Content

• To step
• Method 1 of 3: Oxidizing copper with boiled eggs (light or dark brown)
• Method 2 of 3: Oxidize copper with liquid solutions (green, brown or other colors)
• Method 3 of 3: Oxidize copper by other methods
• Tips
• Warnings
• Necessities

If you want to give a rustic, antique look to copper jewelry or other copper objects, you can have it corroded in a controlled manner. With copper we call this "patina". You can patinate copper yourself without spending a lot of money. The patina layer can turn dark brown, but also green or greenish-blue. Results vary by method, so feel free to experiment with multiple methods. The liquid solution method gives you the most control over the end result.

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Method 1 of 3: Oxidizing copper with boiled eggs (light or dark brown)

1. Hard boil two or more eggs. Two or three eggs is more than enough in most cases, unless you want to oxidize large amounts of copper. Put the eggs in a pan of water and let them boil for at least ten minutes. Don't worry about overcooking. That greenish edge and sulfur scent is just what we want because sulfur will tarnish the copper's appearance.
2. Remove the eggs from the water with kitchen tongs and put them in a plastic bag. The eggs are very hot, so it is best to put them in a bag with kitchen tongs, preferably a resealable plastic bag. If the item doesn't fit in a plastic bag, you can also use Tupperware, a sealable bucket, or any other container that you can close with a lid. But the bigger the container, the more eggs you will need.
   • A container or bag made of clear plastic is the most convenient, because then you can easily keep an eye on how the copper is changing without having to open it.
3. Break the eggs. First, partially seal the resealable bag to prevent pieces of egg from falling out of the bag. Beat the eggs in the plastic bag with a spoon, the bottom of a cup, or some other heavy object. Break up the skin, yolks, and egg whites until you have many small pieces.
   • Do not close the bag completely, because if the air cannot escape it is difficult to break the egg.
4. Place the copper objects on a small saucer. This will prevent the objects from coming into contact with the eggs. Because of the saucer you will not have to remove the egg from the objects and it prevents stains where the egg has touched the copper.
5. Place the saucer in the bag and seal the bag. Place the dish with copper objects in the plastic bag. It does not matter if the saucer is placed close to the pieces of egg, as long as the egg does not touch the copper. Seal the bag tightly to keep the sulfur vapors in, or put the lid on the container if you are using a container. The bag will expand due to the heat of the eggs, but in most cases the bag will not break.
6. Regularly check that the objects have the desired appearance. You can probably see results after 15 minutes, but you will need to let it sit for 4 to 8 hours to achieve a dark brown patina. The longer you leave the copper in the bag, the darker it will get, and larger areas will start to look old and stained. When you have achieved the desired result, remove the items from the bag.
   • Wash the items after removing them from the bag to remove any leftover egg, once the items are clean you can better see how it turned out.

Method 2 of 3: Oxidize copper with liquid solutions (green, brown or other colors)

1. Sand the copper object with a sanding pad and water. Sand the object in straight lines to evenly sand the metal and you'll get a nice, non-smudge patina. If you want to create a high-contrast work of art with a new look on the one hand and worn and old on the other, you can skip this step or experiment with cleaning pieces of copper.
2. Clean the copper object with mild dish soap and rinse the soap thoroughly. Remove soap, grease and other layers from the copper. Wipe and pat the copper dry with a soft cloth.
3. Make a solution based on the color you have in mind. There are several solutions you can use to oxidize copper, depending on the final color you want to achieve. Most of the remedies mentioned here are normal home remedies that can be bought at the supermarket or drug store.
   • Warning: when working with ammonia you must wear gloves at all times and ventilate the work area well. Safety glasses and a respirator are recommended. If you do get something on your skin or eyes, rinse it under running water for 15 minutes.
   • For a green patina, mix 480 ml of white vinegar, 360 ml of pure ammonia and 140 grams of salt. Put this in a plastic plant sprayer and mix it until the salt dissolves. The more salt you use, the greener it will become, so use less salt if desired.
   • For a brown patina, mix baking soda with hot water in a plant sprayer. Keep adding baking soda until it no longer dissolves.
   • There are also products for sale that are specifically designed to make copper look older. In that case, follow the instructions on the packaging.
4. Take the copper item outside or put it indoors where there is good ventilation. Put newspapers underneath to protect the work surface underneath.
5. Spray the item at least twice a day. Spray the item and wait an hour to see what happens. If you can already see the color change, you can spray some new liquid on the object every hour, aim the plant sprayer at the places where the patina is not yet clearly visible. If nothing has happened after an hour, you can spray it twice a day until you start to see the patina. Leave the item outside to accelerate oxidation.
   • If you want to be able to better control where and how the patina forms, you can rub the object after spraying with a scouring pad, copper brush or cotton swab. Wear gloves and safety glasses if the solution used contains ammonia, acids, or other corrosive chemicals.
   • If it is very dry, you can place a plastic bag or cloth over the item to keep it moist. Place the plastic or cloth on a frame or between two larger objects so that it does not come into direct contact with the copper.

Method 3 of 3: Oxidize copper by other methods

1. Give your copper a green and blue patina with plant food. With concentrated plant food you can quickly oxidize copper. For a blue patina, mix one part plant food with three parts water, for a green patina, mix one part plant food with three parts red wine vinegar. Apply the solution with a plant sprayer or rag, and don't apply it too evenly if you want it to look naturally aged. After 30 minutes you will see the patina develop, after 24 hours it is permanent.
2. Place copper in a mixture with white vinegar. White vinegar creates a green or blue patina on copper, but then you need a different substance to keep the moisture with the metal. You can soak the copper in a mixture of white vinegar and salt, or you can bury it in sawdust or even crushed chips and pour white vinegar over it. Place it in a closed container for 2 to 8 hours, check the color regularly, remove the object and let it air dry. Remove the remaining dirt with a soft brush.
3. Create a clear blue patina with ammonia fumes and salt. Fill a container with a 1/2 inch deep layer of pure ammonia, outdoors or in a well-ventilated area. Spray the copper with salt water and lay it above the surface of the ammonia, on a wooden block. Cover the tray and check every two hours for discoloration. The patina should turn dark brown with blue hues. Remove the item from the tray and let it air dry until it is bright blue.
   • WarningAlways wear gloves and safety goggles when working with ammonia. Do not use the container you used to store food or water after this.
   • The more salt you use, the more the color will change.

Tips

• Only use the tray and plant sprayer you used to patinate copper after this.
• The patina will last longer if you apply a product to treat copper. Do not use water-based products if you have patinated with ammonia.

Warnings

• Never mix ammonia with bleach or other cleaning agents.
• Provide good ventilation if you use ammonia, especially if you work indoors. Make sure the ammonia does not come into contact with your eyes.

Necessities

• Sanding pad
• Mild dish soap
• Plant sprinkler
• Sealable bag or tray
• Means to treat copper (to keep the patina beautiful longer)

One or more of the following:

• Water
• salt
• Vinegar
• Concentrated plant food
• Baking soda
• Ammonia