Are you brushing or spraying?
I'm brushing (signature) on the coamings, gunnels, console and cap on my 18SF that I'm rehabbing over here in Harwichport.
But I did put a coat of gelcoat on the new cover I made that fits over my new fuel tank. Its coosa/penske with a lot of layers of glass on it.
I will then brush signature and non-skid (kiwigrip) over the gelcoat (once I get the wax off and sand it out).
I used the gelcoat primarily as a sealer coat over the polyfair which is very porous. Its good to seal it up and give it a little bit of a protective shell before top coating.
If you're spraying you can get good looking coverage with gelcoat but its a little tricky to brush on and get a nice finish.
With top-coat paint you can pretty much go either way. Spraying or brushing, you'll get a pretty good result.
Signature is a two part polyurethane kinda like interlux perfection.
You could also just roll and tip on a nice coat of one part interlux brightsides. That would be cheap and easy albeit not quite as durable as the two-part, which is not quite as durable as gelcoat.
But of course as always, your mileage may vary.
