Learn how to make an ammonia and onion patina on copper.

Step 1: Introduction:

I’ve been having a lot of fun with household copper patinas. What’s a household patina? Generally a patina created using things found in the Home, rather than, patinas made with nasty Chemicals which are not always fun to play with.

I found to my delight that many materials both organic and non organic could be used to create very unique copper and ammonia patinas. I call these materials - reactive materials.

I also had to figure out how to use those reactive materials to create patinas. I came up with a few methods which offered many possibilities.

In this tutorial I’ll show you how to: Wrap, Tie and Drizzle.

Step 2: What You'll Need.

A yellow onion (Spanish).
An absorbent cloth (I used a microfibre dishcloth from the dollar store).
A bit of yarn or string.
A zip bag.
1 teaspoon of household ammonia (from my local grocery store).
A piece of Copper.
A bit of 220 Emery.

Step 3: Copper Preparation:

It is best to first degrease your copper. This will help the patina adhere to the copper and make it more stable (less likely to flake off).

There are a few ways to do this. I recommend emery. Use 220 emery by hand or a sanding disc with a rotary tool.

Be sure to emery the entire surface and do not touch the copper with your greasy fingers. I like to wear gloves, but if you hold the copper only on the edges, you’ll be ok.

Step 4: Make It.

Slice or chop the yellow onion.

Make an onion, copper, onion sandwich (Tip: more onion is not always better).

Wrap the cloth around the sandwich evenly.

Tie securely with a bit of yarn or string.

Drizzle 1 teaspoon of ammonia evenly, a bit on both sides of the cloth.

Pop into a zip bag and let cook (sit) for 4 days.

Remove from zip bag and soak in warm water for about 15 minutes.

Open up the cloth. The onion may or may not be “stuck” to the copper. If it is stuck, let it dry completely (could be a few days), until it will flake off.