What type of thermal adhesive used in fenix?

[big beam]

I'm going to mod some of my fenix(P2D) lights to warm (5A) tints.I just took a knife and scratched a little adhesive off and it seemed kinda waxy.Not like AA or AS.It also didn't seem to have a lot of adhesive quality to it,like an epoxy does.

Also,does the emitter have to be electrically isolated from the heat sink?And if so what are some of the adhesivs you guys are using?Fenix uses a bare emitter(no board).

One more thing,Where do I get some (3) 5A emitters?
Thanks,DON

 

[Al Combs]

I modded my P2D a few years ago when they first came out with Q5's. There is a small pedestal on the heatsink in the center for electrical isolation. The Cree XR-E is electrically neutral in the center. You don't have to do anything special to isolate the LED. Here are a few good pictures of the P2D heat sink.

I used plain 100% Arctic Alumina epoxy. Wintermute mentions in that post he used a mix of 75/25 Arctic Alumina epoxy and compound. Years ago the AA site used to say that was a good way to get a semi-permanent bond. I mention it because I suspect Fenix did something along the same lines. The color of the glue in the very center was different than at the edge. As you say the glue at the edge was slightly rubbery. Just a guess, but perhaps to prevent problems from the difference in thermal expansion between the ceramic and the aluminum.

Sorry, I don't know of an LED source. They shouldn't be too hard to find.

 

[big beam]

Thanks AC.Now all I need is to find some warm tints!
DON

 

[big beam]

Anybody try this stuff?http://www.dealextreme.com/details.dx/sku.4579
DON

 

[Al Combs]

If you do a forum search for sku.4579, you get several hits.

There is another option to Arctic Alumina. You can make your own thermal epoxy. Just put some fine grit Aluminum Oxide powder (5 to 10 micron range) in some ordinary 5 minute epoxy. A Google for, "Aluminum Oxide" will list several online sources. It's a common abrasive powder. An added bonus to this method is the powder never goes bad. You just have to play with the ratio a little bit to get the right consistency.