The composite surfboard is a common place in the sport today. Ever since the introduction of fiberglass composites after World War II, the surfboard industry was truly one of the first to embrace composites.
Prior to fiber reinforced composites, surfboards were manufactured out of wood and could weigh over 100 lbs. Today, a composite surfboard the same size (10 feet) might weigh less then 10 lbs. To shed this enormous amount of weight, surfboards took advantage of 3 key materials:
Polyurethane foam became the core material of choice for surfboards. It is lightweight, provides thickness, and provides buoyancy. The foam core of a composite surfboard is sandwiched between FRP skins and creates the stiffness and structure of the surfboard. Often, a "stringer" of wood is bonded in the center of the board to provide increased rigidity, much like an I-beam.
The surfboard foam industry was dominated by the company Clark Foam up until 2005, at which time the owner decided to shut down with no prior warning. Today, the foam core for composite surfboards is primarily polyurethane foam. However, expanded polystyrene (EPS) is being used more often as the use of epoxy resins increases. Regardless of the foam used it almost always closed-cell, so that it does not absorb moisture.
Thermosetting resins have been key to the success of the composite surfboard. Even when boards were made of wood, resins and coatings were used to help prevent the boards soaking in water. As resin technology continues to improve, boards are able to become stronger and lighter weight.
The most common resins used in composite surfboards are polyester resins. This is primarily because polyester resin is inexpensive. Additionally, resin manufacturers have perfected their polyester surfboard resins so that they are easy to work with and are crystal clear.
It is important that the resins used are water-clear, because a surfboard is as much a work of art as it is a functional piece of equipment. As surfboards age, they turn yellow from the UV rays. Hence, UV resistance is an important factor to the resins used today.
With the advancements in resin technology, it is no surprise composite surfboards are being manufactured with epoxy. Epoxy has no VOC emissions during the manufacturing process, and it has much higher strength, fatigue, and impact resistance properties. However, the only current downside to using epoxy is, these boards tend to turn yellow faster then polyester boards. Although, this may soon change with improved formulations.
Fiberglass is the structural backbone to surfboards. The fiberglass reinforcement provides the structure and strength to the board. Most commonly, lightweight woven fiberglass cloth is used as the reinforcement. Usually, it is between 4 and 8 ounce fabric. (Ounces per square yard).
Often more then one layer is used. Currently, the weaves used are evenly balanced with equal amounts of fiberglass running from nose to tail, and rail to rail. However, engineers are designing boards with different amounts of fiber running in different directions. This provides the strength and the rigidity where required, without adding much additional weight.
Future Of The Composite Surfboard
Surfers are known for being progressive, and with this comes experimentation with different shapes and materials. Boards today are embracing composite technology and new materials. The composite surfboards of the future are incorporating fibers such as Kevlar, carbon fiber, and Innegra.
The various properties of the many composite reinforcements available can allow the surfer or engineer, to tweak the properties to help create the "dream" board. It also makes a surfboard extremely cool looking to have unique materials and construction.
The various properties of the many composite reinforcements available can allow the surfer or engineer, to tweak the properties to help create the ultimate surfboard. It also makes a surfboard extremely cool looking to have unique materials and construction.
Not only are the materials being used changing, but the method of manufacturing is evolving as well. CNC machines are commonly being used to precisely machine out the foam core. This creates boards that are almost perfectly symmetrical and exact.
At first, the fear of mass production brought concerns of removing the "soul" from the sport. Meaning, the traditional method of hand shaping boards is being reduced to the job of a computer.
However, the opposite seems to be true. Custom boards, which are truly works of art, seem to be as popular as ever. And with composites, creativity in methods and materials to laminate boards seems to give an endless opportunity to customize and personalize boards.
The future of the composite surfboard is bright. In the 1950's the use of fiberglass was revolutionary. The new pioneers will continue to push the envelope and will embrace the next generation of composite materials and processing techniques.