And unlike fiberglass, snap means really snap, jagged edges and all. Dale Solomonson told me about making a “guitar pick” paipo our of carbon fiber for the stiff flex. It snapped and the jagged edge nearly gutted him so he said he would never use carbon again except for strategic stiffeners
In the world of advanced composite structures; when we talk about failure modes, there are two extremes:
Aramids (and similar materials) are known for a ductile, almost metal-like failure mode. That is, they will bend and deform significantly before failure.
Carbon is at the other end, with a failure mode described as explosive. I kid you not, that is the term that’s used.
Do whatever fits. But I’m still waiting to see a “Potato Chip” with Vector Net or Carbon Tape at the rails snap. I never see them coming thru my shop or people I know in the OC doing ding repair Snapped.
…any carbon laid vertical is a flex killer…a total rigid stiffener with almost no memory whatsoever…a full carbon rail wrap has a high degree of vertical orientation at the rail apex…it will break , long before it bends.
All high-end racing sailboats use carbon spars. I know for an absolute fact some of them flex like a crazy, have seen it in person. Not to say that they have a memory (or desire to snap back into position).
I think there is a lot that could be done with directional materials. A lot of people go by hearsay (not anyone in particular), there is some real science that could answer these questions, or experimentation…
Very interesting, I know that the longboard skate decks I used to make that had carbon in them still flexed as well. Maybe it’s not as rigid as we thought.
high end sail boats use carbon masts and spars for 2 specific reasons…they are both lighter , and stiffer than aluminium…the tapered ones have a very small window , where stress borders on brakeage …they are extremely high tech in the manufacturing process compared to hand lay-up…Ive always regarded using a larger amount of carbon fibre in surfboards as overkill…it has far more strength than is required…but it does flex extremely well in the horizontal plane…the verticle has more of a tendancy to twist , rather than flex evenly over it’s length.
I don’t use carbon fibre in my boards generally…but I did get quite interested when they first started talking about the nano-tube carbon…any one have any info on where that stuff is at now ?..seems to have gone off the boil.
Composite stiffness dépend of direction off stress/direction off reinforcement fiber, and off resin modulus. Carbon by itself is a very stiff material that don’t like to stretch, that’s way it’s brittle, but it have an high fatigue résistance. Well use it can make strong light durable parts…