Benn there- done that. The blue stuff will compress so consider starting
out thicker than needed. I would use two layers on the bottom, and then one
layer cut out with a large hole in t he middle for a bit of stability.
The blue foam has a skin on it that should be removed. 80 grit sandpaper
will help here. Stroke in one direction only.
As far as glues/cements; I got pretty good results with silicon sealer.
Sand down the resin on the kevlar a bit, use the silicon sealer ( clear) and
weight it all down with a sand bag. Enjoy. An alternate glue could be
Gorilla glue for woodworking, and it is waterproof.