I think it’s the aesthetics that will cut into the appeal for surfboard buyers. Brown boards just aren’t that appealing - except maybe to the hippies. I guess it can be bleached or dyed, but I figured I was already pushing my luck trying to bag a hemp deckpatch.
In terms of eco-power hemp linen should have a somewhat lower carbon footprint, 'cause it supposedly doesn’t require a lot of processing or chemicals to get that loose weave going. Grows fast, supposedly good for the soil, yada, yada. Of course, there’s so much hype going in the eco-trade they might as well be selling magical elixers and snake oil.
I was reading up on a form of resin infusion (VARTM) that might work well enough to infuse a fin panel in one pass. Between that and Larry Allison’s comments about using heavy fabrics to get the better fiber/resin ratios I’m wondering if maybe a hemp fin panel in epoxy might be doable without a lot of mess or waste. Then again, I’m itching to try resin infusion on aircraft ply to do fins that don’t require exterior fiberglass.
I’m operating under the theory of having way more time than common sense.
I tried a linen/cotton blend and a light weight cotton on my fiji quiver this spring. Both sucked up more epoxy than s or e cloth, but both were much harder to cut lap and sand open over fin boxes.
New resin with optical brighteners looked like shvt over the tan cloth.
Cotton swells when it´s wet. Can be use as bulker. Hemp, linen and others natural fiber have good properties by itself but very disappointed when use in long fibers in composits with organic resin. Problem come from their natural non homogenous , so they can only be use in non structural parts and often coupled with other classic fibers. That´s in industrial parts where composits are mostly design to work in tensil. But for Surfboards why not, because surfboards skin have to be strong in flexion (simple flexion and buckle flexion) where stiffness essentialy come from thickness and resin.
Hey guys thanks for the acknowledgments:) I have used a lot of Linen/flax fiber as mentioned and use it mainly for the aesthetic but im convinced it is as strong as the fiberglass counterparts of 4oz and 60oz if not more durable but Lemat will know the particular numbers.Have used it in place of the generic carbon patches on the tail area with good results… Theres an interesting link http://flaxcomposites.com/?page_id=106 id like to share for those of you interested in the stuff and it has some tech info there…In some crude tests i have found it to be more “elastic” than fiberglass so have figured that it makes a good bottom for timber teck boards. It completes the “natural” look that may be hippy or hipster or whatever labels you want without going to the lengths of stiffening the board too much with a layer of wood top and bottom…
the stuff i use comes in various colours and has a very open weave which allows good wetting out and keying together with other layers…
By itself flax en hemp can have really good mechanical properties but not consistent. So it give statistically not so good composits. But because it´s low density ans swell resin, it give at same weight than glass a thicker stiffer skin wich is stronger in flexural stress, most important for us ( simple flex=dent, comp flex=buckling)
Why not consistant ?..modern fabric manufacturing should have reliable consistancy…also , at 288gpsm , it would not swell in resin unless it was compressed somehow during manufacture ? …even more so if it was a hybrid using bamboo or silk…I’m inclined to think that bamboo or silk would greatly reduce any tendency for hemp to swell in resin ?
Better to say constant. Come from the natural growing of plant. Finally need more material to secure expected performance. That was one reason of développement of polymère fiber, constant predictible with fiability perf.
