Tape it off and hit it with a Scotch-brite pad, a red one. That should take care of it nicely. If you don't like it you can easily buff it back out.
best answer, you can paint over 1k grit scratches with a couple coats and it should cover. but you always need a tooth for the paint to stick.
When I paint over existing surfaces I go down to 400p for new sealer unless I will be refinishing with pearls, small flake, and some metallic (silver) paints in which case I'll take it to 600p for the 'tooth'. You're absolutely right though, once you're out of the recoat window you have to have tooth or you stand a very big chance of the paint lifting later.
some dude brought his bike to my shop in parts. paid biiig bucks to get everything, i truly mean everything powdercoated. aside from normal gloss black, he had the engine covers, pretty much anything aluminum, or steel that were random parts, coated in this fake chrome, kind of like the alsa stuff (which i have sprayed or should say washed onto parts) but waaaaaay strong. as a fake chrome it looked unpolished and kind of chinsy, but filled in minor imperfections and make the case covers pop. the kicker was that over that fake chrome was a candy blue. however having no sand scratches to grip onto, this stuff was flaking off in the pounds. getting hit with brake clean sent it into a bacon sizzling crackle and the softest fart would blow it off the part.
put in a little elbow grease and time, and im sure your tank will look dope. put up some pictures when its done bud
