Hi Ron;

You only stretched out the weave - You can't really stretch the fibers, they're glass and they would break before they stretch (hard to do!) - So it must be something else.

Was this bias cloth over a previous glass layup or was it on raw wood? If it was over raw wood such as would be the case with a S&G, it could be a combination of insufficient wetout, where the wood sucked up the epoxy and left the cloth too dry, and wood outgassing which would produce bubbles of air in the remaining resin. I never saw any such problems when applying tape over previously glassed sections.

Sounds like sanding it off and trying again with more resin and falling instead of rising temps may be the best solution.

Good Luck, Spidey