If, like me, you do your spray painting outdoors, beware of breezes. Aside from the obvious, another problem they can cause is the one that you reported. My area always has variable winds that swirl around from random directions, so I have learned to wait for moments of calm when I paint. Early on though, I didn't always stop soon enough after the wind picked up again, and I got gritty paint coats as a result.

Another thing: apply the paint in one smooth steady stroke from end to end in one direction only, keeping the pace moderate and constant from beginning to end, and maintaining the same distance throughout. It often helps to start the spraying just ahead of the rocket and stop it after you have gone past the other end. Then rotate the rocket a quarter turn or so and repeat the process. Continue until the rocket is fully covered with an even coat. Jerking or jiggling the can around as you spray is another way to obtain a gritty coat and spattering of paint. Sudden movements cause momentary surges and ebbs in the amount of paint that is delivered to the nozzle. To lay down an even coat, you need to have a constant, even fan or cone of spray from the nozzle, and to deliver it the nozzle requires a steady flow of paint from the can.

__________________
SAM # 0011