How To: Adding a Patina to Brass & Copper

Find a bucket and the object you want to patina.

Pre-fuming

Pre-fuming

Add just a little ammonia to the bucket along with something to sit the item on.

Be careful not to touch the metal before fuming—skin oils leave marks (as they did in this past project).

After one week in fuming bucket.

Beautiful dark and even patina.

Some copper and brass items, like this Coppercraft Guild cauldron, add a protective coating that prevents ammonia from doing its thing as quickly. Give it time.

You can quickly and easily create a rich patina for your copper and brass with only ammonia and a bucket. You just have to endure the fumes. (These photos have not been color adjusted.)

Here's how:

1. Find a bucket you can fully seal. I use a Lowe's bucket because we fume some larger pieces, but this can be as simple as a piece of Tupperware.

2. Go outside or someplace with good ventilation. You do not want to be taking big breaths of ammonia.

3. Pour a little bit of ammonia in the bucket, just enough to cover the bottom. It doesn't take much.

4. Place something plastic or metal in the bucket that your brass/copper can sit on without touching the ammonia. I've used canning jar lids, Tupperware lids, coffee cups, and anything else that'll hold the item stably.

5. Set your brass/copper piece on its platform inside the bucket and seal the lid. Be sure not to touch the metal while doing this—skin oils will prevent the fuming from working properly.

6. Allow to sit. The longer it sits, the darker the patina. I usually go for overnight, but I've fumed pieces for a couple hours or several days.

7. Remove the piece from the bucket, wash, and dry. Enjoy.

I like to keep the fuming bucket around and sealed when not in use without disposing of the ammonia (though you will have to refresh it occasionally or it loses its umph). While it is a strong, stinky chemical, ammonia is not considered an environmental hazard. However, if I can avoid putting something nasty down the drain, I do. If you do need to dispose of the ammonia, first dilute it heavily with water before pouring it down the drain.

Look for this technique used in several pieces in our upcoming Potions Altar Set.

Note: Some copper (especially from the 1970s, like Coppercraft Guild pieces) is coated with a sealant that will need to be stripped first. So, if you try fuming and your piece for a day and comes out just as shiny as before, it's because the metal's sealed—which is what I discovered in this case. This sieve spent a day in the bucket with no change, so I knew it had a coating.

One option is to remove the sealant—some come off easily with acetone, others will require stronger chemical strippers. These are hazardous chemicals, so be sure you use and dispose of them properly, and in this case, I didn’t want to use anything so strong and unpleasant. Instead, I put the sieve back in the bucket and left it for a full week. When it came out, it had a beautiful, dark, and wonderfully even patina. So, if it doesn’t work quickly, my suggestion is to give it more time.