Re: What do I need for wet sanding repaired paint chips and small scratches?
For feathering the chip before painting, you can use 1000-1500. After the paint cures, you use 1500, to 2000 to 2500 and then polish or use 3000 and then polish. 3000 is the finest you would use for paint. There are industrial papers that go up to 6000, but there is no point in using that for paint. It would not do much, and would likely load up with paint and scratch more than it made it smooth.
After it cures, put water in a spray bottle with a drop of car wash soap in it to reduce the loading of the paper. Spray the area well while sanding and check your paper often for little particles of paint on it. Use another piece of the same grit of paper to clean your paper with, to prolong it's use. Spray the paper with water first as a lube and cleaning solution.
After you sand the area to blend it with the surrounding paint, I would polish the area by hand in that area. lastly, you can use a machine to get the area perfectly even.
Meguiar's makes excellent paper in the higher grits like 2500 and 3000. Soak the paper in water before use as directed.