Uv Cure

[eagleflyfisher]

Little help please, using loon uv finish, really thick stuff.

Coated fly head & hit it with uv lite. New batteries yes (4aaa) nice and bright.

Still remains quite tacky.

Does how thick it goes on matter.

Are there different uv levels that are only suitable for some products?

Be nice if the sun was shining today, that sure cures well.

 

Thanks.

[murray]

Dave, I've used Clear Cure Goo for several years now, sometimes applying it quite heavy. When I hit it with the light, it hardens up fairly fast. No more than 10 or 20 seconds for it to feel dry to the touch. I have heard that there are two different types of UV lights. Is it possible that the Loon product uses a different light?

[BrianR]

I use the thin stuff.If I want to build it up,i have a foundation.Are you using a Loon Lite? How long are you hitting it with the lite.

[eagleflyfisher]

I use the thin stuff.If I want to build it up,i have a foundation.Are you using a Loon Lite? How long are you hitting it with the lite.

 

 

I think my lit is called a power light? Quite heavy , short lots of holes in the end where the light comes out (blue)

Minutes & minutes and still gummy. I even tried a couple of different uv lights out of my kids reptile tank.

I know the product cures, I used the sun a few months back when I bought it.

[CDone]

Is it gummy soft or just 'tacky' feeling? wipe the head of the fly with an alcohol wipe after hitting it with the light, should remove any of the tacky feeling. I use the CCG Hydro, thin like water, two coats builds a nice head. No Tackiness at all.

 

Colin

[DonAndersen]

Eagle...

 

Loon UV stuff is meant to be flexible whereas some of the other products are not at all.

I bought UV for just trait.

 

Don

[eagleflyfisher]

Ok thanks guys, I'll give it a wipe Colin & thanks don thought it would dry harder

[BigFoamy]

Loon stays a bit tacky, I dont like it for that reason. As soon as you touch it it leave and imprint of you're finger print on the head of the fly. To combat this I add head cement after to get that hard, shiny, slick feel to it. I wont buy it again once I'm out.

[SilverDoctor]

there two things I can recommend, one is to hit it with a quick coat of Sally's the other is to leave it in the sun for a few days. The latter has work occasionally the former always.

[Ricinus]

What Lornce (Silver Doctor) said..

 

Mike

[eagleflyfisher]

So I tried my light, my daughters gel nail uv drying aparati & stayed tacky.

Sunny today so brought flies into the sun and hit it with my magnifying glass.

All dried pretty darn hard with a good gloss to them.

I was building up pretty thick heads on these one so maybe too much for the uv flashlight.

I hope this stuff is tough , I've got about 8 bucks in polar bear tied into each one!

[Myth1228]

Another thing some friends of mine do is to put a very, very light coat of Loon UV Flow over top of things they build up using the Thick because the Flow dries without tackiness.

[monger]

Your flashlights to do not have all wavelengths of light to harden everything up....put the sun does.

The resins you use have specific wavelength requirements...so you need to have the right flashlight.

I believe these resins come from the dental industry. Just ask your dentist if he wants to donate his light next time

[RedBeard]

Hey guys, I was having this issue too, and the tacky finish on my flies was collecting dust & dirt and making my UV wingcases and heads appear dusty and not clear.. I emailed Loon and this is the response I got.

 

Murray those flies you tied me way back did have a really nice UV epoxy shell on them. I may have to try the UV clear cure as well!

 

Hey Steve,

There is a short answer to your question and a long answer. I'll start with the short answer in case you're not interested in the long one!

The short answer: all UV resins are subject to remaining a little tacky due to the way that the resins interact with oxygen in the air. It's not an issue of light, amount of time exposed, or anything that you're doing... it's that darn oxygen. The quick fix is to cure your resins and then wipe them down with an alcohol swab. This will remove the uncured resin from the top of the applied resin and you'll have a tack-free fly.

The long answer....

The science:

The tack that you're experiencing is the result of "oxygen inhibition", which is a fancy way of saying that oxygen inhibits the outermost layer of applications of UV-curing resins to fully set up. In other words, the application should be cured all the way through, save that outermost layer that still feels tacky. If you picture a cross section of the resin, then imagine it curing from the inside out. The outermost layer, which is exposed to the ambient air, may remain tacky even though the rest of the applied resin is fully cured.

The variables:

Overcoming the effects of oxygen inhibition and producing a tack-free surface cure is dependent upon several factors, including:

• Heat generated by the UV curing system
• Intensity generated over the entire UV spectrum (200-420 nm)
• Exposure time

The benefit:

The tacky exterior provides a more suitable surface for bonding between subsequent layers.

I hope that help Steve. Thanks for the email!

Brett

[eagleflyfisher]

Thanks for your efforts Redbeard, will try that method.

I did just use the sun & it dried them quite well, just a little tack left on them, enough to still leave fingerprints though.

 

[murray]

Thanks for the post Steve. Good info to have. I'm finding that the Clear Cure Goo is a bit tacky now with the batteries on my light getting weaker. Sunlight cures it to a hard Finnish though. A word of caution though. If you are using you UV resin outside on a sunny day, you might find that it starts to set up in the dispenser tube.

 

Murray

 

[RedBeard]

In the dispenser! not good!

 

Much like me, my UV cure never sees sunlight lol