is that a single stage or BC/CC? I mix my SS 1 part reducer 1/2 part hardener to 8 parts paint.
30 -40 psi should be good for bs/cc . if you are mixing 1 part hardener to 4 parts clear, you could try adding 1/2 part medium reducer to thin it out some and get a wetter flow. it also may be you are moving to fast. it is a fine line between going to slow and causing runs. do you have any flat panels you can practice on? I always spray something flat to get my gun dialed in and air pressure right before I put it on the car. I am not a professional, this is just my experience. I like using a little reducer so the paint will lay flat before it starts to dry. also , prep is everything, I wet sand with 220 to smooth it all out and at the same time giving the paint something to grab onto. then I use a good grease remover and wipe it all down with a lint free cloth. you will get it , it just takes practice and getting your settings and technic right. this sounds crazy but I also attach a piece of chain to the body and let it hang onto the ground to elimate the possibility of static electricity that will draw dust into the paint/clear. I also wet down the floor so im not kicking up dust