What Are Surfboard Blanks?

Surfboard blanks are the pieces of foam that are cut, shaped and designed into specific surfboard shapes. These pieces of shaped foam will become the center or foam core of surfboards, after going through the final lamination stages of the surfboard shaping process.

Shapers veiw a surfboard foam blank as the vital foundation of the surfboard shaping process, and without this piece of foam, there literally would be no surfboard.

It is very important that the shaper selects the right surfboard blank that is relatively close in size and shape to the desired final board.  This is because too much cutting away of the foam blank will leave the foam weakened and result in a surfboard with poor flex.

Just as there are endless possibilities in surfboard design, there are endless surfboard blanks. Lengths can range anywhere from 5’8″ right through to 12’1″. Widths are also available from 18″ to 31″.

Another important feature of a surfboard blank is the density of the foam. A surfboard being shaped for a beginner surfer would be shaped using a different foam density to say to a surfboard designed for Kelly Slater or tow in surfing.

The sort of surfboard shape and outline you are after will have an effect on the foam density of the surfboard blank you choose as well. For example a malibu requires a different foam density to a short board.

Don’t get too overwhelmed by all this information. Unless you are thinking of becoming a professional surfboard shaper you really just need to know that there are many designs, sizes, weights, and densities of blanks.

If you are an amateur shaper reputable surfboard blank merchants will be more than happy to advise you as to the right foam blanks for your specific shaping needs.

The Different Types Of Surfboard Blanks

Now I just will quickly mention the various types of surfboard foam that surf blanks are made from as I have already outlined the advantages and disadvantage of these types of surfboard foam in great detail.

There are 3 major types of surf blanks.  You can choose from a polyurethane surfboard blank or from 2 types of epoxy blanks, those made of expanded polystrene foam and those made of extruded polystyrene foam.

Traditional Polyurethane Surfboard Blanks

Once surfboards started featuring foam centres, in the 1960′s, polyurethane foam was the most popular selection. This type of foam is still regarded as the traditional choice. Polyurethane foam blanks are used in conjunction with polyester resins to produce what is known as a polyester, or PU surfboard.

However, in 2005 the Clark Foam factory shut down. This was the major provider of PU surfboard blanks in the US and for many other parts of the world. The end result was a shortage of polyurethane surfboard foam blanks which left foam manufacturer’s scrabbling to set up factories, and surfboard shapers seeking other more easily accessible foams.

After the surprise closure of Clark Foam, Kim Thress and Jeff Holtby, along with several other fellow ex-employees from Clark Foam, set up US Blanks, which is now one of the major polyurethane surf blank suppliers in the US.

Expanded Polystyrene Surfboard Blanks

Expanded Polystyrene (EPS) foam is also known as beaded foam and features an open cell core. Surfboard foam blanks made of expanded polystyrene foam have become the major replacement surfboard blanks over polyurethane since the closure of Clark Foam.

EPS foam blanks are one of the 2 types of surfboard foams that are used as the core for epoxy surfboards.

A very important difference between a polyurethane and polystyrene blank is that traditional polyester resins cannot be used with a polystyrene blank during the shaping process.  This would cause the polystrene foam to dissolve.

A disadvantage of shaping a surfboard with an EPS foam blank is that this type of foam will absorb water very quickly, and is not totally resistant to compression and other damage.

However, generally this isn’t that much of an issue, as the epoxy resin covering this type of surfboard foam offers a great deal of protection due to its hardness.

EPS foam blanks are the least expensive of all the foam blanks with Marko blanks considered to be the best polystyrene foam blanks around by many shapers.

Extruded Polysytrene Surfboard Blanks

Extruded polystyrene foam is the other type of polystyrene foam that epoxy blanks are made of.

The major advantage of this type of polysytrene surfboard blank is that it has a closed cell structure.  This makes is totally water repellent. So if you do damage that extra hard epoxy surfboard covering there is absolutely no need to leave the water.

In addition to that impressive fact, extruded polystyrene foam is exceptionally strong, and isn’t damaged as easily as EPS foam by compressions.

Because extruded foam blanks are water resistant, surfboards shaped from these will maintain their nice white colour, and will not discolour over the years.

Extruded foam surfboard blanks will therefore result in a faster and higher performance epoxy surfboard.

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