fiberglass or kevlar, and why?

Same Delimna

– Last Updated: Jun-04-08 5:23 PM EST –

I went through the same thought process when I bought mine. How much difference could there be in 8 pounds if it is spread over the entire length of the boat? Is it the difference of a gallon of water placed in the cockpit? Or the difference of me weighing 180 or 190? I was told not really.

I was told (not by QCC) the diffence you will notice is in the livelyness of the boat when it is moved side to side and up and down. The way it was explained to me was to imagine a one pound weight on the end of a 9 foot pole. Now swing the pole side to side. Now imagine an 18 foot pole with one pound weights on each end. Stand in the middle and move the pole around. It will take much more effort to do this with the weight than without the weight. Swing weight is important whether choosing a paddle, boat, bike tire or any other item that rotates around an axes.

So I ended up getting the carbon/kevlar. I don't really know if it is worth it but I like the boat, I could afford the difference and I don't have the lingering question of whether I should have spent the money every time I paddle it.

I love the boat (700) and will likely get my wife a 600 within the year. We will likely get carbon/kevlar again.

Good luck.

I think so. I may have gotten…






…rid of it because it was sitting around because I

was slobbering all over it.



get my email?


Kevlar
the QCC kevlar boats are good and stiff, yet lighter than fiberglass.



Cheers,

JackL

All encompassing…
Sorry, add “in the small boat manufacturing industry.”



Was not my intent to apply the statement to every possibly use of fiber/resin composite.

'Cause You Can…
…fix 'em!!!



Are your engineer friends paddlers? Do they maintain their own kayaks? Have they ever tried to fix any significant damage to a plastic hull? If “No” to the above,smile politely at them, and ignore their opinions on this matter…

But are they all Kevlar? No, and to
appreciate the result, you have to know what else is in there to help make it stiff.

tough to repair

glass
1. it’s cheaper

2. does a few pounds difference really matter in your particular application compared to getting a smaller boat or a boat that is designed for light weight to begin with?



I got a QCC400 as a spare kayak. In glass without a rudder. It’s as light or lighter than the average kevlar kayak with rudder.



I like glass because in the long run you’ll probably have fewer soft spots in heavy use.





If a person wanted light,the boat should be designed with light weight in mind, not just exchanging one fabric for another. There’s a few painted composite Manitou 13,14 out there in glass. That’s what manufacturers should do it they want to sell you light,

Agree there too Lee

My '97 FG Caspian Sea / 400X is 11 lbs
heavier without skeg or rudder than my 2007 kevlar QCC 400X with rudder. The newer FG 400Xs are several lbs lighter than my 1997 model. The 1997 Caspian Sea /400X is much stiffer than my 2007 400X.


soft spots?
re: “…have fewer soft spots in heavy use”



What does that mean, soft spots?

Some have reported that “Kevlar” boats
develop “soft spots” with heavy use. Delamination? Mysterious water creep through Kevlar? Salty may want to share his observations. On composite whitewater boats, a couple of layers of S-glass outside, and a couple of layers of Kevlar inside, with reinforcement in places, is a fairly common formula. I own such a boat, which I bought used. It was given a pretty good pounding on the Ocoee, Chattooga 4, etc., by a paddler more aggressive and more skilled than me. The boat had a few minor checks/cracks in the surface layer of S-glass, which I easily repaired in a couple of hours. Looking around inside, there was no “softening” and it appeared that no significant delamination had occurred.



If a glass-over-Kevlar boat is hammered and pushed in often enough, then what is likely to result is munchy glass on the outside, with stretchy Kevlar kind of holding things together inside. This may reflect, not any inferiority of Kevlar, but that it has done its job. An all glass boat is just going to crack and munch under severe stress, and the cracking may propagate more because there is no Kevlar there to limit propagation. Weight for weight, a properly laid up glass/Kevlar boat should be somewhat (but not wildly) tougher than an all glass boat.



There are other stretchy fabrics sometimes used to limit propagation of cracks. Polyester is one. Nylon is another. Neither has the same degree of toughness as Kevlar, but when polyester is laid up with vinylester resin, the resin to fabric bond is better than it is with vinylester and epoxy.

We had a
thermo plastic boat (CD kestrel 140 TCS) repaired following the advice found on this forum over a year ago. It fell off a moving trailer and was dragged a ways…

We were, and still are, very pleased with the results.

The TCS seems to hold up well sliding over logs, scraping over limestone ledges, and the occasional oyster rocks.

I would recommend it.

T

That settles it
My fantasy QCC is going to be fiberglass. I may add an imaginary rudder and thigh braces, too. I think I can skip the compass since I’ll be fantasy paddling it in familiar places. Color will be Canada Red with black trim and white hull.



Thanks to all for the education. It may come in handy someday when/if I can ever afford a real QCC. (The fantasy ones are so much less expensive, plus I can change colors anytime I like!)

Donna, remember that the “answer” may
be different for different brands, and for different boat models. There are no safe generalizations about use of Kevlar, or carbon, or cupholders in boats. Every instance is, in some ways, unique.

Could read …
“Every high performance product not driven by profit.” as well.


Who cares ?
She asked the question I answered the question.



I have wood thwarts and aluminum thwarts in several of my kevlar canoes. I am quite sure the canoes are still light weight because they are kevlar.



Cheers,

JackL

Hey Donna…
You need to send some of these so called “experts” over to my place and let them point you out the soft spots ( NOT ) on either my QCC-700, or the 600 or the 10-x.

You get what you pay for, and you won’t find soft spots, delamination, or any other problems that some of the other kevlar boats have.



That could just be the reason that the QCC’s are guaranteed.



Cheers,

jackL

My thoughts
are that this is an excellent application for a Kevlar glass lay-up. Especially with the quality manufacturing of QCC. Boats like these represent a use profile that makes sense for such a lay-up.



If you can afford it, the weight savings will be appreciated long term.

Donna,
A better source for understanding these different materials would be a supplier of said materials, or a composite engineer in Aerospace or Yacht manufacturing. Representatives from the suppliers usually are very knowledgeable and you’ll get far better information, and “reality” rather than marketing reinforced emotion. Direct talk with the builders of some of the better kayaks will also be very productive.



Materials are just materials, each with it’s pros and cons. Applying the right materials in the right manufacturing process to a desired objective is the key. There are few absolutes.