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US Blanks – Parabolic Stringers Explained

April 27, 2018 / Murray Steward

Parabolic Stringers Explained.

Traditionally, all surfboards required a stringer (stiffener) to strengthen the core of surfboards. Without a stringer, (always centrally placed down the middle of a blank), the core became too flexible and too prone to breakage. Stringers have usually been wood. The best stringers are made from knot-free milled timber chosen for strength, not brittle, usually a blond wood such as American basswood.  Australian blank manufacturers have mostly used ply stringers, which have served them well. US Blanks best selling stringer is unidirectional PLY (i.e. vertically milled, not peeled) and unidirectionally milled basswood, in a range of thickness and lengths. Basswood is renowned for its excellent knot free structure (i.e. no weak point), and springy, easy to shape nature. Stringers also come in various other woods such as Birch, Redwood, Laminated Ply, Cedar and Balsa.

 Parabolic Stringers scribe a parabolic arc along the rails of surfboards different for each length of board, and are set for pre-determined flex patterns. They are bent to form a shape that offers very different strength and flex patterns to a surfboard. Difficult to fix to the blank as the blank has first to be cut in a parabolic arc, the stringer (Basswood, balsa or even HD foam)  is bent and glued to fit. It must also follow the rocker line of the board and proscribe a consistent arc – very difficult as the rocker is usually set by the centre stringer. Only one company in the world has refined the parabolic process for custom boards – US Blanks in the USA. The difference in performance and feel is remarkable. Our employees love them.

Click on this download section for the US Blanks Parabolic Stringers explained.