How to Tarnish Brass

Why would you need to learn how to tarnish brass? It seems counterintuitive, but there are many reasons for tarnishing the finish of brass. Some examples include crafts, model making and antique replication. Although the process happens naturally, it is possible to quickly tarnish brass.

How To Tarnish Brass As Needed

Brass, an alloy of copper and zinc, has a soft golden color when it has been machined to produce metal parts. Over time, brass acquires a tarnish, which changes the color of the metal to brown with some hints of gold. When creating projects meant to mimic antique items, it is often desirable to add tarnish to new brass elements. Here's how to get new brass to look like it's been around forever:

• Remove the protective finish. Many modern brass pieces are coated with a lacquer finish to (ironically) slow the formation of tarnish. It make sense then, that the first step to intentionally tarnishing brass is to remove the protective lacquer coating. To begin, soak the brass you want to tarnish in lacquer thinner for 15 to 30 minutes and then rinse the parts in clean water. Allow your brass pieces to dry completely before continuing.
• Take a breather. Many of the following solutions can create harmful fumes, so be sure to work outdoors or in a well-ventilated area.
• Smelling salts. You can use ammonia to tarnish brass. First, find a glass container (with lid) large enough to hold the brass object. Next, soak some cotton balls or an old rag in ammonia and place in the bottom of the glass container. Suspend the brass object in the container over the ammonia soaked material using wire. Place the lid over the container and check the object every five minutes until the brass has tarnished as needed. Remove the brass piece and run it under cold water to stop the tarnishing process.
• A fertilizer solution. Any fertilizer with a high concentration of copper sulfate can be used to tarnish brass. Mix the fertilizer with water in an old bucket. Place the brass object into the solution and check it every 10 minutes until the proper level of tarnish is achieved.
• It works for stained glass. If you have access to a stained glass supply store, look for a bottled solution that is used to darken the metal strips used to hold the glass. This solution will also work with brass-The solution can be brushed on, or objects can be dipped into the solution.