Clear coats: what are they exactly and why do they yellow? A tougher answer than you might think. Tune into this #carbonqueries episode for the full answer.
Dan: 00:02 Welcome to the #carbonqueries podcast, the interactive show where we answer your carbon fiber related questions hosted by Ruckus Composites. You can submit a question using the #carbonqueries onfacebook, twitter, linkedin, or email.
Dan: 00:17 For today’s edition of the carbon queries podcast. Our friend Paul also sent us a question through instagram and he asked, why do all of my old frames fade? The epoxy turns yellow over time and the paint underneath takes on a yellow tinge. Why don’t manufacturer’s spray and automotive clear coat over? The epoxy to prevent fading is yellowed epoxy weaker? Oh, that is a great question. Thanks for the submission Paul
Shawn: 00:45 The bike hasn’t been a clear coat already on it. The clear coat is probably just degrading. I mean, all those clear coats are a mystery. In short, there are painted in another country that has many other environmental regulations that mean. Sorry, they don’t have environmental regulations like we do. I mean as many. So it’s hard to know their bikes are really clear coated with there’s not that many tests. Paul, right? Paul, you know, what I’ve always wanted to do, Paul, is they make these, uh, I wonder they call exacerbated test life procedures in environments to test failure modes and something and you think fatigue test, they put it on my machine, that shake, shake, shake, shake. I’ve always wanted to do the UV booth is the thing they use in other industries basically on take sections of clear coats of bikes, put them at a high uv environment and basically you can extrapolate their lifetime on a sample window.
Shawn: 01:38 So basically we would expose him to nonstop UV light for eight days, 24 hours a day. You would then be able to extrapolate based on their exposure, what that could look like two years from that, right? That’s kind of the idea. It would actually have to do the math on it to figure out what that correlation is. And I’ve always wanted to test different manufacturers because we have our own guesses of a lot of manufacturers fade more than others. Some of their clear coats get brittle with time. Same thing when they start taking on sun damage. Those clear coats are typically getting brittle. So then they start cracking more over time as well because they’re losing their flexibility. What you can do and that sometimes the trick is to go a little further on this is the paint underneath itself is not faded. It’s just the clear coat is now like a tinted lens.
Shawn: 02:26 Think of it as like a yellow pair of sunglasses is how what’s going on because the clear coat is totally clear. So it’s a lens right now, a great lens, but it’s lens and it’s a tinted lens. So it depends how far, how deep the UV light has penetrated that clear on. If it’s even touched paint yet. There’s some bikes that we’ve restored where we just have to surface sand the clear coat and then we’ll get that yellowing out of it. Or you can buff it and when you buff something you’re removing a top layer of material and that can remove it. Like if you’ve ever been the headlights on your car, you know they’re all yellow, same idea. They get with time a UV and
Dan: 03:02 Just a point of correction for Paul’s question where it’s not the epoxy yellowing, it’s all the clear coat. But with some I, but it depends on how deeply it goes into the clear coat.
Shawn: 03:11 And most epoxies will definitely yellow at a time and they will weaken with time. It would take a lot of exposure before that really happens to a bike because. And yet again, they’re black and light UV light isn’t going to necessarily penetrate the carbon, you know what I mean? It’s going to penetrate the top layer of epoxy but at that point. It’s gone through a lot of stuff. Um, if it has primer on it or paint, it’s protected your clear coat here, your paint going to get ugly. But the carbon itself is still protected. I really, really, really wanted to do this uv test. You know, it’s like an exposure tests I think is what they call them. You know, who has got a cool booth is a and dial up our friends at freightliner. I’ve done a tour there and they have insane. I mean, tons of companies do this.
Shawn: 03:54 I don’t know if the bike industry does, you know, they need a test these coatings, I mean a semis gotta last. It takes a lot of abuse in the sun, rain, snow, so they have these exposure tanks already for whatever tasks there. Their testing like salt spray and like road grossness um, I’ve also, I’ve always wanted to do that on a galvanic corrosion, like do an exacerbated because we’ve seen some bikes that are less than one year old and are completely degrading very quickly. Yeah. And that’s a whole new issue. But Paul, thanks. I love that question. Actually. Sorry, I went off the rails a little bit. If you need more follow-up has sent us another question. That was a good one. I’m really want to do that test because we have so many bikes. I just wanted to go nuts with the UV light and blast them and see like what looks after day one, day two, day three, who’s going to be the winner. Thanks Paul.
Dan: 04:49 Thanks for tuning in to the #carbonqueries.If you have a pressing carbon fiber related question. You can submit it to us using the #carbonqueries on instagram, facebook, twitter, linkedin, or email. And we’ll talk to you later on this week.