I have cut my fin and reshaped, sanded it smooth.
Do i need to paint it to avoid any damage to the glassfiber laminate? I know UV radiation doesn't really mix with epoxy and glassfiber resins unless they are UV resistant but im not planning to have much airtime anyway :D
What about water?

I have trouble getting paint to stick to fins so I stopped bothering.

A few hours immersion in water every fortnight isn't going to do much. if you are concerned give it a coat of uv stabilised epoxy and sand smooth.

I've re shaped heaps of fins. and never did anything .

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