Golden Gate Kayaking
Kayak Buyers' FAQ
by Jim Westcott
How will a plastic boat differ from a fiberglass boat?
Most plastic kayaks are polyethelene or polythene and are produced using a process called roto-molding creating a substantially cheaper and very durable kayak. Many manufacturers are giving a fancy name to their plastic material for marketing purposes but most are realistically pretty similar. The negatives are that plastic kayaks are often substantially heavier, will distort easily in heat, will scratch much deeper and are therefore noticeably slower than the same kayak in fiberglass. They are however, an excellent choice for knocking about in the surf zone or rock gardens and will perform reasonably well for most other aspects of sea kayaking at a much more affordable price.
How is a kevlar boat different from a fiberglass boat?
Kevlar kayaks are made using a sandwich of fiberglass and kevlar fabrics bonded together with vinylester resin. There is almost always a fiberglass cloth of some type as the outside layer(s). Because kevlar is much higher than fiberglass in stiffness and tensile strength, the builder can use fewer layers of cloth and in turn use much less resin reducing weight by approximately 15-20%. Kevlar is much more expensive than fiberglass and much more difficult to repair. It can be easily recognized by it's gold color.
Will the kevlar boat be faster than the fiberglass boat?
Not enough to be very noticeable. In fact they often can be much more affected by high winds while day-tripping. Unless you are an avid racer, the best reason to buy a kevlar kayak is the advantage of lighter weight when loading and unloading onto your car and carrying the kayak to the beach. If these reasons are not an issue, save yourself a bundle and get a fiberglass kayak. You can get some really nice accessories with your savings!
Will a kevlar boat be stronger than a fiberglass boat?
The short answer is no! This is in part because they use substantially less material in the kevlar kayak to reduce the weight. Kevlar is very high in tensile strength but relatively low in compressive strength. An all-kevlar boat would show initial damage fairly easily from a hard blow. The damaged cloth might stay together even though much of the resin around it will have fractured. If you expect to use your kayak in the surf zone or around rocks, kevlar is not a good material choice.
How is a carbon fiber kayak different from a fiberglass or kevlar boat?
There are a few manufacturers building "carbon fiber" kayaks. These kayaks are also typically a sandwich of fiberglass, carbon and other cloths. You can tell the carbon fiber by the jet black color resulting from the process used to make the cloth. They are almost always left visible by using a clear resin to the outside showing off the hi-tech fabric. Carbon cloth is very stiff (stiffer than kevlar) but lower in tensile and compressive strength. The advantage to carbon is the chance to use even less material than a kevlar boat resulting in even less weight. These boats tend to be very costly and brittle.
What are the characteristics for a carbon/kevlar kayak?
Many of the manufacturers from Europe are producing kayaks using carbon and kevlar woven together. This fabric is even showing up in some boats made in North America. As you can guess the fabric takes advantage of properties from both materials creating a lighter weight kayak that is quite stiff although not quite as strong as the same kayak in a fiberglass lay-up.
What is the Diolene material used in many of the British kayaks?
Diolene is a polyester fabric with higher impact and tear strength than fiberglass cloth. When sandwiched with fiberglass materials, it produces a slightly tougher kayak for the same cost as fiberglass.
If I wax my kayak, will it be faster in the water?
Surprisingly, wax on the hull disturbs the laminar flow of the water molecules as they move past the hull slowing the kayak. This is not something you would really notice but if you plan on racing, don't do it. Most automotive and boat waxes do offer a certain amount of UV protection so waxing the deck will make it look nice and give it some protection from the sun.
What do I need to do to care for my kayak?
Rinse your kayak often with fresh water- especially any skeg or rudder cables and fittings. Salt build-up on the cables is one of the major causes of failure for both. Leave the hatch covers off during storage. If they are rubber like the hatches on the British kayaks, treat them with 303 protectant as often as you can force yourself to in order to keep them from drying out and cracking. Look for 303 protectant in any good kayak or marine shop.
Can I store my kayak outside?
You can store your kayak outside but it would be best if you kept it covered with a loose tarp to keep the sun off of it and remove the hatch covers to prevent excessive temperature extremes inside. Do not let your fiberglass kayak sit in the back yard full of rainwater. Fiberglass is porous and will absorb water adding substantial weight to the boat permanently!
Should I care if the kayak I buy has fiberglass or foam bulkheads?
In my 10+ years of kayak repair experience, I have found that foam bulkheads often begin leaking within a few years. This is due to the fact that the foam shrinks with age and pulls away from the adhesive used to seal the edges. These leaks are annoyingly persistent even after re-caulking and I often had to replace the foam bulkheads with fiberglass bulkheads at great expense.
What else should I look for in a new kayak purchase?
Check to see how the deck and hull were seamed together in fiberglass and kevlar kayaks. Some manufacturers use seam tape and resin on the inside and the outside providing a mechanical bond to both sides. Others use a plastic narrow H-shaped moulding with a fiberglass tape on the inside. The plastic moulding only aligns the two parts and offers no mechanical bond of its own. This method results in only a mechanical bond on the inside only which is not as strong as fiberglass seams inside and out.
If the kayak is to be used on the open sea or large bodies of water, we recommend at least two hatches and bulkheads (fore and aft) that are nearly watertight or 100% watertight. Most experienced kayak instructors will admit that performing a T-rescue or other rescue of a swamped kayak with float bags as a replacement for a hatch and bulkhead can be problematic and extremely difficult in rough conditions. The use of a sea sock to keep the water out of the cockpit has often proved problematic as well. A boat with leaky hatches can quickly become a bear to empty when the %&@ hits the fan as well.
Push on the deck to see how flexible it is. It should feel pretty robust. We have often seen lightweight kayaks from the US and Canada that damaged quite easily when performing a simple T-rescue in flat water.
Kayak design is an extremely lengthy subject that could be debated endlessly. Our best advise is try before you buy and if possible try the kayak in conditions you are likely to be paddling in. It would be good to discover how the boat performs in wind and waves. Some kayaks perform well in flat seas but are an absolute nightmare in following seas! If you are a new paddler, you may not have developed the skills to paddle in these conditions yet and will have to rely on the recommendations of others. Just remember, most paddlers that have recently spent thousands of dollars on their kayak will be hard pressed to say anything bad about their kayak out of pride and a need to feel they themselves made a good purchase.
Above all else, buy a boat that fits you and your style of paddling!
Each model is built for a range of paddler sizes. If you feel like you
are sloshing around in the cockpit, you will have poor control of the
boat with your lower body. Since your contact with the kayak is with
your feet, thighs or knees, hips and butt, this will seriously inhibit
performance of your boat with you in it! If you expect to be paddling
regularly with a group of kayakers that all have long, sleek (17-19')
kayaks, that 14 footer that is on sale at your local kayak shop could
prove to be a big mistake since it will undoubtedly be considerably
slower. On the other hand, don't be coerced into buying a great big
expedition boat for a trip that you might do someday if 95% of your
paddling is day tripping. You can always rent or borrow a bigger kayak
if you ever have the need.
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