My non scientific non professional way to treating surface rust is:
- Using painters tape around the area
- Light sand paper and/or balled up foil to get the rust off
- Remove the painters tape
- Wipe down with some rubbing alcohol
- Once the alcohol dries, dab it down with some clear nail polish.
I've got bikes that I've done years ago with this method that's still holding up but I'm in the south west so...