All i do is just keep spraying over the old paint, my bike probably has about 50 coats on now including a powder coat with in it somewhere. I just get some rough sand paper and rough the paint up a bit, get a better primer than what the paint says, (eg one of its colours was red, it said to get a grey, but get a white, better outcome.) And then just use about 5 coats of primer with 20 minute gaps. then spray your desired colour on, don't be a fool and let it drip, its just about taking your time . then use about 1+1/2 - 2 cans doing this, then laqure a very fine coat, leave overnight, and then give about 10 coats of laqure. Sorted. Look at my dp, i did this myself.