Michael Dresdner: It could be any number of things, including too much air pressure, a poor air-to-fluid ratio, the wrong-size fluid tip, or simply applying too much finish at once. Try adjusting your air pressure and airflow, reducing the volume you spray and dropping down to a smaller tip size, all of which can help. Most water-based coatings do better with a l-mm fluid tip, while most guns set up for spraying lacquer come equipped with a tip almost twice that size. You might also try some other brands of finish, since some spray better than others. Finally, you can eliminate foaming bubbles, those that stick around annoyingly and refuse to pop, by stirring in about 1 oz. of half and half per quart of finish prior to spraying.