I want to respay my bumper. how should i prep it and what paint will not react with the factory paint job?

I am a professional sprayer but i know if you spray certain paints over existing paint you can get certain types of reactions that will destroy the finish. i would like to know whats compatible with what.I want to respay my bumper. how should i prep it and what paint will not react with the factory paint job?
Provided that the bumper is now original,there will be no unexpected reactions to contend with.The paint used from the factory is the same urethane catalyzed base/clear as used on the rest of the body.Some painters use a flexible 2 part primer as necessary.I want to respay my bumper. how should i prep it and what paint will not react with the factory paint job?
PPG and Dupont, Standox are the only ones that I've used so far as a professional painter, but they seem to get the job done very well. Just stay away from that CHEAP paint, I had a bad reaction with it when I was respraying a friends rear bumper, it was metallic and it didn't lay down good at all or match for shi t





Also, you should sand it with some 600-800 grit sandpaper to ensure that the paint sticks. Wet sanding seems to work the best. Then get a scotch brite and go over it while it's wet to scratch it all up to make sure theres no shiny spots.