Castable acrylic?

[Lyndon]

I was recently given a handful of older Luxeon LumiLeds (a few years old) and I want to make an all around (360 deg) light for general use and as a canoe light. Since it needs to be waterproof, I'm thinking of either finding a similar light and modifying it, or building from scratch and embedding the LEDs in cast acrylic.

Question is will the acrylic be clear enough? I've never used this stuff and don't know if it yellows with age. The rest of the hardware/electronics I can handle just fine.

 

[kramer5150]

No first hand experience... I think acrylic compounds come in different varieties. Some have UV-safe chemicals mixed in to slow discoloration from the elements. tap plastics sells the stuff, as well as mold-cavity making supplies.

 

[LukeA]

It will be clear enough. It's what they use to make all those TIR optics.

The rate of yellowing will depend largely on how much direct sunlight the device receives, the less sunlight the slower the rate of yellowing.

I'm not sure you want to fully enclose the LEDs in acrylic. The LEDs will stay happy much longer if they're thermal epoxied to a piece of aluminum (preferably but not necessarily finned) that has surface area exposed to the atmosphere for cooling.