For the full article, see Surfboard foam.
The other day I walked into a surf shop and saw a board that looked just like a traditional Polyurethane fiberglass surfboard. It was the usual off white color, with a center balsa stringer coated in fiberglass resin. The sales guy says "that board is a sweet epoxy board." I scratched my head because when I hear epoxy, I think of Surftech's Tuflite boards. You know the boards that look like they’re coated in a hard plastic shell with no stringer. So I decided to do some investigating. See full article at Surfboard foam.
The main choice of surfboard foam these days are Polyurethane (PU), Polystyrene (PS) or Expanded Polystyrene (EPS) foam. Polyurethane foam has been the shaper's choice since the 1950s. One of the advantages is that it is light and very shapeable. If you look at it up close, it's very fine and brittle so you can take sand paper and shave off corners without tearing into it. If you plan on buying a custom surfboard, most likely it’s made from Polyurethane. However, one of the biggest downsides is its highly toxic nature. It has potential hazards to individuals working with these materials, possible contamination to the environment and they're a non-renewable product. There was an influx of new surfboard construction and use of different composites when Clark Foam, the biggest distributor of Polyurethane foam blanks, closed their doors in 2005.
Polystyrene (PS) foam is a lighter alternative to traditional Polyurethane foam. However, it takes about two to four times the labor to shape. They're not as strong as Polyurethane but with the coating of epoxy resin, it becomes durable enough. Polyester resin (used to make fiberglass) dissolves polystyrene foam so the addition of epoxy resin is needed to prevent this. It also has the advantages of being environmentally friendly and recyclable. Like Polyurethane, you can also buy blocks of polystyrene foam and shape your own board.
Expanded Polystyrene (EPS) foam is a version of polystyrene foam. They are now gaining popularity and they’re typically found in the core of Surftech's Tuflite and Firewire surfboards. You probably already familiar with EPS foam. The light disposable coolers you can buy at the super market are EPS foam. They’re also the same foam used to safeguard products in boxes or packages. They’re made up of tiny little foam balls similar to the size of BB's and compress together with an adhesive. EPS is typically the lightest of the three foams used in surfboards. The disadvantage of using EPS foam is the difficulty of hand shaping it. If you took a sand paper to that disposable cooler, you'll know what I mean. You'll end up tearing chucks of foam out with the sand paper. If you're looking for a custom board, it will be very difficult to find a shaper who would want to work with this material. Surfboards made from EPS foam are typically molded by machines. It is possible to buy molded shaped EPS foam. This is where the term "Pop out" board comes from. Also, EPS foam is more prone to absorb water but recent developments have been able to improve those issues.
Density vs. Buoyancy
When choosing a surfboard, one important aspect of performance not to overlook is its weight. A lighter board means more buoyant and floatable. When you compare three boards, made from the three different types of foam, the lowest density or lightest board will float you the best. The advantageous of better buoyancy is great for paddling and allowing you to ride a smaller board for maneuverability. Each type of foam can have different density levels depending on how much the material has been compressed. Typically EPS is the lightest of the three and Polystyrene is lighter than Polyurethane foam. However you might also want to weigh your decision on the durability of the surfboard as well. Polyurethane surfboards are the easiest to repair. EPS foam core is less likely to deteriorate over time and companies like Surftech with their epoxy fiberglass shell tout that their boards will last longer than traditional Polyurethane fiberglass surfboards.
These two materials are traditionally used with polyurethane (PU) foam blanks. The standard shortboard PU core is covered with one layer of 4oz “E” cloth on the bottom and two layers on top. “S” cloth can also be used and will strengthen a board with no increase in weight. The fiberglass cloth is then coated with clear polyester resin.
Pros: Although more shapers are producing boards with alternative materials, it is much easier to order a custom Polyester/PU board. Professional surfers prefer this combination for their performance and flexibility. Polyester resin is cost effective and a time-tested material.
Cons: Polyester is much more susceptible to fractures and dings. Fiberglass resin and PU are not environmentally friendly materials. For these reasons the leaders of the shaping community are finding ways to combat the "disposable board" syndrome.
Myths: A PU blank is not limited to polyester resin. Epoxy works, too.
Since Clark foam shut down operations, extruded polystyrene (XPS) and expanded polystyrene (EPS) blanks have gained popularity. These materials will dissolve if polyester resin is used. Glassers must employ epoxy resin. You won't find many shapers making custom EPS or XPS boards, but it is very easy to purchase brand name models off the rack. Although epoxy resin can be used with PU, it more commonly found with EPS foam. The Epoxy/EPS combo has some advantages over traditional Polyester/PU boards.
Pros: This material is lighter, stronger and more buoyant. As a rule epoxy resin is twice as fracture resistant as polyester resin. Many riders claim these boards paddle extremely well and enable them to drop a few inches from their board length. Epoxy is also much less toxic than polyester resin. According to SurferSteve.com, some epoxy boards in the surf shops may only use epoxy resin in the laminate. Ask questions. One last benefit: If shaping with epoxy resin you will like the fact that it hardens much more gradually than polyester resin.
Cons: Epoxy resin is twice as expensive as polyester resin. Non PU boards also require more labor, resulting in a more expensive board. If using EPS then the board will absorb water more so than either PU or XPS if you experience a fracture.
Myth: To the contrary of just about anything you read, hand shaped Epoxy/EPS boards are more flexible than your current polyurethane board. The fact that epoxy is stronger than polyester makes it difficult to see that epoxy is also more elastic.
The recent acceptance of new surfboard manufacturing techniques and materials has spurned a select group of shapers to use wood as a chief ingredient to their board building recipe. The resurgence of wood boards has resulted in beautiful works of art that use wood’s characteristics to boost performance. The environmentally friendly materials and manufacturing process make these surfboards great options for surfers looking for green, high performance boards.
One such shaper to focus on the properties of wood is Danny Hess, founder of Hess Surboards. Hess is a wood working craftsman who now resides in San Francisco, California. His thoughtful approach to the resources he uses influences his view on board technology and the materials offering the best performance with the least environmental impact.
To start, each of Hess’ boards is built using Amapola, Cork and Poplar due to these materials' high tensile strength to weight ratio. This strength is applied when crafting the boards’ wooden perimeter frame. This frame and the perimeter stringer eliminate the twisting characteristic (torsion flex) found in traditional foam/center stringer surfboards. While torsion flex can cause loss of speed, Hess’ design results in a predictable amount of flex memory along the stringer and rail line, producing a transfer of energy that is very efficient and responsive. Showing a nice balance of old school and new school, Hess then inserts an EPS foam core, shapes the deck and bottom contours, and uses a wood skin to bond the perimeter frame to the EPS.
The green benefits of this manufacturing process are substantial. The boards are made from reclaimed and sustainably harvested wood, recyclable EPS foam, and cork which is a renewable resource. Epoxy resin is used because it emits very low volatile organic compounds and each board uses roughly half the fiberglass used in a traditional foam surfboard. Each Hess board has a longer lifespan because wood does not break down or lose its responsiveness like a standard PU board.. That means fewer new boards and fewer dead boards in landfills.
Hess is not alone in his desire to produce greener surfboards. A quick Google search for wooden surfboards will produce many sites for shapers who care about their environment and their customers’ surfing. The irony is that while surfers generally care a great deal about the environment, our sport is one of the greatest offenders to global pollution. Perhaps we should take a few minutes to learn about a new cleaner manufacturing technique using an old material that just may improve our surfing.
Once you and your shaper finish discussing the shape of your next board, it is a good idea to approach the subject of a sanded finish vs. gloss finish. Each have their own merits and, depending on who you’re speaking with, their faults. SurfScience outlines the facts and commonly held theories regarding these two techniques.
According to George Orbelian’s book, Essential Surfing, a sand finished is achieved by carefully using 60 D grit sandpaper over the entire surface of the surfboard, then switching to 100C sandpaper. If not careful, it is easy to cut into the fiberglass cloth layer beneath the laminating resin.
Orbelian continues to explain that a gloss finished board requires a final finish coat after the sanding. The purpose is to cover any scratches left by the 100 C sandpaper. The finishing resin dries with a semi-gloss finish. Bringing the surfboard’s surface to a high gloss finish requires wet sanding and polishing with a power buffer or by hand.
Leaving the surfboard with this sanded finish produces a lighter end product because no finish coat is added. In addition, a sand finish is less expensive to produce and, in some circles, thought to produce a faster surfboard. The downside to this process is the fact that a sanded finish is more porous, which can lead to water damage and deterioration. As a result, these surfboards are considered less durable than boards with a gloss finish. The sand finish also collects a lot of debris and particles in the water, making the surfboard difficult to clean.
Many professional surfers choose to ride sand finished boards to avoid the added weight of a gloss coat. Because pros push their equipment to extreme levels, they often move on to a new surfboard before water absorption affects performance.
A gloss finish will add weight and about $75 to a surfboard due to the coat of finishing resin and extra labor. It’s uncertain exactly how much weight is added, but it’s thought to be between one lb. and 1 ½ pounds. In exchange for the increased weight a surfer receives a better sealed board with no pin holes or sandthroughs in the resin. The seal will limit water absorption, making the board more durable while also keeping its liveliness for a longer period of time. Another great benefit is the beauty of a glossed finish; it will often produce a surfboard truly pleasing to the eyes. Finally, these boards are also very easy to clean.
As you conduct your own research on sand finished vs. gloss finished surfboards, you may ask your shaper which he recommends for the shape he is making for you. One theory suggests a sand finish is best for displacement hulls while a gloss finish is best of planing hulls. As is usually the case, this is a great topic you can use to engage your local shaper and help him produce a great surfboard to enhance your surfing.
Sanded Finish Weight: 1.5 pounds lighter Cost: $75 cheaper Speed: Many believe a sand finished board is faster while some believe it is by a very small margin, if any Durability: More porous so water damage is more likely, shortening the surfboard's life span Aesthetics: Dull look
Glossed Finish Weight: 1.5 pounds heavier, but most have difficulty feeling the difference Cost: On average the extra materials and labor will cost $75 more Speed: One theory suggests a gloss finish is best for a planing hull, which most boards have Durability: Sealing off the tiny pinholes left by sanding the board will limit water absorption and increase the lifespan Aesthetics: Very pleasing to the eye