Copper and brass develop an unsightly brown or green tarnish (patina), over time due to the oxidation of the copper on the surface of the item. This is a natural process and needs to be attended to regularly during the life of the copper item.
Unfortunately many commercial copper and brass cleaning products, and tarnish removers, contain formaldehyde an other harsh chemicals that can be toxic and dangerous to the skin and lungs.
Fortunately you can make your own safe, effective and inexpensive homemade copper and brass tarnish removers and polishes.
These remedies are non-toxic and do not damage your copper cookware, ornaments, decorations, sinks, kitchen utensils, coins and jewelry. These homemade remedies use simple and widely available natural ingredients available in most kitchens.
It is unwise to attempt to clean valuable copper coins, which should only be cleaned and preserved by professionals. Always check before cleaning antiques, jewelry and other valuable copper items as this may decrease their value.
This article provides advice on home remedies for cleaning copper and brass items and preventing tarnishing.
Tarnish (patina) is formed naturally through oxidation of the copper on the surface with oxygen. The patina actually prevents the copper underneath from corroding. This applies to many metal surfaces such as silver, stainless steel and aluminum. Copper that has been exposed to air, will get a dark brown patina as it tarnishes. If the copper is exposed to moisture as well as air, it will get a greenish-blue patina. Both of these patinas can be removed with weak acid solutions and very mild abrasives.
The combination of vinegar and salt is generally suitable for mild tarnishing. The acidic vinegar dissolves the oxidization that causes the tarnish and discoloration. The salt is a very mild abrasive that can help remove grime and stains. Simply dip a cloth or sponge in vinegar and rub over the tarnished area. For any stains that remain, simply sprinkle a little salt on the cloth and rub the area. Rinse the cloth in vinegar again and rub over to remove any remaining salt.
For tougher stains, make a paste from vinegar, salt and flour. Mix one tablespoon of salt with one cup of vinegar and add flour gradually to make a thick paste. Spread the cleaning paste onto the tarnished areas and leave it on for 30 to 60 minutes, depending on the severity of the tarnishing. You can also place items in a pot and boil to remove stains. Dissolve about one tablespoon salt in one cup of white vinegar in a large pot. Top up the pot with water and add the copper object so that it is fully immersed. Bring the solution to the boil and simmer gently until the tarnish comes off. Remove item and allow to cool, then wash with soap in warm water, rinse and dry with a towel.
Add some vinegar to a spray bottle. Spray the tarnished area with a little vinegar, sprinkle on some baking soda, which will fizz when it reacts with the vinegar. For tougher tarnishing, spray a cloth with a little water and add enough baking soda to form a paste on the cloth. Rub the tarnish with the cloth. The baking soda provides a very mild abrasive action. Spray on the vinegar and wipe off with a damp cloth.
Lemon juice can be used as a replacement for vinegar. To clean copper ornaments, pans, pots and jewelry, simply sprinkle salt on a lemon wedge.Rub the tarnished area with the salt covered lemon wedge, and then wash and rinse the surface with warm soapy water. Simply wiping the copper surfaces with lemon juice or a lemon wedge is a good regular remedy for tarnishing. As above, baking soda is used as an abrasive and it also reacts with the acidic lemon juice producing a fizzing cleaning reaction. You can also use salt with lemon juice.
Using ketchup and tomato sauce to clean copper sounds weird, but ketchup is acidic and it contains vinegar and salt. Simply wipe the tarnished area with ketchup and rinse off with warm soapy water.
Don't use the cleaning solutions described above to clean copper sinks. The sink probably should have a coppery-brown tarnish color, rather than a bright shiny copper glow, that is impossible to maintain without using lacquers. Sinks are best cleaned with plain soap and water and a scouring pad (fine scratches don't really matter).
Copper that is cleaned may tarnish again relatively quickly. So, what can you do to prevent it? Essentially you have to provide a barrier that stops oxygen and moisture from getting to the surface. This can be done using oils, waxes and a number of clear lacquers that are available. Below are a few suggestions: