Bob Crantz wrote:
That light coming through depends on the woven material. Fibreglass matt is
usually white, so it reflects all light.

That's the wax holding it together.

.... The reason light gets through is
because the weave has gaps in it. The reason there are gaps is that the
glass isn't laid up properly, it is stretched beyond specification.


Maybe, maybe not. The ratings on fiberglass cloth tell how
long the component strands are.... longer is better of
course... cheap cloth or roving, such as used for auto-body
repairs, will be made up of a lot of short strands spun into
yarn to make up the weave, but it's not as strong as the
same weight of cloth with more continuous strand.

Very interesting stuff, I'm learning.

DSK