So, the same happened.

A year ago I started a thread concerning CTS Crystalcoat yellowing on my rod. Linked pics don't work now, but the rod is a CTS custom white blank, with Fuji NOCP wrap. You could imagine, white blank and white wrap, any hints of yellow would be obvious but CTS claimed their stuffs do not yellow, and some members, reviews, agreed about that as well, so I am curious.

Have they tried on white blank, white wraps, like me? Or on other colors so that hint of yellow could not be seen?

[www.rodbuilding.org]

So a year later, the same happened again.

Below is another rod I finished in late 2020. White blank, ghost wrap this time (clear silk). The wraps finished very nicely at first they were very transparent, almost disappeared.

After a year and half. They turned yellow, again. And no, not sunlight. Due to covid I have only fished this rod for 2 or 3 times. Then, stored inside the rod cabinet for a whole year. I just took ot out to see and it turned yellow.

The yellowing this time is more even, compared to the other rod I asked about a year. Only on a few guides, the epoxy edges show darker yellow.

Nothing too terrible, and I'm not blaming CTS. I am just curious to know, do all epoxy turn yellow ? If it is unavoidable, I would avoid doing such white or clear wrap on white blank in the future.

Cheers.

Yep, all do. There are other finishes that don't, but are longer, or more difficult to apply in a production environment

All epoxies will tend to yellow or amber over time, whether in the bottle or on the rod.

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Alex,
Unfortunately, due to their chemical make-up, all epoxies will yellow; some faster or slower, some more so than others; the overwhelming amount of the yellowing is due to the hardener but the resin plays its role as well. The environmental factors that cause the yellowing are oxidation, moisture (to a small extent), and UV. Even if isolated from UV, the hardener will yellow in the bottle due to oxidation; the only way to slow the yellowing down is to purge the bottle with nitrogen but that is obviously impractical. After the resin and hardener are mixed and cured, oxidation only occurs on the very surface of the epoxy as the underlying material is sealed-off. However, UV penetrates all the way through the “clear” cured epoxy, hence the entire thickness of the epoxy is exposed to the UV and susceptible to yellowing. Although a hardener may have yellowed or even turned purplish-brown, its properties have been compromised virtually nil. Nonetheless, no one wants to use an epoxy which is already darkened.
Through my unscientific tests and experiences of a half dozen different thread finish epoxies, I have found CTS Crystal Coat to yellow the LEAST, with Flex Coat and Thread Master closely following. The worst I have found is Pro Coat.
When looking at most thread wraps through a thin layer of epoxy, the yellowing is barely, if at all, noticeable. But with lighter colors, not to mention your white-on-white, the yellowing becomes much more obvious.
Although I have not tested it for yellowing, some claim that U40 Perma Gloss remains crystal clear and does not yellow. I have been pleased with PG’s performance in other respects and suggest you consider seeing if it “suits your fancy”. Otherwise, go with black-on-black lol.

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

PermaGloss is a moisture curing urethane. It will not yellow. This is a fact rather than a claim. However, it is a very thin product and will require many coats to achieve much in the way of depth. It also has a different look than epoxy. Some like it while others prefer the look of epoxy.

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I saw a test done on different rod wrapping epoxy brands where they were exposed to sunlight and pictures were taken after a month. The one that came in second to the last with the least yellowing was Gen 4. Doc Ski did the test but he did not include all of the brands mentioned. Here is a link if you have FB.

[www.facebook.com]

You need to remember that we use a particular resin for different reasons and they may not all be about perfect clarity. How much does it bubble, how well does it mix, what the acceptable set and cure time will be, how flexible will it be, what the finish appearance is, etc; will be the basis for your use, and I can promise you this, you will have to compromise somewhere.



Edited 1 time(s). Last edit at 04/26/2022 07:14PM by Lance Schreckenbach.

The trouble with so many of the epoxy "tests" is that you don't know if the epoxies are all the same age at the outset. They might have been applied to the test media at the same time, but if one kit was 6 months old an another 2 months old, then the test results taken after a month's UV exposure will almost surely favor the "younger" finish.

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As I stated, Tom, my “tests and experience” was “unscientific”. You are correct that one has no idea how “fresh” an epoxy kit may be; and it certainly would have an impact on the results. My samples were purchased through the site sponsors to the left which should provide the most “consistent variable” for all of us here. The existing samples of CTS Crystal Coat, Flex Coat and Thread Master have yellowed to some degree (minimally / acceptably) since purchased ~ 1 year ago, but the Pro Kote is almost black and has gotten darker within that same amount of time!!! By the way, the Pro Kote has never been opened.

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

I was responding to another post but your points are well taken.

And yes, these products (hardener) will yellow or amber in the bottle even prior to being applied to the rod.

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Does epoxy lose strength over time - or only its clarity?

It certainly degrades and this is what most UV inhibitors are intended to reduce or slow (not the yellowing). But the issue of strength degradation in terms of what we use epoxy wrap finish for isn't much of an issue, at least not for many, many years.

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I havent tried this on thread wrap yet...
But I have been using a UV resin and absolutely love this stuff.

Its just a one part resin that is activated with a UV torch.(or just UV light)
The light needs to be in the realm of 365nm.

Whats pretty cool is the setup is almost instant.
A lot of lure makers use it for a final coat on hard baits.

I know that this will not yellow...Im just not really comfortable with it as a replacement for epoxy.

Tom Kirkman Wrote:
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> It certainly degrades and this is what most UV
> inhibitors are intended to reduce or slow (not the
> yellowing). But the issue of strength degradation
> in terms of what we use epoxy wrap finish for
> isn't much of an issue, at least not for many,
> many years.
>
> ..........

Just adding...
The UV inhibiters are short term...mostly about a year.
One thing people tend to overlook it that the UV inhibiter is ONLY for the epoxy.
It does not BLOCK the UV light.
By this I mean that it does not block UV light from effecting whats under the epoxy.
You see this happen with hardwood floors and walls.
With inks (4 color process) UV will typically zap the yellow out...making a green go blue.
I also effects thread...though differently than ink.

Yellowing epoxy is real, but I now work with it and have zero concern regarding it. To start, I use Gen4 which is low yellowing. Next, I choose colors less impacted by yellowing. Purples and maroons are straight across from yellow on the color wheel. They help cancel any slight yellow overlay. Blue isn’t far away, but far enough from being straight across on the color wheel that it obviously turns green under a yellow overlay. Maroon is a very classic thread color that looks good on raw graphite and many other colors of blanks. I’ve started tinting the epoxy with VooDoo Dust that closely matches the thread color I choose, which is more and more becoming maroon. It makes for a rich look and the thread is still visible. I will be very surprised if yellowing is ever evident decades into the future with this process. If I liked white blanks and thread work I would be more stuck, but white dust pigments might help.

Rod builders are divided into two camps: Those who seek form and those who pursue function. The two are often not compatible. The blank coated with paint, layers of clear finish, and decorative rod wrappings are attractive works of art but they produce a slower and less sensitive rod, while the bare blank with the fewest rod wrappings and least amount of finish finish aren't very pretty but are lighter and more sensitive. It doesn't make much sense to judge these two different styles of rod builds with the same criteria . . .?

It's almost scary how much sensitivity is improved just by using braided line..even on glass rods.

I have unopened bottles of Thread Master, Flex Coat, and Dura Gloss LS, all of which are probably 10+ years old, or whenever Thread Master first came out. The Flex Coat hardener is amber, the Dura Gloss hardener is dark amber, and the Thread Master hardener is brown. All of them have been kept in a drawer. I have bottles of all three that are almost empty, and they are the same color. It is kind of odd to use any of them on a new build, but if I stick to dark blanks and wraps I figure it doesn’t really matter. Nature of the beast, I ‘spose.

I have just completed a build on a CTS arctic white 13' float rod blank with white NCP wrap. I used Permagloss on the wraps, no yellowing thus far, and since it's a urethane I don't expect to see any yellowing over time. However, I'll report back if I see yellowing over time.
As Tom mentioned, the Permagloss is a very thin product. I did 3 coats, you don't get the nice high gloss shine that you get from epoxy but I just needed the no yellowing, durability and slight reduction in weight that PG provides. Function over form for me but I do like the minimilistic white on white over the 13' length of the blank. Hopefully it'll stay that way! I am by no means an experienced builder but have been carefully following the threads on this board for my choice of wrap for this build. My only remaining concern is will the thread itself yellow over time?
To reply to Alex; as many have already mentioned I think any epoxy will yellow over time you'll need a urethane for white wrap on white blanks.

Rob Cain Wrote:
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> My only remaining concern is will the thread itself yellow over time?

UV typically will not yellow the thread...only fade it.