Conceptual Surfboard Design.
Using a thermoformed Hexaflex matrix as the core material, it is possible to make an extremely strong, yet lightweight, surfboard. The core matrix is an open hexagonal cell based design which has the benefit of a high surface area for secure bonding of finished skins combined with the ability to be easily vented. The core matrix is a monocoque construction which allows the stresses that the board is subjected to be instantly absorbed throughout the board. This allows for a more responsive flexible board.
Vacuum Forming mold
A vacuum forming mold made of ¾” plywood approximate size of 8’-0”x 2’-6” which has a multiple array of approx 3½” hexagonal, cross sectioned plugs glued to its surface.
A mold of the bottom rocker surface is slipped over the hexagonal plugs to provide the bottom surface of the board.
The height of the wooden plugs are chosen to approximate the given curvature of the upper surface of the surfboard.
The end surfaces of the protruding hexagonal plugs are shaped and faired by hand.
A 40 thou thick (0.040”) plastic sheet (polypropylene?) is vacuum molded to form a complete surfboard blank.
The blank then has rails, stringers and outer skins attached by vacuum forming, resin infusion or standard lay-up techniques.
|Cross section of matrix panel|
|Double stringer placement.|
The Handling Characteristics.
The matrix can be tuned by selectively separating cell walls within the matrix to varying depths which will allow control of the degrees of flexure in prescribed board areas.
This concept will be applicable to double skinned composite boat hulls.
Another method of using the hexaflex matrix in the surfboard was suggested by Oneula:
"I can see vacuuming a sheet of this stuff between two 1" sheets of blue XPS on a rocker table
then cut out the outline along the standard inset perimeter rail outilne
then glue on using the same rocker table a solid rail band of either more blue dow xps or precision board or corecell
then final shape the board by hand.
with the 1" top and bottom xps sheets you can shape in bottom contours and thin out the profile as needed
as the thickness of the xps is reduced it should indice more flex in that area (tail/nose)
kind of like a reverse design of a surflight blank or a solomon-like blank with a plastic versus xps core
just an idea"
I replied with;
" "where do you get the stuff from and how thick is it?"