New brass is shiny with a golden-tint, and slowly acquires a dark, almost bronze color as it ages. Aged brass is favored by many decorators as a classical, dark look that helps accentuate a room. Unfortunately, it takes many years for brass to age naturally, which isn’t applicable to many decorators’ needs. In order to speed the process up, you can “antique” brass at home, which involves using chemicals to age the mental prematurely.
Using steel wool or a wire brush, briskly scrub the new brass to remove the invisible seal that was applied to the metal after it was forged. This step is necessary, since the metal won’t antique while the seal is in place.
Put the brass in a plastic bucket that has a tight-fitting lid. Do not place the lid onto the bucket yet.
Acquire a glass jar or cup of some type and fill it with ammonia; the specific amount of ammonia doesn’t matter, though a larger amount will work faster than a smaller amount. Put the ammonia-filled glass item into the bucket, then put the lid on and press it firmly in place. Ammonia fumes will fill the bucket and begin to age the brass, causing a patina (greenish coloring) to form on the metal. Leave the brass in the bucket until the patina is as dark as you’d like, then remove the metal and wipe it off with a damp rag.
Use steel wool or a wire brush to scrape the metal if you want an aged, brushed-metal look. Move the wool or brush in different directions, using short, sporadic movements, otherwise the resulting scratches will resemble brush strokes and will look unnatural.