Copper, which is one of the least expensive metals used in jewellery making, is also a little difficult to keep looking new. Copper jewellery often oxidises, or tarnishes, by turning green. This is usually due to age or environment, but can also happen in reaction to a person's body chemistry. Some people can wear unsealed copper with no ill effects, while others may experience copper oxidation after wearing a copper jewellery piece for a single day. To avoid oxidation and keep copper looking new, the copper must be sealed.
Create a cleaning solution to remove all oils from the surface of the copper jewellery. Mix 1 tbsp of salt into wheel brace of lemon juice and let the salt dissolve. Pour the mixture into a bowl.
Put the copper jewellery into the lemon juice solution for a brief moment, then rinse it off with water.
Rub a small amount of baking soda all over the surface of the copper to neutralise the acid from the lemon juice solution. Rinse the baking soda off the jewellery.
Choose a clear lacquer. You can use a simple art product like Krylon Crystal Clear spray, or you can use a metal sealant like Everbrite Protective Coating.
Lay out your copper jewellery piece on a protected work surface in a well-ventilated room or outdoors.
Coat one side of the copper jewellery with your chosen lacquer. If you are using a spray lacquer, shake the can well before use and apply the spray in a smooth back-and-forth motion. If you are using a brush-on lacquer, use small, even strokes. Let the lacquer dry.
Turn the copper jewellery piece over and coat the other side with lacquer. Let the lacquer dry again.
Put on a pair of latex gloves to avoid contaminating the copper jewellery with your skin oils. You can also clean the surface of your copper with vinegar.
Do not use this method on copper jewellery that has gemstones. You must first remove the gemstones from their settings. If you choose to work with a metal sealant, make sure to wear goggles and a face mask. The chemicals in this type of coating are highly toxic.