Rare earth magnets are the way to go...they clamp well and allow the canopy to flex preventing bubbles along the edge. I like Weld-Bond glue...dries clear and excess can be rubbed off cleanly when dry with a finger if necessary. Google Magcraft magnetic products. I use the 1/4 x 1/4 cylindrical mags and it takes about 60 pieces to do a canopy.

Mike