I have an older in-ground fiberglass pool. The tiles at the top (6") are all coming loose and I plan on removing them and replacing them with new tiles. The old tiles appear to have been put on with a mastic that is also peeling off. Beneath the old mastic the pool surface is an extremely smooth gelcoat.
I'm curious to know how to best attach new tile. One video (Utube) suggests a silicone based adhesive and I can see the merit in that but will it stick to the surface as it is or do I need to remove the gelcoat or maybe just rough it up with a grinder?
I'd appreciate any thought from those that have had to replace tiles on fiberglass.