Kayaks come in various materials but Polyethylene or plastic as it is popularly known is the commonest. Now, simply stating that a kayak is made of plastic is as vague a statement as saying a pot is made of metal.
It is important to know what material a kayak is made of, but that information is not enough to tell us how the kayak will perform.
Polyethylene Kayaks – 3 Different Material Types
Let’s cut straight to the chase. Kayaks are usually made of one of the plastics discussed below.
High Density Linear Polyethylene (HDPE)
This kind of plastic is the perfect choice for kayaks that are meant for offshore fishing, sea kayaking, and extreme use in the water.
That said, HDPE is more demanding when it comes to molding because it requires extremely high temperatures. The good thing about this is that, kayaks made of this material are not affected by high temperatures when exposed to them.
There happens to be some kind of a tradeoff between HDPE and LDPE when it comes to aesthetic appeal and strength when HDPE is used to make kayaks. HDPE tends to maintain its molded shape and is less smooth while LDPE provides a smoother look due to its elasticity.
Medium-density polyethylene (MDPE)
This is also a type of plastic but is less dense than HDPE. Some of the properties of MDPE include drop resistance and good shock absorption.
Compared to HDPE, this plastic is also less sensitive with a cracking resistance that is better than that of HDPE.
Typically, MDPE or black alkathene as it is otherwise known is synonymous with screw closures, carrier bags, shrink film, and gas pipes.
In the UK, blue and black MDPE is used for wastewater and water plumbing so you can see why the material is ideal for making kayaks.
Low Density Linear Polyethylene (LDPE)
Among the three plastics used to make kayaks, LDPE is the easiest to mold because it requires lower temperatures to do so.
It is also the cheapest among the three so as you can imagine, its memory, UV stability, abrasion and impact resistance, and strength are considerably lower compared to those of HDPE and MDPE.
In China, their products have to hit a specific price point and as such, LDPE has found favor with the commodity kayak manufacturers there.
Commodity kayak manufacturers in China find it easy to copy kayak designs and use LDPE since it is easy to mold.
They do this under employment and environmental conditions that would not be acceptable in the US and UK, but all the same, the kayaks do hit the desired price point.
So What Qualities Should You Look Out For?
Perhaps you are not aware, but checking out plastics can rapidly turn confusing.
With the different plastic types available, different standards of testing, and a variety of quoted prices, it may be difficult to figure out what you are looking at, or even what to look for.
As you analyze a particular kind of plastic for kayak production, you want to look at several properties that are quite easy to measure and all of which have an apparent impact on how the kayak will perform.
The material has to be stiff enough to hold up well in the water. If the plastic is flaccid, it will not even be able to carry you inside the kayak.
The plastic has to be able to withstand impact from water tides and currents if it is to make a quality kayak.
The plastic material you pick has to be able to endure exposure to the sun without being damaged from UV rays.
If not, it will deteriorate quickly over time and that is not a good thing since you cannot avoid exposure to the sun while out in the water.
Are Plastic Kayaks Made from Petroleum?
Answer: Plastic kayaks just like their fiberglass counterparts are made from petrochemicals. And guess what – petrochemicals are obtained from petroleum. In fact, about 8 percent of the world’s oil is used to make plastics. Learn more about how petroleum is turned into polyethylene here.
Also see the following presentation on how crude oil is put to use.
Final Thoughts on Plastic Kayaks
It is important to remember that plastics are not the same so before you go for a plastic kayak, keep the following points in mind.
-Stiff plastic allows for molding of more complicated kayak forms therefore leading to better performance.
-Stiffer plastic resists impact better and is therefore more difficult to break – hence durable.
-Lighter kayaks are made of stiffer plastic. This improves performance, diminishes fatigue, and makes the kayak easy to carry.
-If you care less about durability or resale value, low-grade plastic can be an option because it allows for production of affordable kayaks.
Above all, make it a point to know what you are purchasing. If the manufacturer is unable or unwilling to answer any of your questions in respect to the material you intend to buy, chances are high that the quality is compromised.