Tom- I recently rebedded a lexan plastic lid in a hatch cover. I used silicone, but there was no compatibility issue because I removed all the soft, pliable, rubber bedding compound that was the original.
Could well be that the auto and perhaps the marine industry have switched over to silicone adhesives/bedding compounds for glass.
I'd try the silicone on a small area to see how it reacts and adheres to the original compound when using it for a repair.
I doubt there[s much difference between household, auto, and marine intended silicone products except for the price. Yes, there are different types of silicone sealers, etc., but those black ones with "marine"on their tubes are probably just more expensive than the auto variety.
I learned to watch this phenomena from 3M (Minesota Mining and Manufacturing).
Masking tape can be sold as masking tape, freezer tape, drafting tape (obsolete now), or a number of other products. They differ widely in the price, but you can't tell one from the other if you don't look at the label. There are hundreds of examples of this, and not just from 3M.
Do any of you know if the story is true that 3M was founded by three guys in the Minesota State Penetentiary who decided they had to get a legitimate business agle going so they could stay out of prison?
(B~C should know about such matters.)
Legitimate Joe.