Is it possible to melt plastic optics while overdriving a LED?

[KillingTime]

Hi,

Quick question; I'm planning a custom build that will run 10A through a Cree XHP70.2 - for short periods - 5 seconds max. That's about 65W.

Properly heatsinked, an XHP70.2 will take 20A (design limit is 4.8A), but I'm wondering about the optic in front of it.

Has anyone ever heard of LED plastic optics melting?

I think I read somewhere that the high power LED lights use Alu reflectors for this reason, but many modern lights that have a high turbo (Astrolux MF01Mini, Emisar D4S) use plastic optics.

Thinking of using: 32.5MM PMMA Optical Led Lens 5 Degree.

Thanks.

 

[lightfooted]

I'm sure it's possible but not sure on how long it would take to do so. Polycarbonate melts at 155 °C which is hotter than you could hold in your hand. I mean it's beyond the boiling point of water soo...

 

[archimedes]

.... Has anyone ever heard of LED plastic optics melting? ....

It has been reported here

https://www.candlepowerforums.com/vb/showthread.php?327135-Peak-Logan-Optic-Melted

 

[stewdogg]

I had the optics melt in my FWC TiCu due to a faulty switch that turned the light on in my pocket for a while and melted/deformed the optics in the light. I never could get that light to work properly. Cool looking light, just didn't pan out like I had hoped.

I'm sure the short periods you are planning on having the light powered would help.

 

[KillingTime]

Thank you for the replies.

People that do report melted optics seem to run them for multiple minutes on >High or Turbo.

It will be fun to find out.

Regards.