Re: Cleat Removal
imho, it's one of two things.
1. the screws were just threaded into the fiberglass and the female glass screw threads have striped. thus when ya turn the screw, it just stays there and the male screw theads have nothing to interact with. have ya tried pulling up on the cleat while turning the screw? that's about the best i can answer as a way to find out it it's only into the glass. it'll start coming loose if this method of attachment is used.
or
there is a backing plate with a nut on it. you'll have no choice but to access the nut so you can hold it while turning the screw. how you have to access it... any way you can to including cutting a hole in the boat.
edit. suppose ya could drill the screw head off to get the cleat off, but then your gonna have a stud left and you'll still need to get to the back side of it to replace/repair it. probably a last ditch effort if ya get to that idea..