You probably knew that the Statue of Liberty wasn’t green to begin with. This was the result of decades of exposing copper to the elements, namely water and air. You would’ve seen its true colors if you were around in New York around during the late 19th or early 20th century. There’s a Photoshopped version on the Internet, but it may not be an accurate representation.
However, at one point in the statue’s life, it came close to collapsing. When the National Park Service, along with an international team of experts, conducted inspections in 1981, they found that the statue was being eaten up from the inside. Much of the iron frame that supported the statue began corroding, along with some copper.
Experts identified the problem as galvanic corrosion, where metals of varying nobility come in contact, along with the effects of the elements. The statue’s location, overlooking the entrance to New York, provided the excellent catalyst (salt in seawater). Copper and iron aren’t very far from each other in the galvanic series, but the catalyst aggravated the corrosion process.
As a result, the statue had to be taken down for repairs. The corroded armatures were replaced with 316L stainless steel, which had enough yield strength to fill the role while mitigating effects of corrosion. For the most part, many of the statue’s connections remain unaffected. However, if a country’s national pride is at stake, a patriot wouldn’t have it any other way.
Rotax Metals 