Outdoor bronze sculpture can can retain its original look and luster by following a few simple preservation tips. The process described should be applied at least a once a year, preferably late summer before winter sets in, typically a day when the temperature outside will reach 90 degrees or higher.
The first step in the process is to throughly clean the bronze removing any dirt or foreign elements. This is a simple process and can be accomplished by first brushing off any loose dirt with a soft bristle brush, followed by a through washing with a mild dish washing detergent using a sponge and soft brush to scrub off stubborn stains. Once you have completed the clean up with soap and water rinse the entire sculpture throughly. Having rinsed the sculpture you now need to completely dry it, use an automobile sham or lint free towel to dry the major areas, a electric or gas powered leaf blower will do an excellent job of completing the drying. Allow the sculpture to warm up after the final rinse and drying, once the bronze has warmed up in the sunlight it is time to apply the wax. Renaissance Wax or Johnson Paste Wax are two good waxes for this.
Ideally the bronze should be heated and the wax applied to the hot bronze, however this is not always viable for the homeowner, and you don't want to scorch the surface of the bronze. This is where allowing the bronze to heat up naturally under the hot sun comes in for the average person. Once the bronze is warm take a hair dryer or hot air gun and heat the wax in the can until it starts to soften and melt. Here again the can of wax can be set out in the sun and allowed to heat up. Liberally apply a coat of hot wax over the entire sculpture, allow this coat to dry, buff lightly and then apply two more coats of wax to the sculpture, these coats can be applied cold. Using a soft rag buff the wax between each coat. This will protect your bronze sculpture for the upcoming year.
Every third year you need to have the sculpture professionally cleaned, and the old wax coatings removed, this prevents the sculpture from going darker due to the many coats of wax. The wax removal process uses chemicals that should only be handled by professionals.
Follow these procedures and your treasure will remain looking good for generations to come.