Remove oxidation and tarnish from copper using ketchup, a flour and vinegar scrub, a salt-based scrub, boiling in salt and vinegar or by using sulfamic acid. Citric acid is effective in cleaning copper, and an easy oxidation removal method involves using a lemon half to scrub the copper piece with salt.
Scrub a tarnished piece of copper with, or submerge completely in, acetone to strip away the oxidation and corrosion and expose the shiny copper surface.
A lacquered piece of copper requires that the lacquer is removed before any additional steps are taken to clean the piece. Remove the lacquer by mixing 2 cups of warm water with 2 tablespoons of mild dish soap, and spray the mixture onto the piece. Allow the piece to sit for a few minutes before wiping away with a soft cloth and then rinse under warm water. Dry completely using another soft cloth.