Most bronze used in casting sculptures today is composed of 95% copper. Because of this, bronze castings and their patina finishes tend to darken with age.
Proper care can help maintain the beautiful patina surface that originally graced your sculpture.
Bronzes that are placed indoors require minimal maintenance. Many newer bronze finishes have been sealed with a synthetic lacquer finish and subsequently sealed with a coat of wax, producing a shiny wax finish.
A thorough dusting and wiping away fingerprints with a clean, dry, cotton cloth is usually the only basic maintenance required.
In a relatively dry climate, low in pollutants, and a super thin coat of Trewax® Brand Paste Wax should be applied once a year, or even every other year.
Never use spray or liquid furniture polishes to dust or clean a bronze sculpture. These polishes may contain oils which could damage the original patina finish.
In climates with higher humidity, or if you live where there is a higher concentration of airborne pollutants, cleaning and waxing may be needed twice a year.
Keep your brushes separately in labeled bags, free from other contaminants, for future use. Using a clean, dry, cotton cloth, gently rub in a circular motion, the dried wax from the bronze surface until you achieve the desired shine.
To achieve a better protective coating, you may want to re-apply a second coat using the same technique.
Outdoor bronzes require a maintenance program which keeps their surfaces clean and waxed on a regular basis.
Antique Bronze Finishes
Most older bronzes, that have been indoors, already have darkened patina finishes that have become stabilized by time. It is not necessary to clean and re-wax these surfaces as often.
WARNING: Waxing an older patina may disturb the overall character of the long acquired antique beauty. These should be evaluated by a qualified conservationist who specializes in this area. Attempts by others, to clean or wax antique bronzes, may decrease their value and damage their finishes.
Waxing once a year with a super thin coat of Trewax® Brand Paste Wax is recommended.
Applying WaxAll bronze darkens with age, however waxing may slow the process of oxidation.
To apply the wax, you need two - one to two-inch paint brushes that will be used only for cleaning your bronze. Do not use brushes that you have used for other purposes as chemicals may remain in the bristles and if transferred to the patina finish, may cause permanent discoloration.
Start by applying a protective circle of tape around the metal ferrules that hold the bristles in the brushes you are using. This will help prevent scratching of the sculptures surface when applying the wax and when dusting.
Wipe your bronze free of any dust and fingerprints using a clean, dry, cotton cloth. Use one of the brushes to remove dust from small crevasses or hard to reach places.
When applying the wax to the second brush, use three or four, back and forth, sweeping strokes. Do not dab your brush in the wax. This could cause an abundance of wax to be applied to the bronze that could harm the patina surface. Dab your brush on the lid of the wax can to remove any excess wax. Lightly apply a super thin coat of wax to the surface of the bronze using gentle sweeping motions.
Apply more wax to the brush as described, working it down into crevices.
Caution - Using too much wax may remove previous layers of wax. It is very important not to apply too much wax or work it into the surface to vigorously. Cover the entire surface with wax and let it dry according to the directions on the container.
Recommended reading for further detailed care & cleaning instructions:
The Care of Bronze Sculpture Recommended Maintenance Programs. By Patrick V. Kipper
Published by Path Publications in conjunction with
Rodgers & Nelson Publishing Co.
P. O. Box 7001
Loveland, CO 80537