Thing is, toluene is found in what we call āthinnerā here, so why should we look for ānitro thinnerā if itās the toluene weāre looking for?
I have not checked the tint, but it is a random cool white led from the spares box, the tint is relevant if I would have known the tint that I started withā¦
Edit: FWIW, I checked tint anyway: pretty good actually, not ugly green, must have been a tint on or under the BBL before the dedome.
OK so the experiment with the solvent I had on hand didnāt work. Or should I say it was no better than hot gasoline or using acetone. So I broke down and bought some toluene and will try that and report back. Iāve got 50 of the SST-40ās showing up soon to experiment on. Iām making a TR-J20 for a member here and want to make sure that he gets 12 perfect de-domes in there.
On the bin that turned Rosy, that was quite a while back, I bought them on sale for cheap on one of the big aliexpress shopping days. That was back when XP-G2ās had just come out so for that time they were great but they wouldnāt be high bin enough for today, not compared with the S4 2Bās. Still I liked them a lot and wish that more of them would de-dome that color. They actually reminded me a lot of a nichia. The problem with ali-express buys are that you never really know exactly what you are getting. You might get lucky and you might not. So I havenāt bought from them in a long time.
Mainly because Nitro thinner apart from toulene also contains several other chemicals that removes silicone. And also because there have been reports of very little green tint shift.
The toluene took the dome off very clean. I did slice the dome off pretty close to the bottom before soaking. I didnāt boil the emitter on a hotplate. I used the boiling water instead like I would with gasoline. Itās VERY clean. Perfect. Now Iāll build a light with it in a while and report back on the tint. And Iāll compare that tint with the tint from the Hot high octane de-dome.
I use this re-flow block I made for my soldering iron :
I really havenāt had time to redo the experiment but maybe one/two minutes in total ?, it was more or less trial and error if it was still green I gave it some more heat
Great news thanks, twelve de-domed SST-40ās ? thatās going to be some kind of monster.
Good work! Luckily we have straight toulene to buy here in Sweden, so Iāll probably order some today. The thinner I use now is 80% toulene and 15-20% acetone and the dedomes Iāve done with it turned out too green. Iām suspecting that the acetone is the culprit as Iāve read that it might eat some of the phosphorus when used.
Been on a local supermarket a while ago. They now sell a āturpentine simileā whose composition is: C7 and C9-C12 alkanes in n-alkane, isoalkane and cycloalkane forms. Looks good to me, gonna get a bottle tomorrow. Half a litre for ā¬1.60.
Well, i hate to say it but Cree has changed the dome`s sillicone againā¦ā¦hard times for dedoming are comming folksā¦XPG2 and XPL are already affected but the change
Why does a perfect dedome work well?
If I understand DrJones correctly, even a flat dome should reflect less light back towards the phosphor than no dome at all. Reflection of perpendicular beam is down from 18% to 10% (6+4). TIR angle is the same. So total reflection with a shaved dome should be lower, producing better output and smaller tint shift. But numbers here, here, here indicate otherwise.
Can someone explain why is it so?
I have never seen a āperfectā shaved dome. So there is more lumen loss with a shaved dome because the top is no longer as smooth and perfect as with the dome on. I imagine there is still some scattering of the light because of the imperfections in the ātopā of the emitter. Not that I think a āclose shaveā de-dome is bad, because done properly it is still a good way to de-dome.
That was my first thought too. But @relic38has sanded the shave with 2000 grit paper. I think it should be OKā¦
Another thought is that in a perfect dedome thereās still a thin layer of silicone left.
Or maybe thereās some more fundamental reason.
Dunnoā¦
Just killed a LatticeBright āXM-Lā by driving it directly from a 3.5+V battery while submerged in white spirit. Gave it a few good zaps a few hours ago, can't say for sure if there was some apparent damage mostly due to my unwillingness to look at the thing while driving it.
Gave it another zap a few minutes ago, and it just died.
I have an old genuine XM-L next in line, but now I am in doubt with regards to submerging it with wires attached.
2013 manufactured cool white XM-L is enjoying a white spirit bath, with attached wires. I've given it some current, but the alu board doesn't even seems to get hot to my finger. Maybe the mia LatticeBright āXM-Lā was already ācookedā, it came from a friend's headlamp whose emitter I swapped.
Going to raise the battery voltage to increase my diver's driving current. :-D