The Running Horse from China and the Thinker as portrayed by Rodin – both are remarkable pieces of work and both are made from bronze. Bronze is a copper alloy as it is a mixture of copper and another other alloy (usually tin) except zinc. Because of this, bronze is more expensive than brass as well as a higher resistance to corrosion. But that is not to say bronze will have its problems.
Bronze naturally develops a patina (green coat) to help protect itself of damages that can be caused from moisture, chlorides or sulfides that can be found naturally occurring in the atmosphere. Patina can also be man-made and if that is the case, then the coating is called verde because of the reproduction (Source: www.doityourself.com/stry/bronze). Companies often lacquer to help protect the bronze of these atmospheric contentions, otherwise bronze will deteriorate rapidly.
To keep your bronze clean and protected, only a light dusty is required. One can also use a lightly damp cloth. Be sure to keep note of the lacquer and have it reapplied if you find it peeling or cracking. Dust and dirt can eat into the surface, allowing damage to occur. One of the most commonly known damage is known as “bronze disease” and it also the most serious problem that can happen to bronze. According to How to Clean Stuff, this problem occurs when there is an excess combination chlorides, oxygen and dampness. The disease is corrosion which appears as rough light green rough spots. This can be stopped by washing in boiling hot distilled water or placing the piece in distilled water and soaking it for up to a week. If the disease is not cleared up by then, you may wish to seek professional help.
To polish and keep your bronze piece clean, regular dusting and cleaning is required. If the bronze work needs a stronger cleaning and polishing, there are three ways that can help you clean and polish the work. The items needed are around from around the house and no special items are necessary. These suggestions are given by How to Clean Stuff (www.howtocleanstuff.net/things/metals/how-to-clean-bronze/)
1. Washing agent for bronze: use one tablespoon to three and a half quarts of water. Wash. Rinse well and polish with a copper polish followed by a glass wax.
2. Bronze cleaner: mix one teaspoon of salt with one cup of white vinegar. Add enough flour to make a soft paste. Apply paste to bronze and allow to sit for fifteen minutes and up to an hour. Rinse away with warm water and polish.
3. Polish: mix two tablespoons of baking soda with enough lemon juice to for a soft paste. Apply with soft cloth or gloved hands and allow to sit for twenty to thirty minutes. Rinse in warm water and buff with soft cloth. Repeat if necessary.
Further, How to Clean Stuff offers these tips when cleaning bronze:
