fiberglass or kevlar, and why?

Selling the 'cuda has left an empty place in my heart. :frowning: I’m having a recurring fantasy about a QCC kayak. Let’s say, hypothetically, I did order one. Glass or kevlar? And why?

I know there have been other threads about this but I was having trouble finding them using the search function. So, I apologize if this is redundant.

It’s worth asking, because I gather that
QCCs use of Kevlar may be a little different than more traditional practice.

Kevlar is usually used for inside layers, to take advantage of its resistance to tearing, and thus keep a break from propagating. Most builders of “Kevlar” boats used E-glass or S-glass for the outside. Kevlar usually isn’t used for outside layers, because it has less compression strength than glass, and because it fuzzes when worn, rather than wearing smooth like glass.

A purely glass boat, or a glass-carbon boat, can be wonderfully stiff and quite sturdy enough for touring/sea kayak purposes. And such a boat can be about as light as a reasonably stiff “Kevlar” boat. It is mainly whitewater boats that have benefited from Kevlar layers on the inside, because of the types of blows regularly encountered.

Others will be along who can give you details about QCC “Kevlar” layup, and the kind of boat that results. My opinion is that you’d be pretty happy with one of their non-Kevlar layups, even if it happens to be a few pounds heavier.

ABS thermoformed plastic
and you know why

I agree with that g2d

LOL, yes I know why
What I don’t understand is why all manufacturers haven’t gone that route. Not saying they should; it’s an honest question.

Some of the engineers I work with tell me fiberglass kayaks are a thing of the past - very old tech - and that thermoformed kayaks will displace them completely before long.

Do you think that’s a valid statement? I mean, why do people still make fiberglass (and kevlar) if they’re so “old tech”. There must be a good reason…

In the past, I had always thought I’d go with kevlar if I ever got a QCC, but then I read a thread not too long ago (can’t find it now) that made me re-think that. I recall making a mental note that fiberglass had some advantages, but just couldn’t remember what the reasoning was. Thanks for the info.

Wow, not even going here
other than to say that there are vast differences between composite construction and a capped ABS thermoform construction. Ask Boeing why we are not making ABS air skins…? Unbelievable.

The main reason that glass, carbon and kevlar have not be replaced by thermoformed plastics has to to with tooling costs.

The tooling needed for a hand lay-up construction is very simple to make, and a shop that has the ability to make hand lay-up boats also has the ability to make their own molds.

The mold for a thermoformed thing the size of a kayak needs to be much stronger than a hand lay-up mold, and a “fiberglass” shop would typically not have the equipment to make one. Therefore the molds would need to be out-sourced, at significant expense.

There is also a big investment in equipment required to process the plastic.

Vast differences
Well, there are vast differences between the functional requirements for an aircraft structure and a kayak.


But still the same in more ways than not
Not saying never but there is a huge advantageous difference between fiber (any kine)reinforced / resin matrix parts and popped out, istotropic parts. Its gonna be while still before the latter catches up to the high performance capabilities of the former …

So the former will NOT be the former replaced the thermo form-er anytime soo.

What are
E-glass and S-glass? Not familiar with those terms.

Prijon used to make a glass seayak…

…I think they still do.

Didn’t mean to upset anyone
It was an honest question. I think one guy was under the impression that (for example) Eddyline’s “Carbonlite” is actually made of carbon or part-carbon, and as far as I know, it has nothing to do with carbon. Right? (These are not kayakers I’m talking to at work.)

Mintjulep … you are right on the
last three but I do not agree with your initial statement in its all encompassing capacity.

Money, yes but even the transportation industry giants who can use any process they want still use a mix of soft and hard tooling WITH reinforcements.

The little guys would love to have metal molds but I bet if you handed one to them ( thermoformably ready) many of them would just use the same process they do right now ( hand, vac, infuse ), just with less mold maintenance.

I remember thinking Prijon’s
Eski looked nice. I like the low profiles (no upswept bows, etc.)

I don’t know if they still make anything glass or not. Do you have a current catalog?

Aha! So this explains
why some thermoformed kayaks are so expensive.

I know I’m going off topic here, but while we’re at it…

Why are Eddyline’s t/f kayaks so much more expensive than Hurricane’s? Don’t get me wrong, I love the Eddyline designs (and maybe that’s the answer) but just wondered if anyone else had some insight into this.

It’s my understanding that the first Carbonlite was Polycarbonate. They then changed to a proprietary multi-layer plastic and just kept the “Carbonlite” name. Might have had something to do with polycarbonate being brittle at very cold/freezing temperatures.

S-glass is a version of a stronger FG
developed for the military. It is harder, somewhat stiffer, and somewhat more impact resistant than the more generally available, and cheaper, E-glass. For many applications, it probably isn’t worth the extra cost to use S-glass. It is another cloth that tends to show up in composite whitewater boats.

I don’t think that anyone could make a
20 pound slalom boat out of thermoformed plastic that would approach an S-glass/carbon boat in stiffness. (I have one of the latter.) Impact resistance is another matter, but some Kevlar can help that.

It is interesting that the canoe innovators at Esquif went to a Twintex composite when they wanted a lighter boat that could take punishment like ABS. They were entirely capable of doing thermoformed stuff, but they thought that some fiber reinforcement was needed.