We were kicking around the idea how composite boats crack on roller launches, there is a guy, Eric, who started a company called Apex that is building a Carbon Fibre River Running Whitewater Kayak. I asked him how in the heck can you build a carbon fibre Kayak with enough impact resistance to do river whitewater. He said Carbon Fibre/Impact Resistant Epoxy, Kevlar and Foam Core, that his boats are 1/2 the weight of a Roto-Mold and at that weight they have a little less impact resistance than a RM, but much better performance. If they were built the same weight as a RM, they would be “way” stronger. That was very surprising. He is building the boats for performance…Interesting.
He’s building a foam core carbon/Kevlar boat, not a carbon fiber boat. The best of two worlds. The lightness of carbon fiber and the strength and impact resistance and Kevlar.
Carbon/Kevlar is a common option for many high end sea kayaks.
Yes, but as far as I know this is the first Carbon Fibre river running whitewater kayak available to the public that is not an outrageous price. He refers to them as Carbon Fiber Kayaks, that is the only reason why I used the term, though they really are not. I did not know it at the time, but this guy is Eric Jackson, 3 time World Champion. He said Carbon Boats are common at the Olympic level in Slalom and a lot of Freestyle Kayakers use them but they have been expensive. His is around $3,200. He says they will hold up but you would have to be more careful around rocks than in a Roto-Mold because he makes them so light. I didn’t think river runners would go for that, I thought they would want something indestructible.
Carbon fiber boats and kevlar boats tend to be lighter but that does not mean they are fragile. Now a lot of boats have light hulls but reinforcement in zones of weakness like the chine and gunwales. A kayak designed for fast water can still be strong and made of carbon fiber.
In Eric Jackson’s, the owner of Apex, words, he is making the white water kayaks 1/2 the weight of a Roto-Molded boat for better performance. In his words, at that weight, “you would have to be a little more careful around rocks than in a Roto-Molded boat.” He also said, if he made his Apex white water boats the “same” weight as a Roto-Molded boat, his Apex kayaks would be “way” stronger then a Roto-Molded boat, his words. He is shooting for a high performance kayak, with that as the main priority.
Because carbon fiber is generally used to dramatically reduce weight the layup is generally thin as well. Due to the price, they are usually limited to competitive events. While carbon fiber has tremendous tensile strength it fares poorly in impacts across the grain. A typical carbon fiber boat will act more like a fiberglass boat in an impact situation.
Rotomolded boats are heavy but almost indestructible. There are plenty a stories of an improperly secured rotomolded boat coming off a car at highway speeds, merrily sliding and tumbling down the road, and coming to rest in the median with little more than a few cosmetic scuffs. A carbon fiber boat would likely shatter. A carbon/Kevlar boat would likely suffer extensive damage to the gelcoat and cockpit rim but would appear largely intact.
As stated above "While carbon fiber has tremendous tensile strength it fares poorly in impacts across the grain. " My experience in the surf is that carbon paddles with foam cores are wonderful, just don’t hit them on a rock, they much more fragile than the same dimensioned fiberglass paddle. I owned a carbon fiber surf kayak and it was fairly tough, but brittle for impact.
I also still own a carbon fiber surf SUP, which is carbon over wood and foam cores, and coated with some type of ABS, it’s light and pretty rugged but I have put lots and lots of pretty bad dings in it. I don’t think I would take it down a rocky river, either.
The guy has his reasons for building a boat the way he does, he says to favor performance, but from the river running whitewater videos I have seen , this boy would want something indestructible. Now Olympic Slalom and Freestyle, he has a point.
Like I said to @rstevens15, the Apex style boats would excel in Olympic Slalom and Freestyle, but going down a Whitewater River, I want something indestructible. Those guys bounce off of everything.