One other point. A lot of people don’t consider that the “lens” on the light can really cut the % of 365nm light that gets through, so watch out for that - it is hard to discern the effect unless you have something that only fluoresces close to 365nm and not much higher. Obviously, a ZWB2 should sidestep that issue.
Can’t thank you all enough for the info.
Now comes the waiting as my parts arrive.
You’re welcome. Just make sure you’re handy with a soldering iron and you know how to remove and replace the LEDs. Make sure you have some thermal paste too. If you’re going to try the same light I used, be prepared to completely unscrew everything except maybe the side switch.
I’ve bought the tri led seoul led package but am not sure which host would be suitable.
Some artic silver thermal paste is on the way, i can solder so no worries there and i have a heat gun reflow kit if i hit any issues.
I’m guessing it fits one of the hosts they sell. Incidentally, I am not a fan of kaidomain - they masquerade as being in the Netherlands but my only order shipped from China and took over a month even with DHL shipping. I would rather use aliexpress.
Wow that is impressive. Which caterpillars fluoresce? Any pictures?
Someone up in this thread said that ZWB2 filters are difficult to find for odd sized flashlights but nowadays kaidomain carries a whole bunch of sizes (also for the S12).
I have bought and fried that exact board of UV leds by using a KD triple optic. A triple optic is the only thing that I know of that fits but UV gets absorb in the optic and overheats the leds and melts the optic 
. The only way I see to make this triple work is with no reflector or optic just straight out the head, might work with a glass convex lens like in some of the cheap zoomie lights.
If you wanna go with a triple or quad UV led light use something that already has reflectors like mavortium suggested.
I bought that on a whim. it was an impulse purchase. Something for the future toy cupboard.
Perhaps some useful information here: https://www.naturesrainbows.com/single-post/FyrFly-Convoy-C8-365nm-The-Next-Generation-Convoy
We built this light (FyrFly) and provided details as a service to our hobby. It has since been copied and is offered by other manufacturers. I prefer using RCR123 and a short tube even though runtime is shorter - just carry extra batteries.
General comments - on my personal lights I have driven the LG LEDs to 2.2A with no issues (yet). Have also built an s12, driving the LG LEDs @700ma. Also built a C8F triple, currently my favorite - driving the LEDs at 1.1A. The triples have the advantage of a much wider beam (good for minerals) than the C8.
That is what i am basing my build on, just adding my own stamp so to speak.
I’ve been quite badly bitten by the flashlight bug and now have loads of parts and bits coming for me to play with.
I will document my building experiences.
Joy. Almost all the parts for the UV turned up.
So after a brief study period, i took out the soldering iron and circlip pliers and within 20 mins i had a fully functional and very powerful UV lamp.
Just waiting for the UV filter to arrive but other than that it’s all worked out well with all the help you folks provided.
Ordered the extension tube as well for added run time and ergonomics.
I have nothing but praise for kaidomain, i have ordered quite a few bits (this torch building is a fun hobby) and have never had an issue.
I think what you’re trying to build is sold on the ali convoy store.
https://www.aliexpress.com/item/4000307648927.html
Unfortunately they won’t ship to the US or I’d order a few of them myself.