Protective Coating in Bronzes

In this sculpture, most of the surface alterations were calcareous deposits due to hard water used for garden watering. They were eliminated  with a 10 % solution of sodium hexametaphosphate in distilled water. Afterwards, it was necessary to rinse thoroughly with distilled water to eliminate any residue. Some crevices with unstable corrosions were treated to remove them and prevent further damages. For most outdoors bronze sculptures, the best coating we can generally recommend is wax. Wax provides a flexible coating, is easily applied and can be frequently renewed. It protects original patinas and can be used on top of lacquers. The only previous measure is to perform a good cleaning first. Microcrystalline waxes  are recommended in most cases, because they are inert and will not yellow over time. If applied evenly to a degreased surface and buffed out carefully with soft rags and bristle brushes it can protect the surface of the sculpture for a good period of time. A yearly or biyearly maintenance treatment is recommended to preserve the surface characteristics.