Hard Top Build (Gluing foam to aluminum)

Hey. Bill. Could you give us sketch of what you mean? I'm not sure I am following you. I'm particularly interested in "The back edge of the top will come off, and be bolted and glued to, the existing arch. (I’ll post a picture tomorrow.) I was thinking that I could add tappered box beams along the sides of the top that the frame would be tied into and then they would tie into the arch and help add more rigidity to the top and help with the distance that we would like to span with a cantilever."

 

How about making a single skin, add glass framing (beams) under it, at the sides and transverse. Then screw a skin to the underside to make it pretty. You can make attachment rings for the speakers (and anything that has to stay put) and glass them to the top skin.

Just my 2 cents.
Lurvio