Would love advice on both layups. Looking to upgrade my kayak from a poly touring to a FG or K/C layup. I was only looking at FG, but there are some decent options on the used market that are K/C as well. I won’t be rock hopping or surfing near coastlines where landing on rocks will be an issue.
My paddling included day, weekend, and the odd 4-5 day tour. I’ll be pulling up on smooth rock shorelines, not aggressively, but up until now have been able to drag my loaded kayak up 10’ out of the water.
In a NDK, P&H or Sterling kayak, how fragile is the K/C layup? How babied do I have to treat it?
Weight savings is a minor plus, but coming from my 69 lb 17’7" kayak I have now… anything is lighter. I’m leaning towards FG for sure, but as I said, there are some good used options out there.
P&H plenty rugged in the carbon/Kevlar layup for expedition type use. I probably know of a carbon/Kevlar Cetus LV coming on the maker in the near future if you want to make the road trip to Hyde o Park, NY.
For either layup, but particularly the K/C, I would add a keel strip if there isn’t one. If you don’t abuse the kayak, the Keel Eazy product is robust enough, Maybe $4 per foot and not difficult to install.
The difference between plastic and composite has to with rigidity. If you try to push either past their flex point they will break. So the two media have different uses, unless you want to defeat the other selling point of a composite, weight.
All manufacturers have different ideas about strength. I was at the unveiling of a new Necky race boat back around 1990. It was a k/c weave, and all that. It still weighed in at over 50 pounds because they built it like a motorcycle helmet.
On average k/c weave saves about 40% of weight because it does not take as many layers, so there is less adhesive used to hold it together, and most use a pre-impregnated cloth that can cut weight even further.
I have a 19 foot boat that weighs 26 pounds and has been over logs, the Big Shoals on the Suwanee, and numerous other things the builder didn’t expect it to encounter. It is still whole and still performs well.
Even though you are not looking for weight reduction, you’ll appreciate it when moving from RM to FG and, even more so, to K/CF. Sounds like “impact durability” is not an issue for you, but you will get crisper handling from a stiffer composite hull, provided the hull design is suited to your preferred venue(s).
For me, i really enjoyed surfing (my preferred paddling venue) with my RM Delphin 150. The Delphin’s 55 lbs didn’t bother me too much since I was still able to cartop on my own (I usually paddle alone and have no help). The long carries to the water line at a beach break, especially on a low tide, were kind of a pain. I usually had to drop the Delphin down for at least one or if not two breaks on a 100 yard plus carry. Not too horrible with a RM kayak. Just drop the damn boat! However, when I got my K/CF surfing longboat (39 vs 55 lbs)… Wow… The should carries and cartopping was so much easier. I can carry without stopping from car to the low tide water line without breaking a sweat (or feel the pain on the shoulder). Of course, the most important thing was dramatic increase in performance. Both because it is stiffer and lighter, and because it has a much more surfing oriented hull design.
Toughness… I am still not quite confident of taking the K/CF boat out for rockplay (mostly because I am alone and can afford a puncture). I totally trust the boat for surfing beach boats. Actually, this past weekend, with the waves breaking (and dumping) right on a cobblestone shoreline, I blew my attempt to get off the wave before it broke. So, I went down the falls and ended up sidesurfing right onto the cobblestones. It felt like riding my bike over some of Boston’s historic cobblestone streets. Not pleasant and much louder with hull bouncing over the stones. However, when I checked the hull after the session, I had a couple of speck size chips from the gelcoat, but not damaged to underlying fiber. Had it been with my waveski (epoxy over styrofoam), I would have been replacing at least one fin box and a cracked rail.
Can’t say if I fully confident about rock play, but I expect to be a little more adventuresome with it when I go out with the RICKA surf and rock play contingent this coming warmer season.
I have hulls with FG and some with Kevlar . Same hulls same manufacturer and stiffer is better. About 4 pounds difference.
Hard to compare different manufacturers. Different layup schedules as said above. I stiffened some of the hulls behind the cockpits and in cockpit areas. I do that because I come home and end up see sawing over a bulkhead which can be 5’ high. Only adds a pound or a bit more.
You for your use most any major brand will work. Pick the kayak you like best and are happy with the price. You can feel stiffness in a hull just by pressing it with you thumb in critical areas with wide spans.
Unless it was built as a requested super light they should all be fine.
Most canoe manufacturers have an explanation of their lay-ups.
Typically carbon/kevlar boats are stronger than FG and lighter too but as others have said there are exceptions. The kevlar in a C/K lay-up adds resiliency; FG lay-ups tend to be more brittle. If you plan to drag a loaded composite boat over rock I’d prioritize a strong lay-up with a thick gelcoat over light weight, I don’t baby my canoes but that’s one thing I avoid.
Besides the lower weight for Kevlar or carbon/Kevlar vs fiberglass there is also the increased cost, sometimes considerable. The advantage of Kevlar is that if you pile into a rock with a Kevlar boat you may cause considerable damage to the gelcoat but you are unlikely to puncture the hull. The boat will still be relatively seaworthy enough to get you home or to shore. With fiberglass you are likely to put a hole on the hull.
I have seen a Kevlar boat where a bow tiedown with an open hook came loose and was caught by the front tire. The boat was bent 90° and broke the windshield, but the hull was still watertight. Straightened out all that you noticed was that the gelcoat was cracked in multiple places. A fiberglass kayak where the same thing occurs will often break in two.
While fiberglass is relatively easy to repair Kevlar is very difficult. Kevlar cloth is almost impossible to cut and the cloth itself will fuzz up if sanded. Most boat yards will not do repair on Kevlar hulls if it involves more than simple gelcoat repair.
Carbon fiber is lighter than Kevlar but is very brittle. That is why it is often used in combination with Kevlar.
Yes as @rstevens15 says, a kevlar/carbon boat will typically have much higher survivability than fiberglass. I have a c/k canoe that has taken two separate very hard direct hits on rock and the fabric was untouched. But most newer canoes have thin gelcoats or just skincoats to make them light but as PD says they are still pretty easy to repair.
I don’t know if some kayaks are built with foam cores like many new canoes but a foam core is one thing you do not want if you are pulling a loaded boat over rock. They can dent or crease pretty easily.
Kevlar and carbon fiber can be repaired, but it’s much more difficult than repairing fiberglass, and unless you want to attempt to do it yourself the labor costs can be very high. Boatyards around Annapolis do not want to deal with something as small as a kayak for carbon/Kevlar for a major repair. They’ll usually tell you it’s not worth it. Of course it’s rare that the fabric itself will be damaged.
When you get to something as expensive as an offshore race boat, then it can be worth it.
If the damaged area is small, then a Kevlar patch overlaid with fiberglass can sometimes be used. With fiberglass you can often return a hull to near original appearance if you are skilled enough but carbon/Kevlar repairs are difficult to do that and generally add weight and are not as strong at the site of the repair.
Better watch Turning Point Boat Works. They have many videos on YouTube showing most of the repair process. They hold a few secrets off the video.
Done properly you gain no weight or so little it would never matter.
Boat yards have bigger fish to fry than fixing kayaks. Around Annapolis they are laying people away I’m sure.
If repairs were not as strong on race boats they’d just come apart again easily. Yes they do worry about weight also.