Acrylic to Glass with Silicone??

[fkshiu]

Mixing materials is always a bit iffy. Silicone tends to stick to glass far better than to acrylic.

GE I silicone is "good", GE II is "better" while GE 1200 is the "best" if you can find it. 1200 is what aquarium manufacturers use.

I used 1200 to silicone acrylic baffles to a glass sump and it's watertight, but having to hold up against gravity and water pressure (being an outside pane as I understand your intentions) is another matter.