Oxalic Acid Method

• 1). Shut off the enamel cooktop, and remove all cookware. Let the cooktop cool completely.
  
  
• 2). Prepare to use oxalic acid crystals, which are poisonous. Put on acid-proof gloves, protective garments and safety glasses.
  
  
• 3). Fill a pail with 1/2 cup of warm water. Sprinkle 1 tablespoon of oxalic acid crystals into the water. You may purchase oxalic acid crystals at hardware stores.
  
  
• 4). Stir the solution until all the oxalic acid crystals are completely dissolved.
  
  
• 5). Drench an absorbent sponge in the oxalic acid solution. Tamp the rust-stained portion of the enamel with the saturated sponge to soak the rust in the acid solution.
  
  
• 6). Let the acid solution permeate the rust for three minutes. Oxalic acid is extremely powerful and works quickly.
  
  
• 7). Saturate a rag with water. Wipe up the oxalic acid solution and the dissolved rust.
  
  
• 8). Rinse the rag thoroughly with water. Wipe the enamel again to flush away any acid residue. Thoroughly rinse the enamel cooktop.
  
  

Sodium Borate and Lemon Juice Method

• 1). Turn off the enamel cooktop, and remove all cookware. Let the cooktop cool completely.
  
  
• 2). Pour 4 ounces of sodium borate into a container. Add 2 ounces of lemon juice, stirring the liquid into the sodium borate. Stir the mixture until it’s smooth.
  
  
• 3). Spread the mixture over the rust-stained portion of the enamel using a spatula. Let the mixture dry on the cooktop.
  
  
• 4). Saturate a rag with water. Wipe the dried mixture and the dissolved rust off the enamel cooktop.
  
  
• 5). Rinse the rag thoroughly with water. Wipe the enamel again to flush away any remaining residue. Thoroughly rinse the enamel cooktop.