A Low-Cost Optical Glue Curing Method - Page 1
Forum section: electronics / projects

author: CaptnYellowShirt
author_rank: Frequent Contributor
timestamp: May 22, 2014, 02:03:20 pm
content: I've had a need to use some optical glue in a project of mine -- specifically Norland 61. It's great stuff, if you can get it to cure. Norland wants some $1,700 for their curing gun. But here's how you can do it for under $50.Now, I've tried more than one dental curing rig that I've found on ebay. However, it would seem that the wavelength of these types of devices is just too long to activate the curing process in the glue.A quick solution is to goto the hardware store and buy a UV "Party Bulb". It works, but only marginally -- it might take 5 mins to set a single joint that's a few mm's away from the bulb's surface.I wanted a better solution to this problem and a way to apply the UV light to a single point. So this is how I did it...I bought a 5w battery powered dental curing light (http://www.ebay.com/itm/131169069299) and modified it by replacing its long 480nm LED with a 3w 365nm style (http://www.ebay.com/itm/321180753500).I don't have any pictures of the process. But I can say its a fairly easy modification to perform. The only trick is you need to remove the membrane that holds the 'on/off' and 'function' buttons first. Its only held on by adhesive, so just get under one corner with a razor and pull it off. The rest is self explanatory.A few test blobs of glue cured within 10s using this device,. So I'm super happy with it.

author: London Lad
author_rank: Regular Contributor
timestamp: May 22, 2014, 02:15:50 pm
content: Don't forget to use eye protection

author: DmitryL
author_rank: Regular Contributor
timestamp: May 22, 2014, 02:22:19 pm
content: I just bought a 3WT "UV LED" from DX; (don't remember the wavelenght) attached it to a simple LM317 current source.Works as a charm for me

author: CaptnYellowShirt
author_rank: Frequent Contributor
timestamp: May 22, 2014, 02:34:17 pm
content: Quote from: London Lad on May 22, 2014, 02:15:50 pmNo joke. The 365nm LED doesn't even look like its 'on' when its under power. Which of course is the worst kind of 'on' for anything that could damage your eye.

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 22, 2014, 08:32:36 pm
content: What was the point of buying the dental light anyways? Wouldn't a flashlight work just as well and be much cheaper?Many years ago (before UV LEDs were affordable), I had to trace a leak in a HVAC system using UV dye. I just got a blacklight CFL and installed it in an automotive service lamp.

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: May 22, 2014, 08:47:45 pm
content: What about UV devices for nail polish hardening? They available anywhere in abundance. Some use 3-5 hi power UV LEDs some 3-4 CFL lamps. Cost from $20 to $80 or so.Here is LED-based one:http://www.ebay.com/itm/Black-36W-Manicure-Dual-Purpose-LED-UV-Lamp-Nail-Dryer-Light-Gel-Polish-Cure-/161311578470?pt=US_Nail_Care&hash=item258eeb5966

author: CaptnYellowShirt
author_rank: Frequent Contributor
timestamp: May 22, 2014, 09:56:00 pm
content: Couldn't tell you about the flash light or nail thingy. But it would seem the wavelength of the things I've tried that have claimed to be for 'UV curing glue' didn't work with the optical glue.So the real question might be: why not just use the LED? Which you could easily do, but I like the hand-held package and lack of wires running to the device.

author: jeremy
author_rank: Super Contributor
timestamp: May 22, 2014, 10:06:14 pm
content: How old is your glue? This looks like a fairly cheap and effective method for using optically cured glue, but according to edmund optics Norland 61 has a shelf life of 4 months. I presume that is just for the military spec?

author: FrankenPC
author_rank: Unknown
timestamp: May 22, 2014, 10:21:56 pm
content: I wonder if a 405nm laser diode would be near enough in the UV spectrum to cure this kind of glue. Using a lens to fan out the beam of course.

author: ejeffrey
author_rank: Super Contributor
timestamp: May 22, 2014, 10:45:04 pm
content: You should try to rig up a 'tanning bed' style UV cure lamp, too. 15 seconds with the gun will tack something in place, but the joint will continue to harden with up to 10 minutes of exposure. The bed is also safer to use, just put an interlock switch on the lid so the lamp won't turn on until the lid is shut.Speaking of safety -- on the dental curing rig, consider putting a blue/violet LED (possibly even the original LED if the power dissipation isn't too much) next to the UV LED. That well provide a visual indicator that it is on.

author: lanshaoe66
author_rank: Newbie
timestamp: December 07, 2015, 08:54:44 am
content: I always bought a 5w battery powered dental curing light fromhttp://www.dentaltools.fr/category-6-b0-lampe-%C3%A0-polym%C3%A9riser-dentaire.html

author: RobertBG
author_rank: Regular Contributor
timestamp: December 08, 2015, 03:11:59 pm
content: Quote from: CaptnYellowShirt on May 22, 2014, 02:34:17 pmI use a lot of UV activated resins and I always wire up a little indicator to let me know that my UV lights are on.While in there I add a safety switch because my daughter loves flashlights and spending time in the shop with me.It truly is cheap insuranceOn a side I got a bunch of magnetic switches from Banggood really cheap that I use around the shop and house.My wife and I keep a little neo magnet wand on our keys that we use to activate them and it's really convenient for keeping things locked up and out of reach from the little ones.

author: Marco
author_rank: Super Contributor
timestamp: December 08, 2015, 04:10:56 pm
content: If you want even more safety put a visible led in series with it and next to it. 3 Watts of visible wavelength will trigger your blink reflex (with an appropriate color with safety goggles you won't notice it).

author: jeremy
author_rank: Super Contributor
timestamp: December 09, 2015, 05:48:06 am
content: I recently found myself needing to use a bunch of UV glue. I ended up buying the glue (various Norland products) through edmund optics, as well as picking up someUV protective glasses, make sure you purchase ones which have actually been characterised; I wouldn't trust the random ones off various chinese supplier websites. I purchasedthiswhich is basically a $130 365nm nichia LED in an aluminium tube as the UV source. I also ended up buying a second hand UV curing unit off ebay for curing thick stuff quickly, but the penlight works remarkably well if you keep the batteries charged and keep the adhesive thin. Although I'm not sure if they still use nichia LEDs.The second hand UV cure unit has the same sort of LEDs, but multiple LEDs, higher current drive, more heatsinking and 405nm by the looks of it. Cures blobs of glue at a frightening speed.FWIW, I compared my penlight to the$2000 thorlabs UV curing toolwhich I have access to, and I'm pretty sure it uses the exact same LED as the penlight. So if you don't need all the funny timers and stuff, save yourself $1870 and buy an LED