My Seoul modded G&P 1W turning blue after about 20 seconds...

[KDOG3]

I don't get it. I checked and rechecked for shorts, even put a copper shim between the emitter and the heatsink. Tried using a little thermal epoxy and alot of thermal epoxy, no thermal paste in the heatsink/driver chamber to filling it up with thermal paste (AA) and still after about 20 seconds it starts to turn blue indicating that the emitter is over heating. And this is with the 1watt driver! Blew 2 emitters trying to figure it out. At my wits end here. Anything I'm missing? Got another 1W drop in and emitter on the way, if it doesn't work this time, I'm done with trying to mod those things. I had good luck swapping the emitter in a KL1 head, maybe I'll go back to doing that...

 

[IsaacHayes]

Remember the slug is positive... but I don't think that would cause it to go blue... Unless it had a mild short and just added more heat to the LED causing it to over heat that way.

 

[Nake]

Is the reflector possibly touching the pos and/or neg connections. I put a Seoul in my Huntlight FT-01 and upon activation it turned a fierce blue and dimmed in a few seconds. I backed off the reflector and it was ok.

 

[KDOG3]

Well I carefully lifted up the emitter and decided to glop a whole mess of thermal epoxy under it to see if that would help, seeing as I had nothing to lose. It seems to have helped, I left it on for a good 5 or so minutes and the tint barely shifted. Its in a C3 and I can feel the head get a little warm after a while. Maybe after the epoxy fully cures, it will be even better...

 

[cmaylodm]

You don't want a whole lot of thermal epoxy between the slug of the LED and the heatsink, just enough to ensure that there is no electrical conductivity between the two. While thermal epoxy is more thermally conductive than most other things, it still isn't all that great. Also, if you prepared the surfaces correctly and mixed the epoxy well, it's going to be near impossible to remove the emitter without destroying it. At least that was the case when I used Arctic Alumina Epoxy.