+x Chris Rogers - 9/28/2020 2:01:44 PMI third antonkov and Hanaldo's larger nozzle suggestion - 2.5mm maybe. Sometimes you can thin gelcoat with styrene to get it to flow better through a spray gun but it's also asking for trouble. Are you spraying in one shot or multiple coats with time between? Do you gauge thickness? My understanding is that most alligatoring like this is caused by trapped styrene that comes from spraying too quickly over a just-gelled first coat. The rule of thumb I was taught it to wait until no gelcoat color comes off on your (gloved) finger when you lightly touch the surface before adding more - more gelcoat or a skincoat or laminate. I've certainly had it happen when this wasn't an issue and there are many contributing factors. Good luck and let us know if you have better luck after making some changes!