Copper Metal & Mixing

Copper is Amazing  

When microbes transferred by touching, sneezing, or passing particles land on the copper surface, the copper releases ions. These ions prevent cell respiration, punching holes in the bacterial membrane and destroying the DNA and RNA inside. 

This property is important because it means no mutation can occur - preventing the microbe from developing resistance to copper. Super Bugs from common infections are killed by copper. 

Copper has been exploited for health purposes since ancient times. Egyptian and Babylonian soldiers would sharpen their bronze swords (an alloy of copper and tin) after a battle and place the filings in their wounds to reduce infection and speed healing.  

It is because of copper’s incredible characteristics that we find it so prevalently used in our world today, particularly in the medical field.

Mixing Dissimilar Metals

At times, consideration is given to mixing dissimilar metals in piping systems. Such as copper and stainless steel. This brings the potential for corrosion due to the release of these ions, called galvanic corrosion. 

The Statue of Liberty in New York was subject to galvanic corrosion. The corrosion occurred between the support structure made of wrought iron and the copper exterior of the statue. This led to the rusting of the support structure. 

Another example involves St. Mary’s Cathedral in Tokyo. A 2002 photograph of the building showed its stainless-steel roof was corrosion free. However, just a few years later the roof peeled off due to a storm. In the intervening years, the non-metal separator between the metal roof and structure deteriorated greatly. Once this inert separator was lost, galvanic corrosion caused the carbon steel support to fail. 

At the basic level, any dissimilar metals either intimately or indirectly joined (galvanically coupled) and immersed in an electrode can manifest some level of polarization and adverse galvanic reaction.