Being a “dive” light they may have glued the bezel with a special glue or more of it in an attempt to preserve/increase waterproofing. You might be able to just break it loose with oomph by using a strap wrench with a rubber strap (but one with a strong handle and pivot-rivets). If you can hold it securely with some padding in a vise, then use the strap wrench. You may need to use heat just as you would with some threadlockers…gentle even heating with any torch will do it, but don’t overdo it or else you’ll start to discolor the anodizing (and if it happens to use a plastic reflector and you overheat toooo much there’s the risk of damaging that). Maybe try again with the heat gun and give it a little more temp or time. Strap wrench is a godsend, though, much better than any pliers, and virtually zero chance of dinging up the aluminum.
Most of us hate glued threads but it’s getting more common now even on inexpensive lights.
Pretty much what I was going to suggest. It helps to clamp the head in a vise. I have seen some dedicated individuals here on BLF make shaped wooden clamps so you can really clamp it tight in a vise. Then use a good strap wrench on the bezel. Steady hard pressure may be able to break it loose. One of the threads said he blowtorched it for half an hour to try to loosen the glue and eventually it worked. Of course he really wasn’t worried about how it looked afterward, so as advised be careful with the heat.
This looks fun. You’re going to have one biazin UV light when you get it working.
I’m guessing some glue from the bezel got under there and is holding it. How about running an Xacto blade or some thin equivalent between the reflector and head to see if you can break it free? Be careful with prying as you don’t want to ding up that fancy reflector.
Working slowly and with small steps will be the way to go.
I'm still figuring out how to insert images. I'll try embedding. Also, Scientist, this is for the blue excitation light, I'm still unsure how I'll do the UV one.
I’ll update the images in the other comments I’ve made. I tried running a 0.2mm feeler gauge around the reflector, but no luck, could it be anchored with hidden screws?
I’ve just been reading this thread and absolutely loving the collegiate atmosphere and friendliness of that - plus it has multiple topics that are so interesting (to me, at least!)
So this is a gratitude post, saying thank you, and to encourage much more of these!
Okay, I've tested the results of removing the phosphor by taking some photos of a doll I picked up in Southern Mexico that happens to be sewn with a fluorescent green thread.
The doll:
My camera with a yellow barrier filter:
The two lights I will be comparing (on the left are the XP-L2's sans phosphor and on the right is a cree XT-E):
Here is an image with the phosphorless light:
And here is an image with the XT-E light:
You can see that while the phosphorless light is blue and probably fluoresces the thread somewhat, it is covered up by other wavelengths in the bandwidth, while the XT-E shows the fluorescent material with negligible background noise. So the phosphorless chips won't work for my applications. But I'm still glad JaredM suggested trying it, thank you, it was worth investigating.
Now I'll see about swapping out these chips for the XT-E's.
That is quite a difference. Any chance there is still some phosphor on the XPL2 leds that would contribute to the background light? If you have a UV light examine both emitters under UV and see what you see. That should make the phosphor fluorescence.
Very creative solution to the bezel clamping, great job! As I read, I thought of the internal screw and then I was hoping that the whole damn head wasn’t potted or everything glued solid.
Really enjoying the info and project/pics, reading up a bit on visible-wave fluorescence as well.
