"Marske Flying Wings" wrote in message .. .

Spars constructed with carbon rovings are unpredictable and tests have shown
that compression and tension readings are very low ( 30.000- 60,000 psi)
whereas using a carbon rod will give a predictable 300,000 psi.

Jim Marske shows carbon rovings to have 120,000 psi tensile
strength in his website. Not the numbers you show. ??

Mat, please cite for me the instances where the carbon roving
spar caps have failed. Either during proof loading or in flight.
Windrose or Carbon Dragon.

I will not question that the pultruded carbon
rods are an excellent building material. Had the stuff been
available when Culver and Maupin were designing they may even
have used them instead. But you can't say that the carbon
rovings are dangerous (you say/imply this in your website and imply it
in your postings).