When I sprayed PPG Flexed and Flat Urethane on my F-22 I learned that you don't spray it on in a heavy wet coat. Keep it almost dry and put on a couple of coats in that manner. A wet coat will yield an almost gloss finish. When I say dry, I don't mean so dry that you get a rough finish. Just put on a thin dry coat that's just shy of showing a wet gloss.