[freebeard]

I was researching for this obscure little 4-post thread and found this:

Adhesion & Cohesion - adhesives.org
[Search domain http://www.adhesives.org/adhesives-s...sion-cohesion] https://www.adhesives.org/adhesives-...esion-cohesion
Chemical bonds, however, only form for very few substrate/adhesive combinations, e.g. between silicone and glass, polyurethane and glass, and epoxy resin and aluminum. For some of these bonded joints it has been demonstrated that chemical bonds account for up to 50% of all the interactions.

So maybe a mechanical bond between the polystyrene and an aluminum edge and then a chemical bond between the aluminum and fiberglass?

It could be as easy as doubled-over aluminum tape edging.