Material Science in surfboards
During my recent visit to the American West Coast, I had the opportunity to have a first contact with surfing. Although I didn’t have a totally satisfactory experience, I must say I found this sport quite interesting and, for that reason, I started asking some questions about the materials which are used to manufacture surfboards to my surfing expert brother. In this post I will introduce very briefly the main materials and a bit of comparison between their performance.
To begin with, the surfboards can be classified in two main categories with regards to the materials used in the outer part. For people who, like me, are not familiar with this sport, the way for identifying which of the two types of surfboards is in front of us is simply to look at the external appearance of the board itself. Trust me, anyone can spot the difference!
The first type corresponds to the surfboards made of glass fibre. This boards have been around for over half a century and this fact makes them be considered as the traditional board. The inner part is made of polyurethane (PU), a polymer which stands out for being lightweight and providing a good buoyancy to the final structure. Usually a wooden element is embedded in the core in order to increase the stiffness of the product. Then, the whole thing is surrounded by some layers of glass fibre cloth which provides the strength and resistance to the board. The amount of fibres and their orientation can vary from one surfboard to another, resulting in different strengths and stiffness without changing the weight of the structure too much.
Then, we have the epoxy boards. The first thing we notice about this category is its plastic exterior appearance. In this case, the core is made of polystyrene (PS) foam, and it is worth saying that depending on its type, the foam will absorb a different quantity of water. This material is also the responsible for the buoyancy of the surfboard. Then this core is coated with an epoxy resin, being this the reason behind its name. Another option within this category is the use of an expanded polysterene (EPS) foam core, which is an even lighter material that we can find, for instance, in bicycle helmets. It should be said that the use of this kind surfboards was not very extended until they started appearing in main events where professional surfers had a great performance.
If a comparison is to be made, we could say that the epoxy boards are stronger than the glass fibre ones. This is a reason why a lot of people recommend PS/EPS as a better option for beginners, since the PU ones are more likely to suffer damage. In terms of buoyancy, the epoxy surfboards present a better capability for floating and, besides, it helps rookies to catch waves. However, the fact that PS/EPS boards present a better buoyancy does not mean that they are better, since manoeuvres such as duck diving (a technique which is used to avoid a wave when you are paddling) are much easier when traditional glass fibre boards are used. What is more, some experts feel like PU boards allow them to perform better when they try difficult movements. Apart from that, it is a fact that the epoxy ones are way more lighter, what represents a clear advantage. Finally, in terms of the price, the glass fibre boards are now more affordable than they used to be, what is also caused by the fact that the materials required for the manufacturing process of the epoxy boards are more expensive.
Apart from those two main categories, it should be stated that there is a new type of surfboards called soft top. In particular, these boards are basically made of cork and they have been thought for beginners. On the other hand, they are heavier than the other two categories presented above. Apart from being “safer” and heavier than their “hard brothers”, they usually come with warranty (yes, it is remarkable since the others don’t) despite the fact that they present long durability. In addition, according to experts, their performance is more than acceptable even though they are designed for rookies.
I hope you enjoyed this “summer” reading and please, if you know more about this topic, don’t hesitate to comment! As I said before, this has been my first surfing experience!