Just a heads up, in case you didn't know: Silicone is BAD news with fiberglass. It has pretty much achieved "inside joke" status when it is mentioned, especially around Donna.
i didn't know this when I joined, just knew what a PITA it was to remove from projects around the house. It was FGRV that educated me to the evils of the stuff.
If you already knew this, I apologize for stating the obvious.