What grit are you guys using to denib or sand blemishes out of the basecoat with? I have used 600, 800 or 1000, depending on how large the problem is but usually finish with 800 or 1000. Concerned about adhesion with 1000. Also, does anyone else have a problem covering 600 grit scratches with Black basecoat? If it's going to be black, I sand the primer to 600 but it just seems to take at least 5 to 7 coats of base to cover the sanding scratches, sometimes having to sand some out of the basecoat. Have had this problem with Chromabase and now with PPG DBC. Thinking it's probably technique....