On Jul 1, 4:35*pm, HK wrote:
Frogwatch wrote:
On Jul 1, 3:56 pm, Wayne.B wrote:
On Wed, 01 Jul 2009 14:01:08 -0500, Vic Smith

wrote:
Some weight examples, and my view that FRP is still pretty heavy and a
new material is in order.
Solid FRP is twice as heavy as wood with less strength and stiffness.
FRPs claim to fame is durability not light weight.

State of the art light weight construction is being done with
uni-directional carbon fibers oriented in the direction of maximum
loading; vacuum bagging to remove excess epoxy resin; light weight
high strength core materials like closed cell foam, end grain balsa,
aluminum honeycomb, etc; all baked in an autoclave at exactly the
right temperature for maximum strength. *Rigid process control is
critical for maximum strength and predictable outcome. * Welded
aluminum is easy by comparison.

Carbon fiber masts when hit by lightning tend to explode into a hairy
mass due to the conducting nature of the fibers and the poor
conductivity (high resistence) of the epoxy they are embedded in.
Wood by comparison is a poor conductor. *A solid Al mast is a good
conductor with little resistance. *The same might be true of a carbon
fiber hull......

I ask you again...why are so many sailboat masts made of c.f. these days?- Hide quoted text -

- Show quoted text -

The alleged mechanical engineer doesn't know the answer to this? It's
simple strength to weight ratio.