That's supposedly the thing that made System Three (and West) the stuff to
use; i.e. the match between the wood and the cured epoxy. The hardware
store 1:1 epoxies are like glass.

Roger

http://home.insightbb.com/~derbyrm

"Matt Colie" wrote in message
...
CW,

snip
A great deal of the driver was a series of failures of older spars because
the Weldwood FR that everyone had been using was too brittle in when
cured. Even the joints done with cotton layer (strips of old bed sheet
saturated and laid in the joint to both make it more flexible and control
the glue thickness) were still prone to this failure. The hardness of the
FR makes it shear way from the lamination base during high flexural loads.

Epoxy is not epoxy is not epoxy. My father worked with a forgotten
supplier to get a material that was good for laminating, effectively
staturated and had a Me (modulus of elasticity) very much like stika
spruce.