and have a complex process for manufacture. Sometimes

All About Fiberglass Surfboards

The fiberglass surfboard that you know and love uses polyurethane foam. It is either shaped by hand or with the use of a CNC machine with the usage of a foam core of polyurethane. Over the foam core, a weighted fiberglass is laid down and then there is a polyester resin laminate that is used. After all of that, the board is sanded to a perfect smoothness and then it is cured. These boards have been around and in use since the 1960's. With their wonderful performance and extreme flexibility, these boards are sure to stick around for a while.
Another type of foam that is used for making surfboards is expanded polystyrene foam, and it keeps its shape using an open cell that takes in water like a sponge does if exposed to water. They have certain limitations, like low resistance to compression, poor strength, and it is hard to shape since it is made with small round particles. Epoxy resin is used to laminate this type of foam.
For those who want a fiberglass surfboard that is better at repelling water and great with compression, the core foam of extruded polystyrene is what you want. The board has a lot better response when it is under a lot of compression because of the great flex patterns it has. This type of core foam is what is now being used to make a lot of the high end surf boards. For the lamination, an Epoxy resin is used.
There are various grades of fiberglass matt's used and the weight is determined in ounces. If you want a strong board, you will want a cloth weight that is on the high side. Of course, this makes for heavier boards but that is not because of the weight of the cloth itself. It is because there is a need for much more resin in order to properly bond the board and the fiberglass matt. Generally, this fiberglass surfboard will have many layers on the deck with only a single layer on the bottom. This is because the knees, elbows and the feet of the surfer will be on the deck so more protection is needed.
Some fiberglass surfboard builders have attempted to build boards using a Styrofoam core instead of polyurethane, and use an epoxy resin instead of polyester. This makes the board have a much lighter weight, better impact resistance, and stronger construction. The use of epoxy resin also makes less toxic fumes as well. The bad things about making these types of boards are that they take a long time to make, cost much more than traditional boards, and have a complex process for manufacture. Sometimes, graphite cloth is used instead of fiberglass. However, this costs even more and can only be made in the color black.
There are new techniques that are being used in order to sand and shape a board in as littler as 25 minutes. This is much faster than the many hours usually required when a fiberglass surfboard is hand shaped. Of course, there are drawbacks to this. The machinery is expensive and each time a new design is used, the machine must be reprogrammed. Some have tried used a surfboard that is premade for the pattern and then they go and make the shell and then fill it with the foam. This takes about four and a half hours to complete the entire thing.