The faster surfboard: Skin friction and the 'contact angle' of the surfboard surface
It is well known that the molecular structure of the watercraft's surface can have a dramatic effect on skin friction.Surfboard designers and builders have not often taken advantage of this fact except in the use of temporary surface coatings.What I am suggesting is that the surface of the surfboard ( the resin and glass) has a measurable contact angle which is not particularly beneficial in the drag stakes... this can be improved either by adding a surface coating or by adding other substances to the resin. We have had good results with a graphite resin additive in the past, the board with graphite coating needs to be electrically charged by hand polishing ( no wax!) in order to improve the contact angle.http://www.ramehart.com/goniometers/contactangle.htmThe contact angle and water sheeting properties of some surfaces are not always fixed, for example there is a titanium coating in use which is activated by uv light to improve its sheeting properties, this process is temporary (or semi permanent ) and needs to be repeated Or to put it bluntly:It is possible to make the surfboard surface itself out of a material which is lower in drag than resin due to a molecular structure which ATTRACTS WATER There are contact angle measurement devices for sale out there I would love to get one to test various resin additives, the beauty of it is that a lower contact angle means lower drag guaranteed so there's no speculation involved . . . if one has the measuring gadget.http://www.ramehart.com/goniometers/contactangle.htmHere's a board with a graphite coated bottom and fin, it was very fast