Whats the cause and the effect of Acid rain that has turned a bronze statue green.

Question

Help:)

Answer 1

Most, if not all bronze statues I've seen out doors for any length of time have a patina formed on them and need to be cleaned periodically.  It happens everywhere.  Good luck.

Answer 2

it is the chemical reaction of the acid with the copper content of the bronze which is an alloy.

Answer 3

Acid rain doesn't make bronze statues green, any rain can do that, over many years of course.... It turns green because the oxygen in the air reacts with the copper atoms to form copper oxide, or the green that forms. Acid rain probably harm bronze, but don't make the mistake of thinking its only acid rain doing it, and not normal rain.

Answer 4

The green color is referred to as verdi gris and is natural or applied patination of the surface and in fact, in part, once it's formed, slows the rate of further deterioration and is often purposely put on at time of manufacture. And it's removal can seriously damage and devalue an artwork!

Answer 5

I believe it is the sulfer or nitric acids in the rain that reacts to the iron mineral in the bronze, attacking the minerals color cells and causing the color in the statue to fade to the grimy green color of the acid.

I think there is some kind of polish or protective coating you can use to coat the statue with that will counteract the acidic poisens in the acid rain. Then again it is best to sheild the statues from harmful rains that can't really be avoided.