A new hollow structure

We have developed a new hollow structure that consists of laterally isolated air chambers. Each chamber is separated from the next by a thin wooden wall that is semi-permeable to air and impermeable to water.

A common issue with traditional hollow wooden surfboards is that flooding can occur throughout the entire board. This new structure prevents this. If in an unlikely event, the strong outer shell is pierced, only a single compartment will flood that can then be quickly dried and easily repaired.

Having lateral supports or trusses is also advantageous as it increases the flexural modulus of the structure compared to those with longitudinal stringers.

A depiction of the hollow structure used in Sine Surfboards. Made out of Paulownia as an eco and sustainable product.

A new manufacturing method

With our computer simulated methodologies we are able to create boards with precise material thicknesses on the rails, trusses and top and bottom skins. This is achieved with cnc machining technology. Through trial and error and the use of Finite Element Analysis (FEA) we have identified optimal thicknesses and chamber sizes to create some of the lightest hollow wooden surfboards on the planet without compromising strength.

A new nano-coating

Foam surfboards generate their stregth entirely from fiberglass. The combined weight of the fiberglass and the resin is substantial as it requires a base coat, cloth coat (one or multiple) and a hot coat or finish coat. For a shortboard, this amounts to about 2.3 kg of weight for the laminating process alone. Now is where things get tricky...

As an example, the hollow Paulownia blanks for our Fishy model are about 2.9 kg so if we glassed this board using traditional methods, the final product would be around 5 kg which is far too heavy for a shortboard. So how do we keep our boards so light?

With my knowledge in nanotechnology and through consultations with several academics we have trialed and tested a new composite coating that combines nanosilica with a 26% bio-based epoxy. This composite has greater strength than epoxy alone and allows us to use less than one third the amount of resin, keeping our boards light.

A bio-epoxy resin nanosilica composite coating being applied to Sine Surfboards natural Paulownia hollow timber blank.