I installed a couple of Go Power Flexible Solar panels on my Berk, which has a painted fibreglass roof. I contacted the manufacturer about recommendations of how to bond the flexible panels to the roof. The problem is that they are a very hard and slippery plastic – more or less a stiff polyethylene. Such plastic is very hard to glue, so I wanted their recommendation. They recommended either Scotch Very High Bond tape or Sikaflex construction caulk. And, if I used the VHB tape, they recommended that I seal the edges with Sikaflex. So, I found Sikaflex in the building materials section of my local Home Depot in Calgary. They have three colours: white, grey and dark bronze.
It cures with a shiney, paintable surface and sucks itself to the surface, if you have cleaned it – I wiped it with alcohol. I'm happy with the way it works after one summer of use. I used it to seal a lot of other items on my roof, such as screw holes and holes for wires to go through my roof. It looks a lot better than Dicor. Year old Dicor looks like it is ready to start cracking, I find, although it does seal for a long time.
BTW, I also used 3M VHB tape for the panels (wearing a belt and suspenders). I got a long roll at a shop that makes plastic signs for outdoor use.