Hi
Have removed all antifouling with scraper and sanded hull with 120 grade to remove the residue. There are a few scratches/nicks in gel coat. Has anyone used top coat rather that gel coat filler as not sure how thick original gel coat is. There are a few chips where the laminate looks visible so don't want the deepen further. Could I apply topcoat layers and sand lightly between to remove wax? I would then sand and prime/antifoul. This would only be isolated areas....,never used topcoat so will this work. Other option is deepen slightly and gelcoat filler....all advise appreciated
Why not use Gelcoat (flowcoat really)? You don't really need to deepen the scratches for that, just cleaning them up is enough, although a fine Dremel bit to make it a little wider if it's a very narrow scratch might help. Definitely do degrease with acetone and then brush on some.
But also keep in mind it's the bottom and doesn't have to be perfect. And since it will be painted over anyways, you can also use (thickened) epoxy, which will definitely never fall off.