A Perfect Dedome?

i wonder if soaking it in goo gone will work too?
goo gone

I tried it and it ate the dome :slight_smile: ill try it again to see if it works like my first attempt

I expect it would, but i’m surprised the phosphor survived!

your led will only work in the uk, if you try to travel with it, it won’t be compatible with batteries and dark environments designed for the rest of the world :smiley:

Nah…you just have to hold it in your left hand for it to work. :wink:

Success! I had cut this one down and polished the remaining dome.
Bare emitter Lumen results: 700mA drive current, XM-L T6 1A
Original dome unchanged: 276 lm
Cut down and polished with 2000grit: 200 lm
Gasoline dunk, dome fell off: 264 lm
This one be going in my other HD2010 on copper SinkPad to compare to the XM-L2 T6.
The tint looks slightly greener than before. Definitely warmer now.
Hmm, my vision seems more affected than usual by the emitter at full power. Keep your eyes safe. I need to get some oxy welding glasses…



This stuff is great. It not only protects the phosphor coating after dedoming, but also prevents reflector shorts in situations where an insulating disk cannot be used.

Me likey.

Thats because the light is more concentrated now. See laserpointers..

I wonder what chemical in gasoline is doing most of the work. They do sell Xylene in the hardware store. If it doesn't work, then dump it in your gas tank for a slight octane boost.

Can you spray it into a cup and then apply with small brush, or a dropper? How easy does it flow out before it's cured?

Haven’t we been saying to use gasoline for months now? Where have you guys been?

+10, Excellent!

Honestly, I've never tried. The spray emitted from the can is pretty thin, as is a single coating from same. When used as an electrical insulator, I make two or three passes.

A year's worth of use has left me with just under half a can left, FWIW.

Even with the Internet it takes time for word to get around. I’m here daily and only recently heard about it. I don’t read every single thread every day.

I'm sure you're right, but it's been difficult to find for sure what the best method really is in all these postings and threads with the mix of successes and failures. Think we need a shared googles doc just for dedoming, or some way of summarizing the experiences. The big thread on dedoming is just way too big to get a bottom line answer from. I'm still not sure exactly what to do with the gasoline method. If you could reference threads/posts with specifics, that would be a great help. My questions with gas:

  • does the octane, content, source of the gas make a difference?
  • 12 hrs min time, but ok if longer?
  • Is all the silicon remnants supposed to be completely gone off the LED? I found it wasn't and needed to be pushed off - maybe I did something wrong?
  • can you do just minimum amount to cover the LED dome for the soaking, or should you use a full jar/can of gas? Does it matter?
  • the LED Seal stuff sounds good. Is everyone using it? Any side effect like measured output drops?
  • should the wires be clear of the gooey stuff as well or only the surface matters?
  • should the LED be rinsed/cleaned after the gas soaking? How? I used isopropyl alcohol - seemed ok, anything better?

When I used acetone, I thought the rule was 30 minutes, then that's it, good to do. But it didn't work out that simply. There are several ways of doing the heat method, but again, seems like details are lacking, or skills/knowledge of what to look for are not there. I think what happens is if you have success with a method, you stay with it, so if someone has 100% success rate on a heat method, why change? But for someone trying this for the first time, it seems like the gas method is the best way to go perhaps.

Also with the chemical approach, I think everyone is a little apprehensive about potential damage and long term effects, follow-up care/treatment, etc.

I think there’s some confusion about what octane rating means.


iow, 92 octane from one supplier might be a different cocktail of hydrocarbons than from another…but they should ignite at very nearly the same conditions

For the record, I did mine in 87 octane, and it was fine. I’m confident the octane is not what’s eating the dome.

I just tried using silicone conformal coating on the de-domed emitter and the results are troubling.
Dedomed XM-L @ 700mA (more details in my earlier post)
Before coating: 264 lm
After coating: 252 lm
It’s not huge, about 5% loss. Worth noting anyway. Since the LedSeal is silicone based, I’m thinking it would have a similar effect. Maybe spraying a very light coat is the best way to do it.
Is the coating even necessary? What happens if you leave it?

I'd give up ~5% to know those teeeeny little gold wires were protected.

I dunked it in gasoline again for a few minutes and it recovered some of the loss; back to 257 lm.
I agree that having some protection is good. I was more concerned about the phosphor layer browning, but I read somewhere that it’s coated already.
The bond wires are made of gold, so they will not degrade in open air. Physical contact with them is not good, and LedSeal isn’t going to help with that.