I did my first reflow work today and discovered that it was so easy that I had to report it here.
I reflowed 5 bare nichias to 16mm stars for XP-G’s in less than 5 minutes including a function test of each. And the result is excellent.
A year ago I bought some solder paste but have’nt really used it:
http://www.dealextreme.com/p/lodestar-soldering-paste-50g-4711
It had hardened some (solder paste should be kept in a refrigerator) but I managed, with tweezers, to put small blobs of it on the stars solder pads.
Then I pressed a Nichia into the paste minding the negative mark in the corner and placed it on the cooktop in the hot zone. 5 seconds later the solder paste bobbled, the solder went shiny and the Nichia sat itself into the correct position and I pushed the star away from the hot zone - finished.
The hot zone on the cooktop was pre-heated (level 2 out of 9 levels) to a little over 200 degr.C (checked with an IR gun). One of the samples got more heat, about 300 degr.C and reflowed in about 2 secs but it works fine anyway.
This cannot be more easy.
No pre-soldering, no soldering iron, no heat gun.
Now the difficult bit is to decide which lights should receive my first Nichias.
Nice work! Makes me wish I had a glass cook top. ;) I just hold my soldering iron under the star.
Nice work. Glad to know there is an easier way to do it.
Well done! And thank you for sharing this neat little tip.
great tip. I just moved into a place w/ glass range and never would have thought to try it…
Yet another way to get our wives torn up a us! 
I can hear it now - “Get that !@^&$ off my stove! Look, you got solder all over the place!”
Thanks for the tip. I have been using a heat gun to reflow and burn myself every time. I'm glad those glass cooktops are good for something besides cooking with them. LOL
Nice work and a cool (hot) idea, sixty. I reflow on a burner rangetop with the MCPCBs on top of a Mag heatsink on top of a cookie sheet. It takes me about 15 minutes to do just two! I’ll have to try out the glass rangetop method at a friend’s place.
neat! I did my first on my electric hob (one of the twirly ones) and it was just as easy.
That was easy. I've always thought those ceramic tops were all induction-based. Considering you didn't fry your emitter with the huge EM induction - apparently they're not. 
I did the same thing on my triple XM-L stars. If you think XP-Gs are easy wait till you try XM-Ls, all you have to do is set it in the general area and pops into place.
Just reflowed my first LED!! A neutral XML onto my quark AA2 tactical star. Used a heat gun and it took about a minute to swap. Wow! I didn’t know it was so simple!
I know I didn’t use the ceramic top, but it was thanks to your thread that I had the courage to attempt it (and I used a heat gun which I also obtained from this thread)
Thanks again fellow BLF’ers!
Another easy method is to use a simple nonstick pan on a regular stove. I’ve had good success with that.
Now this I can use. Thanks for the tip.
No wonder people think we're nuts, we're practically frying these things now. What next, olive oil to improve heat transfer? Or some extra flavoring with bread crumbs?
I recommend using an old pan or at least one you don't mind messing up. All it takes is one little slip to get lead on the cooking surface which would essentially ruin the pan for cooking. Also, it doesn't take much to damage the non-stick coating on a pan. A couple nicks with metal tweezers is all it takes to get it started.
Can I get fries with that star?
Those look perfect. Nice work man.
You guys are great !
I’m used to improvise at my photographic sessions and it’s nice to see that I can improvise at my first modding attempts.
- use the oven to bake flashlights body
- use the cooktop to reflow emitters
What’s next ? :bigsmile:
I got no excuses left not to start modding anymore.
Glass ceramic, electric spiral stove?
What about glass ceramic INDUCTION stoves?
I doubt these work as they heat up an object not the stove itself. The stove does not produce heat, the pot/pan does.
And the induction is going to fry the emitter I think even if placed on a turned on induction stove with an old pan to provide the heat.
Thanks for sharing