Aurustamist

Aurustamist, also known as gilding, is the process of applying a thin layer of gold to the surface of a base material, usually metal, to create the appearance of solid gold or to improve corrosion resistance. The gold layer is typically much thinner than a solid gold piece and can be measured in micrometers.

Traditional gilding methods include water gilding and oil gilding. In water gilding, gold leaf is laid onto a sticky surface prepared with an adhesive, often after an underlayer such as gesso or bole. The leaf is carefully smoothed and burnished to a bright, reflective finish. Oil gilding uses a drying oil as the adhesive, which can offer more durability in some environments. These hand-applied methods are commonly used for decorative objects, picture frames, and artwork.

A more modern approach is electroplating, where gold is deposited onto a substrate from a solution via an electric current. This technique allows precise control of coating thickness and is widely used for jewelry, electronics connectors, and corrosion-resistant components. There are also variations such as gold leaf applied to silver to create vermeil or other composite finishes.

Fire gilding, historically used in some applications, involves applying a gold-mercury amalgam and then heating to remove mercury. This method is highly toxic and largely avoided today in favor of safer alternatives.

Applications of aurustamist span decorative arts, architecture, and precision components. The choice of method depends on factors such as substrate material, desired aesthetic, environmental exposure, and cost. Safety and environmental considerations are important, particularly with mercury use in historical processes and cyanide-based plating solutions in modern electroplating.