Al and other Swift builders,
Thanks for the information. I've been a little concerned about the hybrid
as it has become a bit more scarce. It seems that all of the high tech
materials are in high demand and are seeing some price increases.
We've been aware of the slight difference in the Kevlar used in hybrid,
however, it is important to consider our application. We would use carbon
alone
if we were strictly looking at strength. Instead, we use the Kevlar because
of it's ability to withstand the loads placed on the hull and deck where the
bulkheads intersect. After doing some careful autopsies on boats from other
classes, we reached the conclusion that a big part of the failure (loss of
ability to hold rig tension) of boats in many classes is the result of
compression at these intersections and the failure of the core and the fabric
in
those areas. Kevlar, unlike carbon, has the ability to disperse that kind of
side loading far away from the intersection, protecting both the integrity of
the skin and the core. The small difference in the Kevlar becomes
insignificant since the carbon is carrying the tension loads anyway. Some of
us have
made the mistake of using all carbon in our blades only to find that they
shear
off at the hull or cassette bottom. We've learned that we must replace the
first couple of layers of carbon with hybrid to remedy this problem.
Thanks again Al for the opportunity to address this subject with all of our
builders.
Best regards,
Bram
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