Rear bumper I have a couple areas that a will be spot repairing. Base and pearl spot then clear whole bumper.

question is how do I prepare the clear to spray clear over it. Sandpaper 1000 grit, scuff?

 

Pics first before going ahead. And you want to try polishing compounds first before trying to wetsand and buff it out

 

Put clear over clear how do you promote adhesion

 

The new clear should cohere to the old clear coat just fine as long as it's CLEAN. Something polar (soap and water or isoproanol) to remove biological stuff (bugs and things), followed by a non-polar chemical (gasoline or lighter fluid) to get the tough residuals and old wax off.

 

2 bucket method wash using dawn dish soap
Clay bar with 3 different grits rough to fine
Use random orbiter with wet mop head using cutter medium grit then fine
Polish with wet mop using polisher and then wax

 

Go over ALL areas to be cleared with a scotch brite pad. The areas must be fully cleaned and scuffed for the correct paint adhesion over the original clear.

 

If you do respray the clearcoat remember to blend past the repair area