ITW Plexus makes over 20 different products you can check out on their website
ITW Plwxus
I got some samples and did my own unscientific tests with them and was not impressed. I would remove all old tapping screws,clean,caulk with 3M 5200,and then if you like thru bolt where possible,and as Trayder did glass the two parts together on the inside where access makes it possible. Because the 20' is a one piece cap/liner I am glassing mine on the inside at the areas I can reach,the anchor locker and rod storage etc... [img]/images/graemlins/grin.gif[/img]