Kayak Construction Quality?

Just for fun. NDK and their preferred method of kayak construction has come up numerous times with many proclaiming the pros and cons.



What materials and layups do people prefer or see as a drastic improvement over simple mat and glass layups?



A friend paddles the Bell Magic solo canoe in the Black and Gold layup of Kevlar on the inside and Carbon on the outside. As far as I can see that layup will take a hell of a beating including rock gardens potentially.



Besides poly and polycarbon plastics are there newer materials about to come over the horizon?

I hope salty comes by. He’d want to
say some things about this.



Way back in the 80s, in Boatbuilders Guide, Wallbridge et al described comparison tests and found that an SS/KK layup, or 2 S-glass outer layers over 2 Kevlar inner layers, was about the best they could do. For composite boats, things haven’t changed a lot, at least for whitewater. Carbon is stiffer and lighter than S-glass, but not quite as tough or wear resistant. There have been some cloths testing out better than Kevlar, but it seems they either cost too much or are hard to lay up, or something.



About all the various solid plastics I don’t know enough to comment.

Still your best bang for the buck
is vacuum bagged or infusion glass cloth, IMO. Tough, durable, and easy to repair in most cases.



There are lots of different materials you can lay up with resin and make a really great boat, but there is a cost to most of them - either in dollars or properties. You can literally build a super light, tough kayak, but it might cost $10K to build, especially if you’re using exotic materials in the layup.



Kevlar will save you a couple of pounds and add some puncture resistance, but it will cost you about $500 on average (And you still have to repair the boat when you get back to shore, and probably duct tape the damage out on the water anyway, so what have you saved?). Carbon will save even more weight, but can be brittle in heavy impact situations, and costs even more than kevlar. But for most paddling mortals, good ole glass is plenty good, and affordable.

What about thermal formed?
It is a tough material and is now coming out in a thicker stock in the new Rockpool and Valley thermal formed hulls. Does anyone have practical or scientific experience with this material? Bill

Thermoformed plastic
I have a thermoformed plastic kayak from Delta and it is really tough material.I have smashed it in to rocks and have even dropped it while trying to load it and it was unscathed. The weight is comparable to a fiberglass boat but the cost is less expensive…

That might be one of P-net’s best posts.

While the fabric used is important…

– Last Updated: May-16-10 8:32 AM EST –

...so is the resin. Most kayaks are now built with vinylester resin, which is significant step up from polyester resin. However, epoxy is the best in terms of strength. Again, look at Patrick's videos on the Tideline site. IIRC, that hull is S-glass and epoxy. Perhaps Patrick can jump in here with some details.
http://www.eteamz.com/paddleshop/news/index.cfm?cat=204763
http://www.eteamz.com/paddleshop/news/index.cfm?cat=204763

Considering that epoxy is more expensive than vinylester resin, but S-glass is cheaper than Kevlar or carbon fiber, I would think that S-glass/epoxy boats could be built for no more than the price of Kevlar or carbon/Kevlar boats.

Here's another video with some torture testing. It's not an epoxy boat, but it is a high-quality, resin-infusion layup.
http://www.youtube.com/watch?v=7dtk818WSiU&feature=related

I think it's also important to note that the boats in these videos are very light, in addition to being really tough. Contrary to what some people would tell you, a boat doesn't have to weight 60+ pounds to be durable! This illustrates what's possible using quality materials and manufacturing techniques.

A new folder
http://tinyurl.com/25odkhn

layup for strong/light kayaks
Charlie Wilson, formerly of Bell Canoe, former co-owner of Placid Boatworks and now consultant to Colden Canoe is a friend and I own a BB Rapidfire. While not an industry insider, I have spent a number of days at the PB workshop watching their construction process.



With that disclosure statement out of the way, and with the acknowledgement that construction of composite kayaks is more difficult than composite canoes, I think selecting particular fabrics, deciding where to place what fabric type, what resin to use, and what process to use with that resin could be the same for a kayak as a canoe.



PB uses many pieces of fabric, each placed in strategic locations for specific reasons. They use vinyl ester resin in a vacuum infusion process to make the hull. Building a deck would more than double the time necessary to form the components of a kayak (hull and deck). Time required to join the hull to the deck and outfit the kayak would increase cost vs. a high tech canoe such as PB makes and their canoes, while worth the price, are expensive.



This brings us to the major drawback of a kayak made in such a way: The COST factor. The cost of more sophisticated materials, the increased labor cost, the possible need for better molds or earlier replacement of molds (I’m just speculating here), the time required to set up the vacuum system and chase down leaks before beginning infusion would all add to final cost.



So, can a stronger and lighter kayak be built with present materials and processes-Absolutely. Are there enough paddlers willing to pay the much higher price for such a strong and light kayak? My guess is NO. Go to any paddlesport dealer and count the stocked models in plastic and then count the stocked models in composite and you can see where the majority of the buying public is putting their money. Go to a box store (where many of the new “kayaks” are sold) and try to find one composite kayak.



A few brand name kayak builders periodically try to make a very light version of a few models but they are rare, very expensive and often not much lighter. My hope is that a few niche kayak makers will take the risk to try to successfully produce a lighter and stronger kayak. I am aware that Sterling is said to produce such a kayak, but here in CT I’m on the wrong coast to see his kayaks, let alone try one. Patrick Cooley made strong light kayaks (Tideline), but he sold his molds and now concentrates on paddle construction, which needs less space and is probably more lucrative from a time consideration in a one man shop.



Dave






The thing is…

– Last Updated: May-16-10 12:18 PM EST –

...that kayaks are already being built this way and the prices are comparable to kayaks built using more "primitive" methods. For example, the Necky Chatham 16, 17 or 18 is $3000 for glass and $3500 for carbon. A Romany or Explorer is $3100 for standard glass, $3400 for "Elite" and $3700 for Kevlar.

In other words, superior construction and lighter weight doesn't cost extra, it's actually slightly cheaper in this particular case. Why anyone would pay higher prices for seriously inferior construction is beyond me.

Cool!
I guess for $200 and 2 hours of construction time, he at least got something really novel. Ya gotta’ give him kudos for creativity!

even the lightest and strongest
layup ever will still not transform a necky from a slow as hell, poorly designed piece of garbage into a kayak. Those have to be my most hated boats. No wonder the guy is pounding it with a hammer.

On epoxy versus vinylester, I have
two boats with heat-cured epoxy layups, and at least three with vinylester layups. I believe in epoxy, and I’ve seen study data showing some advantages to epoxy, but in whiteater hammering, vinylester seems to stand up about as well as epoxy.



So while I might pay extra for an epoxy layup, if it is offered, I would cheerfully buy a vinylester boat, especially if the best cloths and methods are used.

weight of Necky carbon Chatham vs, ?
Hi Brian,



You are focused on NDK’s primitive construction and poor quality (a worthy topic) while I was posting on possible ideal construction and the cost/sales of that hypothetical kayak.



I do like NDK hull shapes. However, after seeing some of their worst efforts, I would be the last person to defend their quality. A Explorer I bought used needed the seat hanger repaired. My neighbor’s Romany just had its seat hanger break. NDK kayaks have had this seat hanger problem for many years and have not changed construction to fix it. I saw an attempt to build a carbon Explorer that was warped and so soft that one could dent it anywhere by pushing on the hull. A Romany elite that I bought used is functionally ok but has to be on the list of ten worse individual kayaks ever built for cosmetic considerations. There are also a couple of soft spots and while lighter than their normal construction, it also isn’t all that light. So, I’m not a NDK defender.



I’m just not that impressed with 46 lbs for a 16.5 carbon kayak. I’ll agree that $3500 is a good price for a carbon kayak. Better than NDK on price and weight? Yes, but that’s choosing a easy target. A 16.5’ kayak could be built lighter yet and still be stronger if built in the way I posted. As an example, I have a epoxy/glass Tideland 19 kayak which is 18’ 10" long and yet weighs only 42 lbs. Over 3’ longer and 4 lbs lighter than the carbon Chatham while being made of glass not carbon. (However, the Tideline doesn’t have a skeg, which moves the weight comparison a bit closer). I think a 16’ kayak could be strongly built weighing 35-40 lbs. I’m also sure this hypothetical strong/light kayak would also cost more than $3500 unless built in China (which I’m not advocating).



Dave

Just not for you
Funny that what may be the toughest sea kayak race put on by the Tsunami Rangers in California was won by a paddler who chose to paddle a Chatham 16???



Oh, but he was a good paddler… No bad kayaks really, just bad combinations. I’m guessing your a flat water guy.

So yesterday I show up for a once a
year group paddle in my city. Some guy walks up to me as I am packing my Romany Surf for the paddle. Two people have gathered around in advance of this to ask me questions about my GP’s. This guy walks up and says “this boat is made in Wales by the worst quality kayak manufacturer in the world, I hate Valley boats!”. It was obvious to me that I was in the presence of kayaking royalty and should remain on my knees. I said “yes NDK certainly is at the back of the pack in terms of quality issues, but they built a fine boat for me”. He said “well I think Valley sucks”. I said “you realize that this is not a Valley right?”. “Oh, uh…, well…uh…Valley still sucks”. Okee dokee. It is nice to see the one can be a moron as well as an opinionated moron. I spent the rest of the day trying to keep away from this genius only to find him still ranting about Valley whenever I was in ear shot. Apparently he felt he was screwed by Stan at GRO in 1996 when he and Valley refused to repair or replace a leaking hull. The fact that it happened in 1996 must expalin why he cannot tell the difference between a Valley and an NDK. Bad experiences seem to stay in the memory longer than good ones, or at least are talked about more often.

I guess it was good that I left the Nordkapp and the Aquanaut at home because they suck. :slight_smile: Bill

How do we explain thermal formed boats
at $3,000? I am guessing that the sheet stock is very expensive and so are the tools, because the labor sure isn’t. If material cost equates to better quality, these boats should be best in class? Bill

Weight vs. durability
Even with quality construction, there is a trade-off. Also, Patrick uses epoxy in his boats, so he can make them lighter without sacrificing strength. I also suspect that his customers understand that they’re not buying a boat that’s going to take a lot of bashing and abrasion without needing to have the surface repaired regularly, much as is the case with light race boats. I’m guessing that Necky probably expects their boats to be used by more mainstream paddlers and they build them heavier to handle a fair amount of abuse and make them more carefree.

Amortizing the tooling

– Last Updated: May-17-10 10:15 AM EST –

It's probably similiar in cost to rotomolding equipment, but the market for the boats is smaller, so it takes a higher price to pay for the tooling in a reasonable time frame. As you said, the material is also more expensive than polyethylene, so that's going to drive the price up, too. The boats require joining the hull and deck and the same type of outfitting as composite boats, so there's no savings in that part of the process. There may be a component of seeing what the market will bear, as well.

There’s nothing wrong with vinylester…
…and I didn’t mean to imply that there is. I wouldn’t hesitate to buy a boat built with it, especially since epoxy construction is pretty rare in the the industry.