dome fell off, taking part of phosphor with it -- any glue suitable to stick it back together?

Flashlight Modding and DIY Parts
1

Mostly just curious.

$3.50 Nichia, 20mm star (no longer available from the place that sold them)
Worked fine for maybe an hour total, replacing a cool white stock.

Added a thin smear of Arctic ceramique (none on the original), no other changes.
Suddenly, it’s crazy blue-white with a yellow off-center spot.
Yep, the dome had fallen off into the reflector, with half of the phosphor.
fixing a broken link EDIT

It’ll be easy to replace; I’m curious about a glue to stick it together.
Else I might try a dab of glow-in-the-dark paint.

2

You could try optical grade adhesive. Personally I would try just placing the adhesive around the edge of the dome instead of on the die.

3

I think its FUBAR

4

once the phosphor separates the emitter is shot

5

If you have a heatgun, you might be able to just remove the emitter and then reflow a new one onto the star in-place.

6

FUBAR. You mind as well pull all the phosphor off and make a blue beam.

7

Checked with the $40 spectrometer from spectralworkbench.org (highly recommended)

This damaged emitter puts out a peak in the 300-400-nm range, significant eye risk. It’s going in the “kids don’t use this at home” bin.

8

So it might be damaging to your eyes in the long run. The sun is too. I was suggesting it as a alternative to getting a dedicated blue emitter, or as a alternative to throwing it out. GITD objects charge in seconds with that wavelength.

9

Good Call! Any chance of getting a refund from the seller?

10

Use it as your UV light. People actually try to get <400nm when buying UV. Most cheap ones don’t go so low.

11

Wooha, that's way into UV territory.

Thanks for the suggestion on the spectrometer. :)

12


is how it looks using the spectrometer
(the spectral workshop software is still intermittently buggy, not saving properly right now, so that’s a snapshot at photobucket)

> So it might be damaging to your eyes in the long run. The sun is too.

*My opthalmologist, about eyes, says the same thing my dentist says about teeth:

_You only need to protect the ones you intend to keep using.
_*

13

That's cool. I will be reading up on that kit you mentioned soon. Would love to have that.

I sure wish we had a high CRI phosphor recipe and way to adhere it to a die. Maybe that will be the next BLF frontier.

14

Why don’t you go ahead and get that going? I’d love to be able to do a remote phosphor layer with deep royal blue LED’s.

15

I’ve personally reglued a failed XM-L2 dedome attempt with plain old superglue.

I lined up the bond wires while placing it back on the emitter with tweezers.
Turned the light on to check phosphor alignment. ( Moonlight mode is awesome.)
Pushed the dome down with a small flat object not to dammage the dome further.
Turned the light off.
Applied glue to the base of the dome. ( Just enough to cover the base of the dome.)
Held it in place for 2 or 3 minutes.

I’ve been using this light as my EDC for a month since I did this and it’s still holding and this light is pushing 3.3A at the tailcap measured with stock ( read restricted) DMM leads.

16

Did your failed XM-L2 dedome result in phosphor stuck to the dome?

17

Yes

18

Thanks for the info, viperbart.

I see no reason why it shoudn’t work, but it should have reduced brightness due to air pocket (die - air pockets - phosphor - dome - air) and some light will be refracted/reflected at that point.

Maybe not noticeable by eye though.

19

The beam is not perfect anymore, that is for sure. If the output is diminished, I couldn’t notice it. What I did notice was the electric purple color when the dome came off. Lol

20

Cool. Do you have an idea what level of current you've been running through the repaired emitter?

Welcome to the forum viperbart :)