UV Curing Problem

[Flatshad]

I finally decided to build a UV curing box and have a question for you gurus. I built what I consider a really nice box lined with all plastic mirrors and 2 40 watt LED  UV lights in the top. I would have been as well off with one but for $38.00 I figured I’d just go ahead and put 2 in it. Anyway I decided to try it out today. First let me say that Alumi UV is on back order so I got some Chinese stuff off Amazon to try it out. I painted & coated about 25 spinnerbait’s for my test. The UV coating was as hard as a rock in about 15 minutes on every spinnerbait but they are tacky to the feel. Have any of you guys run into this? And will the Alumi UV take care of this. I’m gonna put them out in the sun tomorrow and see what happens. Any ideas would be appreciated. Thx

[Travis]

Likely oxygen inhibition.   Some products are worse than others due to formulation.  Different formulations cure better at slightly different wavelengths.  

Often if there is just a tacky surface but the bulk has cured you can just wipe it clean with isopropyl alcohol.

Edited January 21, 2021 by Travis

[Fishermanbt]

I too have been using the Chinese uv resin. I have not ran into any tacky issues with it. To me it sounds like it just needs more time in the chamber.  Check to make sure the lights you are using are the right wavelength for the resin. 

My question is how are you applying the uv resin?  Dipping, brushing on one thick coat or are you brushing on multiple thinner coats between drying?  

if you are having trouble laying down a thin coat I would suggest the following.  Get some warm water from the sink in a container and then place the uv resin bottle in the water. The heat will thin it down greatly and it applies much easier. 

[Fishermanbt]

From what I read on the Let’s Resin website they suggest if there is tackiness to put the project out in the sunlight to get a full cure. 

[Vodkaman]

Mirrors are a good thing, they do help with light distribution. BUT, it is not just about lighting up the lure, it is all about the distance the light travels, it is about the light strength.

If the distance doubles you might think that the strength halves. You would be wrong. The strength reduces to 1/8th. Over-reliance on mirrors could be the problem, something to consider.

Dave

[BobP]

It takes about 30 minutes inside a nail uv cure box to harden the Chinese resin I have. Different resins are designed to be hardened at different UV wavelengths and a given lamp may or may not work well on certain resins, but most will eventually get the job done. I’d give it an alcohol wipe like Travis recommends after giving it more time under the light.  I don’t think you’ll have this problem with Alumi-UV, but the Chinese resin is much less expensive.

and yes, curing resin in sunlight is a good way to go since the sun puts out a wide range of UV.

Edited January 21, 2021 by BobP

[Flatshad]

A small update. It was cloudy and rainy today so I left the baits in the curing box all day from about 8 this morning till just now (9 pm) and they do feel some better. It’s suppose to be sunny and in the low 50’s tomorrow so I’ll put them in the sun tomorrow and see what the outcome is. Hopefully the Alumi UV will fix the problem as this isn’t gonna save me any time the way it is. Thx again for all the reply’s.

[JSilva]

Is there a temperature range for curing in sunlight?

I've got the slightly tacky issue that others have mentioned (Let's Resin product) after curing under my poor excuse for a Nail light that only has time options for 30,60 secs at a time. (anyone got an electronic hack to disable the timer? lol

We're at freezing temps here in New England so I'd assume outside is a no go. Couple of days on the windowsill help you think?