Ormolu & Hardware
Gilt Bronze
Ormolu, the French term for gilt bronze, refers to the process of applying a thin coating of gold to a base metal, such as copper, brass, or bronze. This technique was mastered and popularised by French craftsmen throughout the late 17th, 18th, and 19th centuries.
Background
Gilt bronze, or ormolu, is synonymous with opulence and luxury. The original technique seen on high-quality furniture was developed in France. It is a process by which high-carat powdered gold is applied to a base metal using mercury and amalgam. This mixture is then fired in a kiln at very high temperatures to burn off the mercury amalgam, leaving behind a thin coating of gold. Gilt bronze and brass were reserved for only the highest quality pieces, while plain brass is also widely used and more commonly seen. The highly toxic process of mercury gilding declined and was banned in 1830.
Gilt Bronze handles off an English piece. They only required a light clean.
A pre French Revolution commode. The hardware of this piece is brass.
Process
It is extremely important that ormolu is correctly identified and not confused with brass or Bbonze. The coating of gold is extremely thin and easily worn through.
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Correctly identify gilt work as opposed to hardware and mounts made out of solid brass.
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It is extremely important that mechanical cleaning with abrasives is avoided.
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Over the years wax and grime will build up. These adulterants are gently removed and a hard wax applied.
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Solid brass hardware can be treated very differently to gilding. More aggressive cleaning can be pursued if needed.
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Frank is not an advocate of over cleaning, buffing or polishing. When it comes to cleaning gilt bronze and brass, less is more.
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Hinges, latches and locks are often made of brass and steel and may require some repairs.
It is important to retain original hardware, as replacement hinges are seldom the same size, and the screw holes rarely align properly.
Old brass hinges often wear out. Frank will repair the hinges rather than replace them. In this case, small brass shims were fitted to resolve the wear.
Simple brass handles. This is a very old piece from the William and Mary period, dating to the late 17th century. The handles have been cleaned and waxed.
The mounts on this high-quality credenza are cast brass, not gilded. They were removed, cleaned, polished, and then waxed.
This small side table is by François Linke. It is an exquisite piece of the highest quality. François Linke was a Parisian cabinetmaker active in the late 19th century and early 20th century.
Outcome
Correct identification is critical; it takes experience and a keen eye to recognize the subtle differences between ormolu-gilded bronze and plain brass. Ormolu, the French term referring to the process of applying finely ground gold to cast metal, such as bronze, needs to be treated with extreme care. Conservation soaps and hydrocarbons can be used to gently clean the gold.