Lately I have been experimenting with Glow in the Dark (GID) powder so I thought I would share my comments.
The old GID stuff is zinc sulfide. It has a short glow time, about 10 minutes or so.
The new stuff, I call "Generation 2", made from Strontium Aluminate, is a lot brighter at first, about 3 minutes, then the glow fades to very minimal. Sellers claim this stuff glows for 8-12 hours. Yes, it glows with a barely perceptible glow, for 8 hrs. I can see it in complete darkness if it is within 12 inches from my eyes. But it does not glow brightly for 8 hrs.
Sunlight, or full-spectrum light, or UV light, charges the new GID powder best. But it only glows brightly for 3 minutes.
I bought my powder from Ebay. I applied a ring to the outside edge of my flashlight lens so it would be charged whenever I used my flashlight (a 7-LED flashlight). It glowed brightly for a few minutes, then the glow was reduced to "very dim" after that. The very dim glow last another 8 hrs.
My point: don't be fooled by sales pitches. This stuff does now glow brightly for the advertised 8 hours or more.
Alternatives
- Radium is radioactive, but I'm not sure how harmful it is. Old dials and watches from WW2 used radium. And it can be hard to find. Watches on Ebay might claim to have radium, but may instead be zinc sulfide.
- Tritium is a liquid form of water that glows for 10 years straight. But a 1/2 inch ball of this stuff can cost $70us or more. Expensive, but it's there if you want it. Some rifle scopes use tritium tubes for the sights.
