ide use VHB tape, its made by 3m and its tape on roids. you know the la opra house, well its siding is aluminum panils and they used 4 1"*1" squares of the stuf to hold them on, CRAZY STUFF!!!!(omg)
its bacicly the worlds strongest 2 sided tape. odk were you can find it but most likely your local hobby shop
good luck
adam