A Perfect Dedome?

I haven’t actually done anything with it! It was one that I pulled out of a light which I am replacing with an XM-L2 U2 so I figured I would just use it as a practice one. I will get around to seeing how it looks in something I suppose. I really want to do a de-domed XP-G2 in an aspheric host.

Am I right in thinking if I prefer the whiter end of the neutral range I should get something like a 1C tint XP-G2 to de-dome? What sort of tint would that go to after de-dome? Like a 3C or warmer?

Also I used 2K thinners and it took about 30 mins. Didn’t appear to have any effect on the phosphor either.

Someone here has measured color temp before & after - I'm thinking it's got to have been texaspyro - iirc he measured about a 1200-1300K shift downwards. Quite a lot more than everybody would have guessed. For a thrower (and why else would you de-dome?) where color rendering is less important I don't think you can start with one that's too cool. 7000K would give you a de-domed result of 57-5800K or so? Still a lot warmer than typical for a dedicated thrower.

XML2 U2 '1C' with dome...

and XML2 U2 '1C' without dome...

Thanks for your reply DBCstm. I was just able to get $2 worth of gasoline and I think I’m set for many many emitters.

Nice beamshots comfychair, it’s good to see them again. One thing I just wanted to point out was that since the C8 reflector is bigger than that of a P60, they can’t be used for comparing beam angles, right?

Right, color temp only. But they started as the same bin/tint LEDs from the same reel.

Awesome, thanks.

Hi,

How much gasoline do you get for $2 in Seoul…. like a thimble-ful :)?

:bigsmile:

About a liter of regular gasoline. Just under a liter for premium though.

The high gas prices only affect the poor and middle class though, the rich still drive their gas guzzlers like there is no tomorrow.

Dedoming shifts XML color temps down by a factor of 0.65 to 0.75

Thats exactly the tint I want my aspheric XP-G2 to have. Thanks!

You can monitor to see if the dome falls off or is loosened, maybe 2-10 hours, or you can pull it out in 2-4 hours and poke it gently to see if it will easily be pushed/flipped up and off. Lately I've been doing the shorter time (2 hrs), and carefully flipping it off, starting from the side opposite the wires. Overnight takes the guess work out of it. Most of the time now I see a bubble forming under the dome, indicating the dome' seal has been compromised. At that point it comes off pretty easy.

Gotcha. Is there a sweet spot in terms of hours under gasoline, or is there a greater probability of success with longer times?

Damn, it’s like 150-170 cents per litre for premium here in Melbourne.

There's no such thing as 'too long', just leave it in until the dome floats off on its own. If you lightly score the dome with a razor just enough to break the outer skin it can happen in as little as 30 minutes.

Good point comfy on the dome cuts - gotta try that on my next de-dome.

Yeah, all our oil is imported… very pricey. :~

Thanks guys for all your help, I’ll try dedoming once my XM-L2’s arrive. :smiley:

anyone have any longevity issues after dedome?

Hey Djozz, that there flashlight wouldn’t be utterly useless to me!!!

I did my first de-dome last night on a Crelant V21A XM-L. I don't have the know-how to remove the whole LED so I just unscrewed the reflector so the emitter was sticking out the end of the light and submerged the top 5mm or so into a shot glass with a little gasoline at the bottom. The dome slid RIGHT off this morning EASY as pie and darn near perfectly.

My only question is how do I get the gasoline smell off?

I ran the head very gently under water to rinse off some of the gasoline and let it sit out all day to fully dry but it still wreaks of gasoline since the metal was submerged somewhat. Obviously I can't really use any chemicals or anything get the smell off...what about just leaving it out in the sunlight? Would that be bad on the bare emitter?

Please use isopropryl alcohol - rinse it - works well with a squeeze bottle. The alcohol is relatively cheap at drug stores (maybe supermarkets too). I use it every time, works well. Actually I use it a ton on cleanups, solder flux, etc...