Copper corrosion is the familiar green and hard rash on copper. But what exactly is copper corrosion and how does it work? And more importantly, can corrosion be removed and can the copper be restored to its original state? In this blog we will discuss these questions and present a good and simple solution to get rid of corrosion of your valuable copper.
What is copper?
Copper is a metal that has been processed by humans for a long time. Excavations found copper utensils from over 10,000 years old. The beautiful red colored metal belongs to the so-called transition metals, a group of metal that is widely used in modern technical applications, but is generally (except iron) pretty scarce. This also applies to copper, and therefore the metal is a lot in the news recently. Thefts of copper cables and other copper material of railway sidings, energy and telecommunications companies are reported frequently. Even artworks of copper and bronze are not spared. This is, of course, directly linked with the prices paid for old copper. Where the scrap dealers barely pay 20 pence a kilo for old iron, copper is worth 15 or 20 times that amount.
Copper has properties that are particularly useful for certain applications. One of the features is its insensitivity to corrosion. This is reflected in the quality of ancient brass parts on old rooftops and buildings. A much better known property of copper is how well it can conduct both heat and electrical power. A large part of the copper in the world is used for electric cables and coils, for electric motors and generators. In addition, copper is also relatively easy to manipulate. That’s why we see it in art, utensils, musical instruments and boilers. And of course, copper is also used for water service pipes. Finally, copper is the basis for the widely used metal alloy bronze (an alloy of copper and tin), and brass (copper and zinc).
What is copper corrosion?
Corrosion is the corroding of, mainly, metal – but also ceramics and plastics can corrode – due to environmental effects. The most well-known form of corrosion is the electro-chemical reaction in which water and oxygen react with metal and oxidizes. Corrosion, however, can also be caused by acids and by galvanic or other reactions. Also, burdening of the metal can play a big role in whether the metal will corrode or not. Stress corrosion and fatigue corrosion indicate that metal corrodes faster from the inside when burdened with respectively static or dynamic tension.
In general, copper is highly resistant to corrosion. Not because it does not corrode, because it does corrode. But because the corrosion stops quickly. When iron rusts, a porous layer where water and oxygen can penetrate remains, so the rusting process can continue unimpeded. Sometimes you can only see a small spot of rust on the outside of an object, while the inside or back side is already almost completely rusted away.
When metals such as copper, aluminum, zinc, nickel and lead corrode, a closed oxide layer forms which further closes off the metal, and the corrosion stops. Iron and steel will completely rust through without treatment, copper will get a green-black oxidation layer, also called patina, after which the corroding process stops.
How can we remove corrosion from copper?
The layer of patina protects against further damage and in some cases is also considered pretty. But of course there are also copper objects from which you want to remove corrosion, to show the original copper in its full brilliance. In these cases, we need a solution where the corrosion can be easily removed, without damaging the copper. Ferrocon is therefore an excellent solution. Ferrocon is applied to the metal with a brush, roller or – for larger areas – a low-pressure sprayer. After using Ferrocon you can simply rub the dirt off and the end result is the copper as it originally was. After cleaning, you still have to give the copper a separate treatment to protect it against new corrosion.
With corroding metals such as iron and steel, Ferrocon converts rust into a tough primer layer that also protects the metal. With copper and other metals that only form an oxide layer, but otherwise do not rust, no hard primer layer is formed and you will therefore still have to separately apply a protective layer. There are, for example, specific primers on the market that are suitable for the protection of copper. But for the cleaning of the copper itself, Ferrocon is the perfect solution. Your copper will look like new.