clear heatsinks

[Blue_Shift]

What materials that are clear (i.e. can be used for a lens) are good thermal conductors? Sapphire? Borofloat? Anything? And where can I get it for a D size m@g?
Thanks,
Jason

 

[Doug S]

Diamond is best but not likely affordable. Sapphire isn't bad. It is about 1/7 as conductive as aluminum. Do a search on sapphire plus CPF member McGizmo.

 

[Blue_Shift]

I saw his mod with the inverted LS and sapphire lens. I was wondering if there were any other options, and where can one get a sapphire lens?

 

[Slick]

Flat sapphire lens HERE. /ubbthreads/images/graemlins/smirk.gif

 

[Blue_Shift]

Thanks Slick!

 

[Blue_Shift]

I think the m@g has a 52mm lens and the largest at the above site is 32mm.
The search continues...

"High quality Schott Borofloat®
glass. This lens has outstanding
thermal shock durability."-flashlightlens.com
What does that mean? Does it mean it won't melt easily?
What about a polycarbonate coating?
Thanks,
Jason

 

[Steelwolf]

Thermal shock: Put a glass beer mug in your freezer till it's all cold and frosty. Take it out and immediately pour boiling hot water in it. That is thermal shock in the extreme. (The beer mug may shatter.)

This property is important for glass used in incandescent and HID lights, or anything where you expect it to get quite warm if not downright hot. Imagine you are running your 50W incandescent and you get a sudden cold shower. You wouldn't want your glass lens to shatter, would you?

Polycarbonate is a type of plastic. I believe the brand name is Lexan. It has very good scratch resistance compared to other plastics. It is very hard. But at the same time, it is very tough, which makes it less likely to shatter than glass (good impact and thermal shock resistance). However, it will melt and burn under extreme temperatures (though you shouldn't be reaching those temperatures in a LED mod) and doesn't have very good thermal conduction properties.

I think polycarbonate coatings are used primarily to increase impact shock resistance of glass, while still maintaining a high level of scratch resistance.

 

[Blue_Shift]

Thanks Steelwolf /ubbthreads/images/graemlins/thumbsup.gif

 

[dukeleto]

Hey Steel, what sacrilege for the beer mug, 'specially coming from a 'strine, mate /ubbthreads/images/graemlins/smile.gif


Olivier

 

[LEDmodMan]

Polycarbonate is actually quite soft. Acrylic is much more scratch resistant, but also much more brittle. This is why you see hardcoats applied to polycarbonate when used for things like eyeglasses, and also why the polycarbonate lenses that flashlightlens.com sells have hardcoating also.

Stock Mag lenses scratch very easily becuase they don't have any hardcoat whatsoever.