A Perfect Dedome?

Even so, the hydrocarbons used are likely to be very similar. By trying different octanes, it gives a clue as to which chemical is doing the job. That's why I mentioned Xylene earlier. That's a component of gasoline with a higher octane rating. If folks find that higher octane gas is more effective at dedoming, then the next step is trying Xylene or other high octane components of gasoline. Toluene is also worth checking out.

Folks should be careful around gasoline and its components, not just because of the fire risk, but also because components of gasoline are made up of aromatic hydrocarbons that have strong links to cancer. I'd avoid direct contact with skin and would have good ventilation.

Interesting, good input. I was so careful in handling the dedomed LED. I know I accidentally hit the domes all the time with a finger, knuckle, etc., and usually go over it with alcohol before buttoning it up. It just looked so vunerable, naked and all - now don't get too excited .

FWIW.

I dedomed an XML at this time last year and put it in a light that gives it around 5A.

I've not used anything to coat it and there is hardly any "goo" left anywhere.

It probably has around 100 running hours on high since then and it put exactly the same amount of light out today as it did the day I dedomed it.

To put that into perspective I think of it this way. By the time it burns out I'll have at least xml2 or 3 or even 4 to chose from to replace it.

So I think that as long as you do not mechanically damage the wires or phosfor you and your led will be fine.

Is there an alternate to petrol (gasolene), I cant keep it here as the wife has a problem with it similar to the problem I have with alcoholic beverages.

Thanks ChicagoX.

Going along the lines that somethings that works in one place and not another, we have flyspray here that says on the instructions on the can that it will kill spiders in the state where I live but apparently will not kill spiders in the state next to us. I have noticed lately that there is a lot less spiders here. I'd say that they are all moving to the next state (NSW).


What about its components like toluene and xylene? You should be able to find those at your hardware store. Whatever you don't use for LEDs you can put into the gasoline tank of your vehicle.

-I'm pretty sure that its irrelevant. I just included the octane rating as a fun fact. :D

-I left an XPG in gasoline for three days, didnt harm it.

-It should be off the phosphor because it will block/diffuse the light. If its not completely gone, give it more time.

-I used a 0.2cl glass for schnaps, about half full. So I say the amount does not matter. But you have to cover it (foil for example) because otherwise it will be gone after half a day.

-never used LED Seal and neither did anyone else in Germany. SST90 has air between dome and phosphor.. I think putting anything onto the phosphor would have negative effects on the throw because you'd increase surface area again.

-surface matters.

-I didnt clean it because gas is fugitive.

The tips about being careful with gas.. seriously? Of course, dont drink it, but you will be in closer contact to gas when you use a chainsaw, lawn mower or just fill your car.

Thanks leaftye. If I put the led's in the fuel tank would they not block the fuel filter up. Do leds act as some sort of octane booster? I'm not sure that would work for me as I have had to buy a diesel for the wife which I dont think matters about octane rating. Does it matter whether there the very cheap led's or do they have to be Cree?

I have some xylene, or actually, xylol,though I’m not exactly sure where, but next time I come across it I will try it.

I have it because it is a thinner/cleanup for hammered paints. I can tell you that it is NOTHING like paint thinner, lacquer thinner or acetone as far as how hazardous it is.

Fumes will F$## you up - BAD.

and, don’t get it on your skin either. I regularly soak a paper towel with any of the other solvents and rub my hands clean of whatever I’ve been applying.

Try that (or even lesser an amount) with xylene and your skin will begin to tingle, then it goes deeper, and it feels like the limb fell asleep - then it starts to ACHE like someone stomped on it. Then you feel real sick.

ask me how i know.

I bought a mask just to work with the stuff, because I like hammered paints - but unless you HAVE to use it, stay the hell away from it.

Hmm… I have a can of Italian made gel paint remover with a really cute name “DYNAMITT 46” (methylene chloride based) and that thing eats trough everything (eats latex gloves for breakfast) perhaps it would work well for dedoming too…

it will probably lift the paint off the dielectric layer and might even lift the whole layer from the board

This kind of stuff is why I’ve kept the emitters I’ve poofed :wink:

Anyone notice the fourth bond wire? The one that looks like it’s going between the negative and positive substrates? Look near the top edge of the silver circle. I have no idea what it does, but it connects to something really small on the positive plate. I broke it and the LED is still working. Just curious.

Pretty sure its the ESD protection.

Well, I got it in the HD2010, finally. Had some issues with shorting under the LED. Toughest reflow I’ve done yet.
Anyway, Here are the numbers:
HD2010, Dedomed XM-L T6 1A, East-092 (DD) at 4.4A, Sanyo18650ZT at 4.2V
Output: 1022 lm at start, 994 lm at 30s
Throw: 75kcd
Not too bad for an XM-L T6. Tint is a greenish warmish cream, with a nasty uneven hotspot. Still has decent spill.
Not sure why the hotspot is uneven yet. This particular HD2010 never was particularly smooth.
Still have a darn short on the reflector, modes do not work so it must be on the negative side. Silly HD2010 design |(

Ahh, that makes sense. Guess I should be careful with it then :wink:

Is gasoline really that easy? Just drop your led in a glass of gasoline, cover, come back a day or so later… perfect de-dome?

Yep, it’s that easy. No magic involved, just drop it in and wait. I never left one in there for less than over night so I can’t say what the minimum time is, but I forgot one for about a day and a half and it was fine. Sometimes you have a little silicone left around the wires etc… I just left the extraneous bits that weren’t on the phosphorus. One time I carefully pushed some small bits off with my pocket knife but I don’t think you need to. Most people have gasoline in the garage and with gas at four bucks a gallon you could do thousands of de-domes for a fiver.

Hey guys on my earlier comment about where have you been I was trying to kid around a bit. I should have put some kind of smiley in there and didn’t, so here it is!. :slight_smile:

Oh sorry, didnt' mean health risk, I meant long term issues with the emitter. I'm thinking this: take it out of the gas, solder the leads - poof! Or leaving the gas on to evaporate, maybe it would leave a film of chemicals behind, causing bad effects weeks/months later? -- that kind of effect. By "care/treatment", meaning clean-up, spray treatments (LED seal or whatever). But what you are saying nothing is needed, and after one year, no long term effects. This is getting better and better! Looking back now, why did I go so off track? This seems to be the best and easiest way by far, at least for me and many others I assume. Now it seems like the only issue is deciding whether to do it or not - yes there's some risk of damaging a $10 LED (plus s/h) you waited 4 weeks for (the risks though seem less than I thought), but you also have to decide whether the smaller tighter beam, less light in the flood, warming the tint is worth it for the double effect on candelas. Making that decision is easy easy once you understand all the pros and cons.

That's the 'planned obsolescence' fuse.

Well then, mine will not be going ‘obsolete’ by itself then :smiley:

Putting a XP-G in gas oil for 24 hours works fine.

The dome did not fall off by itself though. What happened was that I thought it had not worked so when I took it out of the gas oil i poked the dome with my finger to feel if it had gone soft at all. It had not really but it just slid off!

I then sprayed the die with electro cleaner for a few seconds and that removed any gooey stuff that was left.

Initially worried that I might have broken the bonding wires with my thick fingers I hurried to test it out with a battery and it works.

Thank you very much to the OP and all others who have contributed to this thread and the knowledge we now have. TY! :-)