Buccacio Sculpture Services LLC in Canton, Massachusetts cleans & restores Bronze. For smaller unpatinated pieces, you might consider the following recipe:

Bronze is a copper alloy (combination of copper and tin) and when exposed to air and moisture, it will develop a greenish layer of build-up on its surface. This greenish coating is known as patina. While this darkened finish does add character to the bronze, some consider it unsightly, and would prefer their bronze to look clean and shiny. There are two basic homemade polishes you can use to clean and polish your bronze. Using either method will help you safely remove the patina on your bronze pieces and restore their luster and shine. Both methods are equally as effective, so the choice is yours.

DON’T DO THIS: DO NOT use sugar instead of baking soda on bronze. It will damage the bronze.

Baking Soda & Lemon Juice

What You Will Need:
Warm water
Clean towel
Small dish
Soft cotton polishing cloths (smaller size)
Lemon Juice (from concentrate is okay)
Baking soda
Rubber gloves (optional)

• Rinse your bronze items in warm water, and dry thoroughly. This will safely remove any dust and/or particles that may hamper your polishing efforts.
• Place about 2 tablespoons of baking soda in a small dish.
• Drizzle a small amount of lemon juice onto the baking soda and mix until a soft paste forms (start out with just a little lemon juice and add more as needed). It is normal for the mixture to bubble at first, and will settle down after a moment or two.
• Apply the paste to your bronze item using your hands (with the rubber gloves) or with a small polishing cloth.
• With a polishing cloth, rub the paste onto the item using small circular motions. This is the key removal step and you may have to rub repeatedly until the desired effect is reached.
• Allow the paste to stay on the item for 20 to 30 minutes.
• Rinse the item thoroughly with warm water to remove the paste and buff dry with a clean towel.

Additional Tips and Advice

• In lieu of polishing cloths, try using an old white cotton tee shirt, cut into squares.
• This process, while relatively simple, takes time and patience as the greenish patina may be quite stubborn and will require a bit of elbow grease to remove.
• If the bronze item is small or has a lot of crevices and tight spots, try using a soft bristled toothbrush to rub the paste into hard to reach areas.
• Although occasional polishing will keep your bronze looking shiny, using these methods too often may have the opposite effect, reducing the luster of the bronze finish.
• Maintain your bronze items by regular dusting and rinsing; regular care will keep your bronze looking it’s best and lessen the need for more frequent polishing.
• When you rinse your bronze items, be sure to dry thoroughly. While bronze is resistant to moisture, allowing it to remain wet and air-dry will hasten the formation of patina.
• There are some commercial polishes available for bronze (usually in specialized stores or online). Some of these products can be harsh and are generally no more effective than the above polishing pastes