The difference between epoxy and PU (Fiberglass) surfboards

Last updated on: September 2, 2022
epoxy surfboards vs pu surfboards

What are surfboards made of?

The original surfboards from Hawaii were made out of wood, but as time and technology proceeded, new types of surfboards got invented using the foam materials that we know today.

Surfboard materials and construction

A surfboards consist of four main materials, which is

  • A foam core
  • A stringer
  • Fiberglass cloth
  • Resin

The main part of a surfboard is the foam core. The two most popular types of foam materials used in surfboards are:

  1. Polyurethane Foam, used in PU surfboards
  2. Expanded Polystyrene Foam (EPS), used in Epoxy surfboards

A thin piece of wood called a stringer is used in most surfboard constructions. The surfboard stringer runs in a vertical line through the center of the surfboard and provides stiffness that helps the board from not breaking in half.

After the foam blank is shaped, it’s time to cover the surfboard with fiberglass cloth, and finally, it gets sealed with resin. This process will form the hard outer shell.

There are two different types of resins used for coating. These two types of resin also define the two most popular surfboard types. The first type of resin is Epoxy, hence the name of epoxy surfboards. The other type is Polyester resin, which is used on PU surfboards.

surfboard foam

Clark Foam

In 2005 Clark Foam, the largest blank manufacturer in the world, closed down suddenly. This caused a rupture in the surfboard foam business, and many people started manufacturing their own. As smaller establishments started upping their production scales and fulfilling the demand, so there was a small gap for epoxy surfboards to fill the emerging space.

Epoxy surfboards vs. PU surfboards

Epoxy surfboards comprise an expanded polystyrene Styrofoam (ESP) foam core, coated with an epoxy resin, the only resin compatible with this foam blank.

Fiberglass surfboards are also known as PU surfboards, the regular boards that most surfers grew up with. These surfboards comprise a polyurethane inner, which is then wrapped in fiberglass cloth and sealed with a polyester resin. 

Characteristics of the two

There are many differences between the handling characteristics of an epoxy surfboard vs a PU surfboard.

A PU surfboard has more flex but is easier to ding. An epoxy board has resin that is up to 35% stronger than resin used on a fiberglass board. It can also snap back into shape better than a PU board, which tends to form cracks and delamination lines when put under stress.

Epoxy boards are so much lighter, so they are excellent for high-performance surfers. They also have more float irrespective of volume and tend to fly over flat sections of waves. They are great small wave boards.

Functionality of the two

Having said that, PU surfboards sit lower in the water, with a lesser density. Many surfers prefer this and prefer to sink a rail as opposed to feeling disengaged with the water. On the other hand, not many people have the option to have many boards for all conditions. Competent older school surfers definitely prefer to turn off a rail and feel connected to the water and the wave. They also don’t need to surf when the waves are lacking, which suits epoxy.

Differences of the two

One of the most significant differences between Epoxy foam and the PU blanks is that the PU has a different density, while the epoxy is consistent. In layman’s terms, the deeper you get into a PU blank, the less dense the foam is. Take away too much foam off the top, and you run the risk of producing a board with a soft deck, easily damaged underfoot. To keep a PU board strong, you need to take away as little from the outer skin as possible. This becomes tricky when surfers are ordering boards that are only 2 inches thick.

The epoxy blank, however, has a consistent density throughout. Therefore the epoxy boards tend to be stronger as well, with constant density throughout.

There are many other variables in the mix, however. Surfers are different, waves are different, and the majority of boards are different. Ideas and theories are just that, ideas and theories. It depends a lot on what you like, how you feel about your surfing and what sort of waves you prefer. In surfing, you do have the freedom of choice.

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