Brian

   You do not have to go so far, If using pinless floating built-up
technique (riveting the inner layers without external prepregs) you will
easily create a situation where one prepreg will not align to other in 100%.
This also can cause to the glass fibers to not be 90º to each other in the
total book.

Shabtay
Eltek - Israel

      Brian wrote:

        MoonMan

        Please allow me to add
        10) Quality of glass cloth: much of the cloth we are seeing today
has
        been woven unevenly, often with the warp and weft locally not even
at
        90° to each other. This is rolled up under stress and goes straight
into
        the treater. Result: when the prepreg is pressed and the resin
melts,
        some of the resultant strain is relieved, but is partially
dissipated in
        the adjacent layers, which also become stressed (if they aren't
        already). Just waiting for a passage above Tg for stress relief!

        Brian

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