased out in most places in the 1990s) or tritium vials. As for radium paint losing effectiveness since produced, that isn't due to the radium losing radioactivity - the half life of radium is 1600 years . The issue is the constant radiation bombardment of the phosphor (the stuff that actually makes the light) causes the phosphor to degrade. You can refurbish those sights with new phosphor paint - silver activated ZnS paste (and some varieties of "photoluminescent" phosphor paint) will happily glow with the Alpha and Beta decay the underlying blobs are still emitting, if the original paint is intact. And it's no additional hazard, either - you're nor adding new radioactive material, after all. The sights are emitting pretty much the same amount of radiation they did when new, only the paint that turns that into green glow has faded. TL;DR version - old radium watch dials and gun sights (like this, or guns like the Galil, Yugo SKS, etc.) are still something you don't want to lick, or grind with your Dremel, etc., even though they don't glow any more.
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