Large Metal Surfaces

• 1). Cut a lemon in half and dip the fruit side in salt to coat the fruit to give it an abrasive layer similar to sandpaper.
  
  
• 2). Pour a few tablespoons of salt on the metal surface affected by copper oxide.
  
  
• 3). Scrub the metal surface with the lemon covered in salt to remove the copper oxide. The acids in the lemon loosen the copper oxide and the abrasiveness of the salt crystals scrape away the loosened particles.
  
  
• 4). Rinse the metal with warm water and dry immediately to reduce the likelihood of rust. Polish the metal to regain its previous finish.
  
  

Jewelry or Small Objects

• 1). Fill a small container with white vinegar or lemon juice.
  
  
• 2). Scrub the jewelry or small object with a toothbrush to remove any loose particles of copper oxide.
  
  
• 3). Submerge the jewelry or other small object in the vinegar or lemon juice for 20 minutes.
  
  
• 4). Use the toothpicks or cotton swabs to further remove the copper oxide deposits.
  
  
• 5). Scrub the piece with the toothbrush and repeat the process until the copper oxide stains are removed.