well my personal
observation is that kevlar was best on the outside when I smacked the inside corner of a concrete pool edge when doing a fast roll. ~1" of gel cost chiped off and the kevlar was exposed with not even a scratch on the epoxy coat or fractures in the kevlar cloth. I think carbon would of likely shown some fracture lines under the same conditions. That is based on my experience with “fiberglass” surfboards.
just make sure
you use a “water proof” contact cement, not all are.
That only shows how gelcoat chips.
The epoxy paint on my slalom boat chips off the underlying S-glass in a similar way.
The carbon/S-glass out, Kevlar in rule has been derived over decades of collective experience of builders making boats for whitewater. It is true that when a WW boat takes a shot to the hull, the S-glass surface layers may crack a little, but the Kevlar underneath keeps the boat together. If the boat were built the other way around, the same blow would crack the S-glass inward, and possibly tear the overlying Kevlar.
QCC is making boats for different conditions. Maybe there is something about having the carbon inside that pleases them. But they’d go broke laying up whitewater boats that way.
The arguments from internet
experts continues!!! I knew this would happen here.
Well, as I recall, Salty, you would
rather just skip the Kevlar entirely. But if someone has to have it, inside is best.
Epic does it right
They use cored Kevlar for their ultra-light lay-ups for racing. They put a disclaimer on those boats and ask that they be treated carefully.
In a race application, or any application where weight is critical, Kevlar makes sense.
Note their standard lay-up is Carbon, Core, Glass with a light gel coat. This is a more durable long term lay-up.
I’m with you on the kevlar making more sense on the inside.
You are correct that I would prefer it not be used on a boat spec’d for me, and definitely not in a surf kayak for me.
Over and over I have said that fine boats can / are made with Kevlar. It would not be my choice.
I can take a hammer to my carbon / glass, infused, cored hull and repeatedly whack it with no damage.
I think QCC does a fine job of building kayaks!
My “Kevlar” QCC is Kevlar in/glass out
So they obviously know how to take advantage of the different material properties.
I suspect they are not doing Kevlar out/Carbon in for reasons already mentioned here. The inner carbon is likely EXTRA carbon for added stiffness in key areas (cockpit/bulkheads) and for aesthetics (so folks see some of what they paid for).
Oooooo Carbon…
“for aesthetics (so folks see some of what they paid for)”.
That’s probably the smartest reason I have heard yet. I remember years ago I bought a sailboard with carbon. They left a one inch circle unfinished so you could see the carbon. Mountain bikes do the same thing. If they do paint the carbon bike frames they usually leave a small area natural. Oooo Carbon… That must be fast!
I ordered a QCC 700 Carbon/Kevlar. Not sure why except someone said it was better. Hopefully it will be. At least it will look fast from the inside if not from the outside.
Well all I can
– Last Updated: Jun-11-07 10:15 PM EST –
say again is that this kayak took a direct hit on a concrete corner AND all that happened is the gel coat chipped off. I really whipped the bow into the concrete corner during the roll (was just learning). The kevlar on the outside did not crack, the carbon on the inside did not crack. That is the kind of kayak I want, light, strong, and able to take a hit with only the gel coat being chipped.
I did not buy a white water kayak, I bought a sea kayak. g2d, if you want kevlar on the inside because you read it is good for white water kayaks, GO BUY A WHITE WATER KAYAK!! But please do not tell me it is the wrong layup for a sea kayak, especially after saying you would extect some damage to the glass on a hull made the way you think it should be made!!!! Give me a break.
Don’t know all the ins & outs
of kevlar and carbon inside and outside but I have owned a kevlar/carbon QCC 700X for 5 years now and have nothing but good things to say about the layup. It has proven to be a very durable and low maintenance layup. The carbon interior layer is dense and durable, rinses out very easily, and is highly reistant to scuffing or scratching. The kevlar/carbon layup is noticeably lighter and stiffer than the kevlar layup and as mentioned previously plenty durable for the vast majority of sea kayaking applications.
Ah, you’re working from a very narrow
knowledge base, aren’t you? Sad. I suggest you cast around and find out what manufacturers are really doing, and then average that out.
Why don’t you
get some real life experience on the topic in stead of depending on text that you read and is inapproriate? Your posts really expose your lack of knowledge “first hand”. Sounds like you either have a conflict of interest, or are just jealous you do not own a QCC with a carbon/kevlar layup!
As for life experience, I have owned
a number of composite boats, some all glass, some CAP and Kevlar, one glass and carbon, one all CAP, one glass, Nylon, and Kevlar. Most of these have been damaged, and I have had to repair them myself. I have done so based on decades of cumulative knowledge about composite canoe and kayak layup.
The good reputation of QCC kayaks is widely recognized. You note from one of the other QCC owners that their “Kevlar” kayak is glass outside, Kevlar inside. Your boat is somewhat of an anomaly. This does not mean it is a disaster of design, only that QCC used carbon inside the boat when technical considerations and the weight of practical experience would suggest they would put the carbon outside.
You are quite correct that your boat is not a whitewater boat, and the little incident that chipped gelcoat off the boat may be the most significant you will ever incur. But some people do surf kayaks off rocky shores, and those people would benefit from a more conventional layup. Don’t assume that whitewater boats live in one universe and touring/sea kayaks in another.
I own one boat where the carbon is in the “wrong” place. My slalom c-1 is S-glass outside, and carbon inside. I would not have ordered it that way, but I bought it used from a paddler who designed and raced it. If he severely broke a boat, he simply got the Dagger composite team together and made a new boat. Having the carbon inside means the boat is incredibly stiff, and that cut seconds off his times for the '96 Olympics. For some reason, I have never broken or cracked the boat. Note that if it had Kevlar outside rather than S-glass, it would actually be less stiff and more breakable.
So, I never wanted to imply that your boat is a piece of junk, but I have very good reasons for saying that Kevlar is not the best “outside” cloth, while S-glass and (if scuffing is not an issue) carbon are best used as the outside layers when Kevlar is also in use. QCC seems to think so, in some circumstances, but not when they go to carbon.
have you ever built
a kayak?, of course not! So again I point out that you lack real world experience. Repairing is not building. And building thousands of kayak and seeing how they fair in the hands of thousands of people is real word experience.
You are clearly biased on this subject, and I do not know why. But it indicates that you are unprofessional. And that is unfortunate.
Professionally, I am a clinical
psychologist, so don’t expose more of yourself than necessary. I do not see why it is necessary for me to have actually built a boat to comment on boat construction. Do you? I have no more general bias against QCC than I have against Toyota, though I somewhat prefer Hondas. The fact is, you have gotten yourself into a hissy fit from which you now cannot escape.
QCC is a solid composite - Not Cored
Kevlar makes more sense on the inside of a cored structure.
A QCC is solid composite structure without a core. The whole layup is about 1/8" thick. This means the inner layer of composite will deflect nearly the same amount as the outer layer. There will not be a significant difference in the amount of tension a Kevlar fiber is put in whether it is inside or outside.
Kevlar has very poor abrasion resistance. I’ve completely worn through the inner layers of my old Kevlar QCC700. Fortunately all QCCs have a light layer of glass as the outermost layer against the gel coat. This provides great abrasion resistance. Carbon and glass have much better abrasion resistance than Kevlar.
For these reasons it makes more sense to not use Kevlar on the inside exposed surface of a kayak if the kayak is non-cored.
I don’t like Kevlar in kayaks because it is not stiff enough compared to glass or Carbon. However, I think a good application would be the inner layer of a cored surfski.
Still, if given a choice I personally would choose carbon/core/carbon because stiffness is more critical to efficiency than most paddlers realize. Certainly a heavier paddler in rougher water would want the stiffer layup that carbon provides over Kevlar.
love it
I love your first line of that post g2d.
(I’m sitting here reading this waiting for my kevlar kayak to dry so I can actually lift the darn thing…)
Agree with some of your points, but
Kevlar inside on non-cored boats doesn’t seem to be associated with any consistent problems. My used (~6 years) S-glass out/Kevlar in c-1 does not shoe any interior wear, or breaking. One of my kayaks is Kevlar inside, CAP outside, and I will have to watch for indications my heels are wearing through the Kevlar.
stiffness ? will you notice, I doubt it!
I have 2 racing canoes, one kevlar and one carbon, they say kevlar is lighter, carbon stiffer. Forget all the that and enjoy paddling. If you’re not racing (sounds like you’re not) will you notice a differnce, no! Treat your boat with care and leave it out of direct sun and you’ll have years of use out of your boat!
It’s all makin sense now!