UV inhibitors / epoxy

[stevoman]

hmm, I think I'm getting confused...

Okay, so Strontium aluminate is primarily "charged" by UV light...

Most epoxies seem to have UV inhibitors to prevent them decaying or yellowing...

Even military grade optical epoxy seems to have high attenuation for UV wavelengths.

Am I missing something, or is there a better base to put this stuff into?

 

[Skylighter]

Our experience over the years has been that UV filters in the medium are almost irrelevant for high loads of phosphorescent pigment. If you are using 15-20% by weight of pigment, than the percentage of UV filters are simply not enough to cause a problem. On the other hand, if you are going on cheap and are loading at 2% (which is the standard retail load), than UV filters really hurt performance.

As for the ideal medium, I think it depends a lot on what you are trying accomplish. Soon, Glow Inc. will be releasing a new medium option that has the potential to replace epoxy as the thick medium of choice.

 

[stevoman]

Ahh okay, thanks for the info.

I just saw the specs for Norland 61 (which I have seen recommended as the best optical adhesive for these kinds of applications), and noticed the low transmission of UV

http://www.techoptics.com/pages/Norland Optical Adhesive 61.html

(see spectral transmission graph at the bottom)

Granted, this is a UV curing adhesive, but it's the only spec sheet I've found for that type of product.

Probably there's enough short wavelength visible light that does pass in order to charge reasonably effectively.

As another point, has anyone had any luck mixing glow substances with casting or doming resin? It looks like clear polyurethane or polyester resin would be ideal (though it also seems to generally have UV inhibitors to stop yellowing)

 

[Mr. Blue]

Soon, Glow Inc. will be releasing a new medium option that has the potential to replace epoxy as the thick medium of choice.

well heck yeah!!!
if it moulds, I will buy it in bulk!

 

[lotsaluck]

This stuff works great... http://tb.smodev.com/tb/uploads/Crystal_Clear_200_Series_(202,_204).pdf

 

[Oznog]

Well there's all sorts of UV.
The longer, lower energy UV in blacklights and UV-LED flashlights is more than able to charge this stuff, that's UVA and might not be blocked. The higher energy wavelengths (UVB,UVC) are the ones more capable of causing damage and those will definitely be blocked. So there may be plenty left in sunlight to charge the pigment, and a blacklight would have the same effect. I'm not sure myself though where these materials start to block UVs.

 

[Skylighter]

That is a very good point and would explain why some UV filters prevent charging and others do not. I never even thought about the fact that the filters are probably only filtering UVB and UVC.

 

[eyeeatingfish]

So GID powder is charged by UV light... Does this mean that certain types of light wont charge it at all or just dont charge it as well? I know a general LED flashlight will charge i, but I have to say that nothing charges it like the sun...

 

[KrisP]

From my experience the sun is the best, then UV light sources, then incandescent globes, then white LED's.

I haven't tested colour LED's or fluorescent tubes.