Wet or dry sandpaper to Polish my motorcycle frame?

A. Hi, Bob. Sorry to be tedious with a semantics issue, but it will explain why you are hearing what sounds like contradictory information. When metal finishers speak of "polishing", they probably mean the intermediate step between grinding and buffing. But you probably are not interested in stopping at a rough polish stage . . . you are probably looking for a fully shiny "buffed" finish.

So if someone says they "polish" with sandpaper or scotchbrite, they mean they rough polish; you can't get to a shiny buffed finish with sandpaper whether wet or dry. For that you need soft cotton or flannel buffing pads mounted on an air tool, and a lot of work, probably with progressively finer buffing compounds -- these compounds are "waxy" in texture.

Although small parts can certainly be buffed with a Dremel [on eBay or Amazon], and it's a good way to practice and learn, practicality probably demands a bigger tool than that for large parts.

Letter 21746 and letter 800 go into great depth about polishing and buffing motorcycle parts. I think you'll find just what you are looking for there. Good luck!

Regards,