Cheapest way to protect silicone domes

[cpf user]

Aside from glass-dome LEDs (are there any cheap 3w ones?), what is a cheap way to protect the silicone dome of a 3w cree? No lensing is needed; a very wide angle would be best.

I've already ordered some chinese convex lenses of 13, 15, 18, 20 and 23mm, and will try siliconing them on, but there probably is a better way... some simple clear plastic covers possibly... but I don't know what they are called.

 

[Steve K]

I don't have much to offer... I made some glass covers for the Seoul Acriche 2 modules in a table lamp. The goal was partially to keep dust and crud off of the leds, but to also keep fingers off of the led leads and circuit board traces (they could be at line voltage levels of 115vac).

The covers were simple window glass, and I made the spacers from some aluminum stock. Not exactly pretty, but reasonably functional.

Before I decided on this method, I did look around for some domed covers. All I could find were some high quality ones from Edmund Optics, I think.. very pricey.