In my last post I mentioned that liver of sulfur (which works well on sterling silver and great on straight copper), is not intended for use with brass.  So, just what does work?

If you do a little online research, you'll find that some artists swear by simple household vinegar. I have tried this many times, using various methods, and never been satisfied with the results. (Yep, I tried cooking brass in an oven, setting it out in the sun, and suspending it on a string inside inside a jar with paper towels, etc etc.)

Not surprisingly, plain vinegar is not the technique used by professional brass oxidizers like the Vintaj company. (In fact, Vintaj uses a painstaking, proprietary, seven-step process to achieve their gingerbread-brown results.)

If you set out to darken your own brass components, be patient and allow yourself some time to experiment. I recommend the following approach.

Pre-Cleaning

Wash your components completely before working with them. Use a mild solution of water and vinegar, mild dish soap (like Dawn) diluted in water, or a mixture of ammonia, mild soap, and water. This is essential because any dirt or oil on the brass will keep those areas from darkening.

Tip: According to Tim McCreight in his book The Complete Metalsmith, you can confirm that brass is clean by pouring water over it. If the water sheets across the entire surface of the metal, rather than beading up, then the piece is clean. He also recommends wiping metal with alcohol just before oxidizing.

Darkening Chemicals

Ferric nitrate is a popular chemical for oxidizing brass. You can purchase it through a general chemical supplier or through a larger jewelry supply house, such as Rio Grande. To prepare the antiquing solution, dissolve a 1/2 teaspoon ferric nitrate in one pint of distilled water. For best results, slightly heat the brass in a low-heat oven, and then apply the solution by brushing or spraying. Allow the solution to dry, and check your results. Repeat the application -- and complete drying -- until you achieve the color you're looking for.

Another, more complicated, approach is to add 1 teaspoon of the chemical ferric chloride to your ferric nitrate solution. This is called a "Florentine" solution and creates a richer patina. Apply the solution as usual, and allow it to dry. When the color changes to light brown, you then need to rinse the brass with cool water and dry it using a piece of slightly-damp newspaper. (I'm not kidding.) Next, brush the surface of the component completely with 00 steel wool, and allow the brass to sit for at least 12 hours. You can repeat the entire process as many times as necessary to achieve your desired color. (Pretty labor intensive, eh?)

Important: Both of these methods could expose you to potentially toxic chemicals, so be sure to follow all safety precautions provided by the chemical manufacturer and supplier.

Protecting the Finish

After darkening, you can allow your brass pieces to continue to age naturally, or you can temporarily seal the finish with a thin coat of beeswax or a paste wax. To apply bees wax, you may need to warm the brass component in a low-heat oven or with a hair dryer before rubbing-on the wax. Alternatively, you can use a prepared paste wax, like Renaissance Wax or Johnson's Wax, which is soft enough to apply without pre-heating.

Got more oxidization tips? Please share! :)

This post contains an affiliate link to Amazon.com.

I'm honestly stoked to discover that my affiliate partner Blick carries my favorite liver of sulfur formula! In case you've forgotten, liver of sulfur (also spelled "sulphur") is the chemical you use to intentionally darken sterling silver or copper to give it an aged or antiqued look. It works on most copper-containing metals (sterling silver contains copper, as does true bronze -- but most brass contains very little copper, so remember: it's not intended to darken brass).

Dry vs. Liquid Liver of Sulfur

Back when I was doing higher production silver work, I would buy liver of sulfur in dry chunk form instead of liquid. The idea is to dissolve a chunk of the chalky, sickeningly green and stinky stuff in warm water before applying it to your metal. That can pose some serious challenges. Here, in lovely list form, are the problems I've encountered:

1. Dry liver of sulfur deactivates pretty quickly if exposed to moisture, so if you accidentally introduce even a drop of water into its storage jar, you can lose the whole batch.
2. The chunks are all different sizes, and many are quite large -- up to a half inch or so across. But you usually only need about a pea-size chunk for a given application. I've found it very difficult to break the larger chunks into manageable sizes without flipping them across the room, turning them to dust, or getting them wet.
3. Dry liver of sulfur is usually sold in large quantities, with prices to match. This wouldn't be a problem if it lasted -- but all liver of sulfur (to my knowledge) deactivates naturally over time. It's pretty frustrating to set up your work area for oxidizing and have your jewelry ready to go, only to discover that your liver of sulfur is dead. (Dead = It simply doesn't work; your jewelry takes on no color, very little color, or worse, an undesirable yellowish or orangish color.

So finally one day, after discarding yet another big jar of the dry stuff, I decided to try a liquid version. Although it also degrades naturally over time, it's sold in smaller quantities and is much more affordable. It also eliminates the need to dig into and break up stinky chunks of potash. Just pour a bit into a cup or bowl of warm water and you're on your way. And if you don't use up all of your liquid before it does break down (which I've found to take months), you'll probably know just by looking it: It's color changes and little bits of potash will float around in the bottle.

You can find these little bottles of liver of sulfur at various jewelry making suppliers, in addition to Blick. Feel free to comment if you have a favorite alternative supplier!

(Click here to learn more about my affiliate partnerships.)