Warning: theoretical content ahead.

Carbon boats have been used succesfully in many branches of the kayakking sport for years. And some time back someone out there decided that freestyle boats where next. These new carbon boats are more expensive, but also ridiculously light for better performance. Carbon has a weakness however, it's extremely strong but also very brittle, it will rather break than bend. For playboats, this means that you can't really take them anywhere where you might hit a rock while pulling your moves, rocks are the mortal enemies of carbon. Even just hitting the water in the wrong way can put a lot of stress on carbon.

Plastic has less problems with sudden forces, it's a more relaxed material that will go with the flow (dude). Okay, it dents and deforms over time, but it stays in one piece. I like stuff that stays in one piece, especially when it concerns my boat. However, to get a plastic boat up to strength you need to use more material, which means the boat weights more, which in turn causes the competitive paddlers to turn to carbon.

What I was wondering about is wether you couldn't make a lighter plastic boat simply by using a better plastic? We've seen the difference it makes if manufacturers use crosslinked polyethylene instead of the regular variety, but why stop there? After all, PE is probably the most used plastic in the world by far because of the price, not because of the strength. Other plastics would, at least theoretically, perform better. One contestant for instance would be polybutylene, which sees a lot of use in pipes for being better able to stand up to both sudden shocks and bumps as well as the long term effects of water pressure. That sounds like kayak material to me.

The questions that matter of course are how much stronger and/or lighter a boat could be made using a different plastic and how much that would cost. In short: would the product be competitive in a market with both standard platic boats and carbon boats available? And since I'm probably not the first person to think of this, I have a daunting feeling it is not. I'm not sure though. So is there anybody who has heard of experiments with different types of plastics in the past? (Anyone from a manufacturer's team that has ever tested them perhaps? [/wishfull thinking]) Anyone with reasons why it would or wouldn't work? Any other stuff to add? Anyone feeling like posting in the gear subforum but not looking to give advice on which boat to buy? This is the place.

saw a guy at the british champs 2 weeks back paddling one looked a bit quick to handle

Don't forget stiffness. That makes a big difference to the performance too. Composite boats are great, but they cost more to buy and as mentioned, they don't like rocks. Moulds for them are cheaper to build than casting aluminium moulds for plastic kayaks...

There are better plastics available. BUT....

Blow moulded kayaks are much stronger. BUT the moulds are very expensive (VERY) and as far as I know one cannot do proto's - I stand, as always, under correction. The plastics which are 'better' are just not suitable for roto-moulding. It's the nature of the beast

If you want to study it more in-depth, start Googling how they make large plastic water tanks. The debates rages with cross linked versus superlinear or normal PE...blah blah blah More rejects with cross linked but lighter, but then more brittle too.

For food for the brain:
www.useakayak.net/equipment/boat_constuction.html

and:
www.rotationalmoulding.com/index.php?pageType=main&NEWnavNum=5

and:
en.wikipedia.org/wiki/Rotational_molding

Good thread. Plastic will always take the market share. Cheaper and tougher. Composite boats will also always have a market too, just smaller, no doubt. I love my composite Element but I won't surf serious point breaks because if the decks bursts, the kayak goes to the rocks and it's goodbye boat. Each type has their place

But to answer your other questions, I think in the future we can only hope the chemical engineers come up with something great. Because right now there isn't a plastic which will result in lighter and stronger boats. And if there is, and anyone knows, please tell us

Carbon boats have 2 advantages. They are stiff and light, both helping with performance. The downsides are cost, and they don't like rocks.

For this reason, I think the only people who these are suitable for is top athletes looking to win comps. Not your average playboater.

If you managed to make a slightly stronger boat with some better plastic, you're still probably not going to sell a great deal if they're a few hundred more than any other boat.

The question I always have is, are carbon boats good for the sport or not? They help top athletes do some fancier tricks, which might help appeal to a wider audience and bring more people into the sport. On the other hand, if it come's down to needing a super expensive carbon boat to be competitive at local comp's, only the well off will have a look in.

I think they're a good thing. They make paddling fun, and having fun is the point to paddling in my opinion.

In competitions, I do think that composites should not compete against plastic boats. It definitely isn't fair. There should be a separate category. It would be interesting to hear some more opinions.

I don't think they should have their own category. Kayakking is a sport in which your gear makes a difference. If you have a plastic boat, you're disadvantaged, but the same goes if you're not paddling the newest boat design, or if you have a cheaper paddle than the rest. The sport will always be unfair to a point. Even if you have all the funds in the world you can still end up with "lesser" gear than your competitor because the newest boats simply aren't build in what you would consider the perfect size.

I'm by no means a competitive paddler, I'm quite happy just boating arround a bit, so I'm not the best judge of what competition rules should be, but I think it's a lot easier to accept that certain boats are simply uncompetitive than to give them their own competition. Otherwise we should already have three of those: oldschool, newschool and "we don't know how to call this one because we named the last one newschool"-school. Carbon could be the fourth then...

Also: thanks for all the info on the materials and moulding techniques Adrian. That does shed some more light on the matter. It does seem whe're a bit stuck with normal plastic then for the moment. Ah well, it works good enough, so I really shouldn't be complaining...

Yes, it is true that carbon boats are more expensive and much more brittle. But what some people don't know is that once a carbon boat cracks, it's not trash. If the break isn't too bad, it's actually relatively easy to repair it if you know someone who can work with carbon. (Yes I know, not a lot of people are experts with carbon, but your local road bike shop may be able to help). I can't really speak for these boats as I don't own one, nor do I know anyone that owns one, but that is what I have heard from fellow kayakers.

While carbon can be repaired easily, putting a repair on the hull will break up the planing surface, unless polished perfectly. Plus, impact with rocks is a given on the majority of rivers (exceptions would be artificial parks and playspots). Carbon makes sense in road bikes because the chances of it hitting the ground are slim, and in sea kayaks because there's not very many unavoidable rocks in the ocean (a few, but not many). Sure, a carbon creekboat would be nice for those long hikes, but the durability is lacking. Plus, even with the playspots that exist, most of them still are fairly rocky. At the USNWC, one of the most popular playspots (because of really good eddy service, and weaker currents) is still shallow. Paddling a carbon slalom boat there is logical since the main aim is to go downriver, but with a playboat, especially a carbon one, one mistake could crack your boat. And, for the vast majority of us, we won't see the difference in a carbon boat.