Funny you mention that, I have done that many times during sailing boat races at night here in Holland, but that was 10 years ago. At the time we had big maglites for that (very useless), and lead-acid battery powered big halogen lights, those were great, but lasted 7 minutes on a battery. And now we have this in our pocket 
. But still an aspheric would be even better for buoy-searching because of the total lack of spill
djozz - I don't mind at all and it's not off track, that's the next phase, what are the results and what do we do with these de-dedomed emitters? 
This is probably the thread to note that
I’ve wasted >$100 trying to dedome mtg2s
You CAN shave the dome off with a razor, but the phosphor is thicker than you think, and the throw gains are not as high as with other emitters (neither are the output losses).
Petrol - no go, all the phosphor will come off the center of the emitter
Same with acetone.
If you try the ‘off heatsink heat method’, the dome will bubble at the emitter and pull the phosphor off…and it takes a @#$% load of power to do that…these things can handle some serious current…
100% agree. This is the only kind of thrower I need - tight aspheric beam to avoid back scatter on the water.
In NY state, the water is often much warmer than the air (particularly in late summer and fall). The amount of back scatter at night is ridiculous. you can’t see anywhere if there is any spill.
But, if camping on a small island, this makes for quite a surreal experience - fog rising all around but no fog on the island - and there’s still a cold/clear upper atmosphere and so many stars visible 8)
GUZZALEEEN!!!!!111one
I wouldn't have tried this on a U2 otherwise, but this one was dead after a reflowing screwup, so no loss if it didn't work. Guess what? It works now. It was dead, completely dead. I'm sure it's not 100% healthy, but light comes out when you put power to it.
Nice build and numbers. What light/host are you using to get those kind of numbers?
That is sad, sorry to hear that you ruined many of those . At least by mentioning it here people are warned not to try it themselves.
It is this light from dx, I think it is a good deal, one of the few large reflector lights under $20, it is not too heavy, but there is enough aluminium near the pill and the body is one piece, good for heat spreading. The reflector is also aluminium, had to file some away to stop it touching the solder joints of the led-board.
But I seem to be the only fan of it, the problem may be the 'coffee' colour, I don't like it either. I use it as a test thrower because it is very easy to mod. It has its third driver now and its fourth emitter 
, and I guess the current set-up will also not last long...
Looks a lot like my Small Sun ZY-T619 here which I got for 50% off, like $13. Been on my list to play with, but no time. Thought it was an X9 clone, but not quite the same quality, bit disapointed.
.
Looks very much like it, but there are also quite some differences (I looked at pictures at manafont.com), the most obvious one is the body of that Small Sun is not one piece. Anyway, it is the reflector that does the job .
Successful gasoline de-dome on XP-G2, as well. Working just fine at 2.8 amps. Previously mentioned resurrected XM-L2 U2 working fine at 3.8 amps.
I'm sure there are tools made for this, but I don't have one, so... I made a plastic pointy-thing from the tail end of a zip tie, cut to a very very fine sharp point. Use that to clean away any of the crumbly bits of silicone off/away from the dome. (I used a metal knife on the assumed-dead XM-L2 in the earlier picture, hence the nasty scratches on the substrate - no more of that, thanks.)
Has anyone tried kerosene on these?
If somebody wanted to make a blue one, on purpose, what's the best way to get rid of the phosphor layer?
Finally got around to cutting the grass and since the mower needed gas the XRE started it’s bath late today. It’ll probably soak until some time Thursday morning.
What kind of current are you thinking? Or have you already done it?
The ones I've done in gas only need 3-4 hours, even without giving it a headstart by lifting the corners.
Well, I pulled it out of the dunk this afternoon and there wasn’t any sign of remaining silicone on the ring or the mount. Used bent needle nose pliers to pull the ring off (green stuff adhered on bottom of the ring, spots show in the pic below). Sprayed it off with some electrical contact cleaner to dry it off fairly quickly.
Results
Applied power for a just a brief moment and it still lights up. So I guess I’m now 1 for 1 on a successful de-dome.
Perhaps swapping out the XPE in a single mode SK68 to see what happens is the way to go.
A reflow over to a copper sinkpad and into a P60 drop-in with a new driver would be nicer. Will 2.8A be too much, or should I just limit it to 2.1A? Suggestions on how much amperage to reasonably push into it?
There's no SinkPAD for XRE's?? For XRE's, limit is about 2.2 - 2.4A or so, I've used 2.45A for A60's, maybe not much more than 2.1A. I'm using XP-E2/SinkPAD's now in A60's at 2.8A -- Match's tests still show a rising lumens output at that amperage, but not rising much...
Good question - I think the MTG and XML pads are too narrow, and Sinkpad doesn’t seem to list it.
depends on your XR-E. people here have gone north of 2.5A with white R2s, and that’s without copper PCB.
I can say from experimentation that the green ones are not as robust. Also, the Vf on greens seems to be much higher than white - ie I can direct drive a green xr-e off one CGR18650CH and it won’t eat over 1.4A because of the Vf, but that doesn’t seem to be (as much of) a problem w/ white xr-e
I sent an XR-E R2 to Match and there’s a graph of his test on here somewhere…
edit: also, I flowed an xr-e to a copper sinkpad, and w/o an good tests to back it up, I’d say its a toss up between using that and an aluminum pcb (w/ proper xr-e solder pads), because you lose so much contact area on the center pad.
nope, I asked them directly.
and since it isn’t something they already make, they won’t mix it into an order like they did with out xml/xpg orders.