How to Restore Bronze, Copper and Brass
Without a doubt, bronze, copper and brass are some of the world’s most beautiful metals. With their rich, warm colour and a soft shine, these metals have been used as ornamental decoration for thousands of years. Because of this, it’s not uncommon for us to inherit or pickup copper and brass homewares, cookware, jewellery or decorations in flea markets and second-hand shops. By the time these objects find their way to you, the decades or even centuries of wear have often left their mark on these objects in the form of patina, rendering them almost unrecognisable as the bright, shiny metals they started off as. Happily, it’s not particularly hard to restore tarnished brass and copper to their former glory and in this blog, we’ll be showing you how.
What is patina?
A patina is a thin layer of corrosion which forms over many metals as they react to oxygen in the air. Tarnish is known as a ‘self-limiting’ form of corrosion (as opposed to rust) and will only affect the top few layers of metal and forms a kind of seal to protect the layers underneath from reacting.
Patina typically appears as a black or dull grey over the coating of the metal. Whilst this doesn’t sound all that appearing, the patina which appears on these metals as they age are highly prized by antique collectors and can actually increase the value of the item, depending on the type and extent of the patina.
How to remove dirt whilst maintaining the patina
If you have an antique copper or brass object and would like to retain it’s patina whilst removing dust and grime, the best way to do it is with soap and warm water.
- First, take a soft paintbrush and use it to brush away any debris
- Next, mix soap and warm water in a dish or small bucket (avoid soap containing chlorine bleach as this is corrosive)
- Get a soft cloth (like an old t-shirt) and dip it in the soapy mixture before gently wiping down the piece
- Once this is done, gently rinse the piece
- Dry immediately with a soft cloth
How to remove some of the patina
To remove the patina from brass and bronze:
- Mix 1 teaspoon salt, 1 cup vinegar and enough flour to make a paste
- Rub onto the object
- Rinse and dry
To remove tarnish from copper, make the same mixture but leave out the flour.
How to completely eliminate the patina
If you want to completely remove the patina of an object and return it to near new condition then a commercial copper/brass/bronze cleaner is your best bet.
- Rinse your item in warm water and dry with a soft cloth
- Rub the copper cream directly onto the item using a sponge or clean cloth
- Rinse again and then buff with another clean, soft cloth
Another type of tarnish is verdigris. This is a blue or green coloured substance which appears on old copper, brass and sterling. Verdigris is formed from a combination of oxygen, water and environmental pollutants. Whilst it is pretty, verdigris is corrosive and a toxic substance, so if you have it on copper cookware or jewellery, it’s probably a good idea to remove. If left untreated, verdigris will spread to other metal items close by.
To remove verdigris:
- Get a tube of cheap toothpaste and a soft toothbrush
- Put a little toothpaste on the brush and brush in the direction of the metal
- Wipe clean with a soft cloth like an old t shirt
- Once you have removed all the verdigris, rinse the item and dry it completely before storing it away
Remember that if you don’t want to keep your brass and copper, these metals have a high scrap value and are easy to trade for a profit with Metal Men. You have the option to bring your metal scrap to our Pakenham location or organise collection for larger items as we offer scrap metal pickup throughout Melbourne. To learn more please give us a call on (03) 5941 6677.
Please note that from 30th May 2018, we are no longer able to pay you cash for your scrap due to a change in Victoria’s scrap metal management laws. We offer payment via cheque or electronically.