Depends on the material, wooden I would seal with car lacquer first prime ( white for colours, grey for black colour over top, red primer for under water line, seal with final cop coat of lacquer) then car paint (colour) rub down between coats, lacquer to finish buff and polish or for your tug satin finish not gloss!
Plastic hull/structures use a plastic based primer ( it etches better other wise it has a habit to just peel up) then Any car paints on top, lacquer finish, again satin.
GRP (Fiberglass) and metals any car primer + colour and satin finish. ( although metal parts you want an etching primer)
Air brush acrylics or hand... work fine but the final coats have to be durable so again car lacquers or varnishes.
Finally enamels! I put enamels last and I wouldn’t use them for anything but a brass part in today’s world, however that said if you can wait long enough between coats and give it 6months to really harden up after painting they can give astonishing finishes with wet and dry and buff and polish!
Honestly car body paints are the way to go, just ensure depending on your material which primer to use and ensure surfaces are sealed! ( don’t use sanding sealer on wood use a lacquer this is that sanding sealer dose not seal in the way you may think Lon gun term the boat will still move about giving you cracked or crazed looking finish) also do not use oil based stains unless using an oil based varnish for wood parts.
Check out our painting section on the forum for some logs and experiments people have done using a variety or paints and in my case check out the sea urchin build log in h thy e vintage section on how I used epoxy varnish to finish a boats colour job!
Anymore questions feel free to ask, we have a couple of real painting pros here who will prob tell me off in a min!
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