How do you prep a bumper for paint?

How do you prep a bumper to be repainted (the same color). There are rock chips and spider cracks now, nothing too serious, but the qty of them makes it in need of paint. I know you can’t use paint stripper as it is plastic. So what are the step required for it to be 100% ready for paint?

sand rough stuff or pits w/ 180, then 320 the whole thing, then primer, then wet sand w/ 400, clean and paint

Do I just use normal primer or what? I saw something called adhesion promoter, it said it was for bedliners. Is this what I want to use? or just everyday auto primer?

you have to have flex aditive in the primer if you are acutally using a paint gun not a bomb can.

If you have rock chips and spider webbing on your bumper you should feather edge those spots so when you spray the primer you will not see the paint lines. You should do it with 220 since you don’t have a dual action sander, any grit lower then that and you will have tons of sand scratches in your bumper. For the rest of the bumper that doesn’t need bodywork you can use red scotchbrite pads to scuff the bumper and use 320 grit sand paper to sand the area you worked on. When you get primer make sure you get primer filler to fill in the sand scratches you might of missed, wetsand the primer with 600 grit. Clean the bumper, use a plastic prep to get the grease from touching it off and paint