"I'll do some experiments with silicone between a clear coated surface and aluminum.
Seems as though scuffing up both surfaces would be appropriate.
Has experience shown this to be unnecessary with silicone?"

Decades ago, I built a couple of aquarium fish tanks, using clear silicone sealer to hold the five panes of glass together.  When the tanks were full of water, there was considerable pressure on the joints, which held tight. I didn't scuff up the glass in any way; all I did was clean it thoroughly.

Dennis
580 hours, Legacy