On Thursday, 7 January 2021 at 23:19:11 UTC, MMOORE wrote:
The new SiO2 spray on/buff off waxes for cars are amazing. Anyone use this on glass sailplanes ?
It is a silica

SiO2 is silica, the main ingredient of sand and also of quartz.
"Silicones" names a class of substances containing the element Silicon (amongst others), which are commonly used as polishes. They are sometimes a component of "Ceramic Wax".

I am no expert on composite repairs, but the conjunction of "fibreglass" or "gel-coat" with "silicone" rings alarm bells for me!
J.