Cork grip on windsurf booms
Updated: Dec 11, 2020
Cork grip is an excellent choice for riders who are after long hours of high engagement windsurfing with a large share of off-the-harness activity. Being firm, it complements the sense of immediacy expected from a stiff and responsive boom. With proper care - waxing - it offers unprecedented levels of comfort and efficiency of grip. Fatigue and blistering are significantly delayed in comparison to its syntetic counterparts (EVA etc). In addition, it is easy to repair and maintain.
What is cork grip
Cork grip is the outcome of covering the boom tubes with thin sheet of agglomerated natural cork. This material is used for wall coverings, under-floor insulation and the making of decorative or utility items such as yoga mats etc. The grade that is most suitable for boom grip is the one comprising of cork particles in the size range 2-6mm and is commercially available in the form of 1-1.5mm thick sheets/rolls. The cork material is glued on the boom surface with contact glue (chloroprene based). Then it is sanded smooth and treated with a special wax formulation (surf wax) to enhance its endurance and efficiency.
Cork grip delays fatigue
The most beneficial contribution of cork grip to windsurfing is that it delays the onset of forearm fatigue. It is comfortable and secure because it is firm and offers traction without irritation. What follows is an effort to describe why firmness and the adaptive nature of cork are instrumental to the efficiency of windsurfers' grip.
Efficient boom hold is governed by the level of friction between the skin and the grip material and muscle strength. It is very much like the effect of rope being wrapped around a sail winch; the muscles facilitating the mere curling of the fingers around the tube. The rest of the action is taken care by the nature of the interface between flesh and the windsurfing boom.
The skin of our palms features a textural wealth of crevices, valleys and peaks, oriented randomly in order to facilitate traction of hold in all directions. Moreover, the skin between the distal palmar crease and the root of the fingers is soft, malleable and eager to wedge itself in the interface with whatever is being held, twisted, pushed or pulled. When clenching onto something firm, the naturally designed skin micro texture and folds set anchors in and around the texture of that object. In the absence of firmness, as is the case with soft synthetic foam, the anchors drift, the hand slips, releases and then clenches again to reestablish new anchor points. Palms and fingers go into a repeated milking action of the boom tubes trying to regain grip. Then the wrists start flexing into a false grip and finally the musculature of the forearms fails. For some, this may mean more than an innocent soreness; it may lead to undesirable conditions like trigger finger or carpal tunnel syndrome.
The repeated clenching to failure does not happen with firm substrates such as cork grip. Fingers and palms stay where they are set at, the skin smoothly conforming to the natural texture of agglomerated cork. Traction is uniform over the entire contact area and not limited to the areas of highest compression. The faint trace of wax on the grip provides lubrication just enough for the skin to settle and spread shear to a larger area. By synthetic grips, traction may be too high of a stimulus for skin to handle and the call for relief may lead to the vicious release-clench cycle with the aforementioned outcome.
Cork strength and ease of repair
Properly maintained cork grip is far more resistant to brutal treatment than the customary soft low-density EVA grips. In addition it will not swell or delaminate in time and it does not split at the seam.
Cork is very easy to repair with minimal tools without requiring a full regrip by a specialist. A small gouge may be repaired by the boom's owner to an end effect of aesthetic appeal equal to that of the original make.