Surfboard Shaping, Construction Materials and Terminology Guide

Polyurethane SurfboardsAlso known as PU (polyurethane) or associated with the Clark Foam Era. A blank is the very core of your surf board and the term “close tolerance” refers the how the close the surfboard mold is to the actual shape. Clark held a virtual monopoly on this surfboard blank market until his closure in December 2005. Now the polyurethane surfboard blanks are produced by several companies each with its own close tolerance molds. Our entire catalog of Isle Surfboards are constructed from polyurethane surf boards.

Surfboard Blanks: Polyester based urethane surfboard foam blanks are shaped to close tolerance for various designs. Since the Clark Foam closure, EPS surfboard blanks used with epoxy resin have come on the scene.

Fiberglass Cloth: Glass fibers that are woven into a cloth with weights of 4oz and 6oz, 10oz, etc.. This particular weight refers to 1 square yard of cloth. The heavier the weight the stronger the fibers.

Polyster Resin and Catalyst: Many types of resins can be used in the production of a polyester surfboard. In order to get the polyester resin to harden it is mixed with a specific amount of catalyst. Varying the amount of catalyst will cause the resin to set faster or slower in the surfboard. Changes in air temperature can cause the resin to harden faster or slower and the catalyst quantity muster be adjusted.

A word about Epoxy Resin and Epoxy Surfboards

In the wake of the Clark foam shutdown surfboard shapers of the world have turned to Expanded Polystyrene foam as an alternative method of surfboard production. EPS surfboard foam is used with Epoxy resin , as the styrene present in standard polyester resin will dissolve the EPS foam. The EPS foam has a large cell structure which makes it harder for a shaper to maintain fine details into a blank. In addition the blanks are extremely lightweight thus making it appropriate for the surfboard blanks to be weighted down during shaping. Since the blanks are so lightweight the amount of resin and weight in the outer skin can be increased thus making the boards very strong and lightweight. However another form of Foam has been developed termed Extruded Polystyrene Foam. It has higher strength, greater resistance to water and a closed cell structure. Our line of XPS surfboards utilizes this new foam and is the cutting edge epoxy surfboards available in today’s market.

As of now the surfing world is mostly committed to traditional polyurethane blanks. The alternative technologies are advancing rapidly yet still remain a pace behind in popularity. Only the future will tell us what will soon dominate the marketplace for surfboards….

Introduction to surfboard design

Surfboard Template: The outline of a surfboard. The template is the outside line that encompasses the surfboards entire dimensions as illustrated in the image above. Rounder more curved template perform rounder, tighter turns while longer straighter curves result in a template that performs longer more drawn out turns.

Surfboard Length: This is the measurement from the tip of the nose to the end of the tail. Longer boards provides more floatation, paddle with ease, and catch waves early. The larger foam volume helps them drive in slower mushy sections of the wave. Shorter surfboards turn much easier and fit into the tight arc of smaller waves. The shortboard surfboards are much more sensitive to weight transfer and critical maneuvers.

Surfboard Width: This is the widest point on the surfboard template and is most commonly between 18” and 24” inches in length depending on the type of surfboard in question. The wider the surfboard the more foam it container which enhances floatation. Narrow boards are more suited to fast hollow waves where there is lots of wave energy.

Surfboard Nose Width: Measure 12” from the tip of the nose toward the tail. Wider noses paddle easier and catch waves easier. The additional planning area is an advantage is small surf. Narrow noses enhance maneuverability especially in larger surf.

Surfboard Tail Width: The wider tail will feel a lot more loose and maneuverable at low speeds than the narrow tail. The narrow tail is used on surfboards for big fast and hollow surf where there is lots of wave energy and control in the main objective. The minimal area of the narrow tail makes it easier to turn at higher speeds.

Surfboard Thickness: Surfboard thickness in one of the most important aspects of surfboard design and how your board will perform in a variety on conditions. Obviously for the beginner the thicker the better for added floatation. But for more advanced surfers thickness can change in countless different ways along the surfboard template each affecting the surfboards performance in different ways.

Surfboard rails: This is the all important outside edge of your surfboards. Fuller rails carry more foam. This helps provide floatation when leaned on edge. Thinner tapered rails carry less foam making them easier to sink and lean on edge. Now the harder the rails edge the cleaner the water breaks away from the board which contributes to speed and looseness. Hard rails penetrate the water poorly at high speeds and resist be leaned on edge while softer rails provide a smoother more forgiving response.

Surfboard Rocker

Rocker is the curve of you surfboard from nose to tail. It can be broken down into different sections such as nose rocker, tail rocker, and center. It is the single most important aspect of your surfboard.

Surfboard Nose rocker: Nose rocker is the upward curve of the rocker in the front section of the board. It helps keep the board from pearling and is steeper in larger surfboards. Insufficient nose rocker will cause the board to pearl while excessive nose rocker will push water and slow down the board.

Surfboard tail Rocker: Tail rocker is the upward curve of the rocker near the back tail section of the surfboards . Increased tail rocker will add maneuverability and lift to the tail at speed and provide tail sensitively in critical turns

Surfboard Foil: Foil is the distribution of foam from nose to tail on a surfboard. Obviously for the board to flow correctly it must be evenly balanced thru the shape. If there is excessive foam left in the nose center or tail or dips and bumps it will create uneven flow and cause the surfboard to be unbalanced. Proper even distribution of this foam will tremendously effect it performance and flow thru the water.

Surfboard Bottom Contours

Flat: This provides a completely flat planning surface on the bottom of your surfboard. They are quick and loose in small and mushy surf but at higher speeds can difficult to turn and shift to the side when turned hard.

Concave: This provides a concave planning surface on the bottom of the surfboard. The main purpose of the concave is to channel the water flow down the length of the surfboard. This channeling of the water thru the center and squeezed out the tail add more list and responsiveness to the surfboard. Concaves are a very important design feature and can cause a board to track swiftly and improve tail responsiveness for critical turns.

Channels: The channel surfboard bottom consists of flat planes that are designed in a concave configuration. They typically number from 4 to 8 channels and direct water flow down the length of the channel. Since the channels sit side by side to each other the water is not being compressed as it is in a full concave. These concave configurations of each channel propel water down the back underbelly of the surfboard and convert this into forward thrust. Longer and deeper channels give a more pronounced effect.

Vee: This is the opposite off concave. Vee is used to loosen up the tail at high speeds and increases the rocker at the rail line which makes boards turn more easily. Overall Vee makes a surfboard easier to lean on edge.

Surfboard tail designs

Many tail designs have come and gone over the years. We feel a few more notable designs should be mentioned here.

Rounded Pin: Rounded Pin Tails are very versatile and smooth rail to rail. They hold the surfboard in the after and transition from rail to rail well.

Pin: Primarily for larger waves. These tails have the minimum amount of area and hold in well at higher speeds in big surf.

Round Tail: A very smooth turning tail that has a bit more area than the rounded pin tail. The extra area makes it more suitable to smaller to mid range surf.

Square Tail: The square tail contains the greatest area of any tail design. The square tail design will carve the sharpest most pivotal turns and be most responsive.

Squash Tail: Just a rounded version of the square tail. It is somewhat less responsive and its carves are not quite as sharp and pivotal due to its rounded corners.

Swallow Tail: The swallow tail is basically two pin tails side by side. The swallow tail shifter to the other rail there is a hesitation from one side of the tail to the other. The gap allows water to flow freely between the two pins and hold well when banked hard for maximum water flow.

Surfboard Fin Setups

Single Fin: The single fin is where the surfing fins started. It was first put into use based on the keels on sailboard to stabilize the surfboard. Its increased size is due to the use of only one fin. Since the fin is located in the center is tends to tighten up the board thru turns however it will hold well in the large surf.

Twin Fin: The twinzer is a design popularized with the fish type surfboards. The twin fin set up tends to loosen up the tail of the surfboard and allows it to remain stuck in a straight line and then turn quite loosely. Once you get a feel for the twin you can really drive down the line and carve thru turns easily.

Thruster or Tri-Fin: The thruster is the staple of fin set ups in surfboard production. It was invented by Australian Simon Anderson in the early 80s. The thruster simply added a stabilizing center fin to the twin fin set up and suddenly the surfing became much smoother thru the turns and transitions. And the idea has stuck to the present and is widely recognized as the standard fin set up for most stock shortboards.

Quad: The quad is an attempt to correct the looseness of the twin fin while maintaining the speed and drive. The design is becoming increasingly popular with big wave riders and even some shortboarders. The extra set of twin side fins really adds speed and drive and helps stabilize the surfboard in the absence of the center fin and its associated drag.

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