I agree with Ty. Sand down what is on the ship, clean off the surface with degreaser then it you are spraying from your own gun thin out the primer 10 to 15% more then you did before. Check the pressure, to high or if you spray to close to the surface can cause problems. Do a test on a piece of aluminum foil (Windy trick). Also check the humidity should be below 70% for most air dry material. Let us know how you do.
Best, DennisT