UV curing with LED array doesn't seem to do anything

My UV curing setup consists of a small rotating display table with two Keedox 20W Fast Curing UV Light Ultraviolet Lamps in very close proximity to the workpiece and a mirror to reflect light back into the workpiece. Leaving the workpiece in there for 24 hours or more doesn’t reduce stickiness noticeably. But exposing the workpiece to direct sunlight for say one hour does reduce stickiness noticeably. The sun usually isn’t an option for my workflow; I need to cure at night. I see all the posts about people curing with ~400nm wavelength LEDs. Is anyone else not getting results with LEDs? I use all sorts of resins with the same result. To quote Mugatu from Zoolander: “Doesn’t anyone notice this? I feel like I’m taking crazy pills!”

The LED array you’ve linked emits light at 380 nm.
Formlabs resin cures at 405 nm.

Can’t be sure, but i’d hazard a guess that’s the likely reason you’re not seeing any results.

I got a 25EUR gel nail polish curer, with 12W of 405nm LEDs. I tested it with a drop of resin on a matchstick and it cured it in about 1 second. maybe you can do the same test with yours?
Generally the wavelength isn’t that specific, so I’d be surprised if 25nm made any difference.

If you are trying to remove the sticky surface feel, then washing with warm water is better in my experience. The stickiness left after the IPA washes isn’t all curable, some is just a residue of what didn’t dissolve in IPA, but it does dissolve in water.


Thank you both. I will give one of the nail polish curers a try.

Before you do, try removing the protective glass from the LED array.
Maybe, just maybe, they were daft and installed a glass panel that doesn’t do a good job of transmitting UV light.

I think : The real problem may be box,becuase I also use this method(load ultraviolet led strip http://www.ledlightmake.com/infrared-ultraviolet-led-strip-c-80_92/ultraviolet-led-strip-high-density-420nm-uv-led-strips-p-322.html) to test my products. it’s ok!:smile:

I tried a different UV LED, this one with a specified wavelength of 400nm. It works great. Not sure if the original problem was due to the emitter being not the specified wavelength or what, but the difference was night and day.