How to brighten copper products when they are blackened and oxidized?

An oxide layer will be formed on the surface of copper products after oxidation, which will make them black, but this will not affect the quality of copper products. If you want to brighten it, you can try the following methods:

Cleaning with lemon juice and salt: mix lemon juice and salt, gently wipe the surface of copper products with the mixed solution, then rinse with clear water and dry with a dry cloth.

White vinegar salt cleaning: mix white vinegar and salt, smear the mixed solution on the surface of copper products, let it stand for a few minutes, and then wipe it clean with a clean cloth.

Cleaning with flour: mix a proper amount of flour and a small amount of vinegar into paste, apply it to the surface of copper products, let it stand for about half an hour, and then wipe it clean with a wet cloth.

Precautions:

Do not use acidic or alkaline cleaners to avoid damaging copper products.

Do not use too hard brush or grinding tool to clean, so as not to scratch the surface of copper products.

Before using any cleaning method, please test whether the cleaning method is suitable for inconspicuous parts of copper products.