Good analysis Andy. Your assumption is correct. The double layer samples were arranged parallel.

Based on the amount of deformation, I doubt that reorienting fibers of the 3.25 oz. cloth would bring it anywhere near to the toughness of the 6 0z. s-2 sample. The difference is just too great. The 3.75 s-2 sample might be improved enough to compare favorably, but then you would have something that weighes 50% more and and ends being more expensive due to the two layers. If I do more samples, I will give it a try. It would be nice to know.

Thanks,
Ted

: I presume that the samples with two layers of cloth were layed-up
: with the yarns parallel ? Do you think there would be any benefit
: in having the yarns at 45 degrees to each other ? That might be
: difficult to achieve on a boat, depending on the width of the cloth,
: but having the length of the cloth aligned 22.5 degrees to the boat
: centre line, one layer having that angle to the left, the other to
: the right might achieve a more uniformly strong composite, even if
: it wasn't actually any stronger in its strongest direction. Want to
: do more tests, or is the single layer 6 oz s-2 glass so much superior
: that it isn't worth knowing about anything else ?

: Andy