Some of my copper tape has changed colour a bit why is this?

[Nick Blair]

Some parts have changed colour, to like a greenish/purbleish bronze, why is this?

[flighty1]

It is probably a natural occurance known as verdigris (Verdigris - Wikipedia, the free encyclopedia) if so it's quite normal as the copper weathers.

[DarkCrow]

Some parts have changed colour, to like a greenish/purbleish bronze, why is this?

If it's greenish it's just natural oxidisation, the same way aluminium goes white and steel and iron rust.

[Pumpkin Becki]

Its just oxidizing Nick. Look at the copper roof of the Royal Festival Hall, its bright green with verdigris. It might reduce its effectiveness a bit, so you could rub it with a bit of wire wool to get it back to bright copper if you want.

[Nick Blair]

I have not had them long too. Can it still give the buggers electric shocks?

[HeyWayne]

Verdegris copper cladding is quite the thing in the architectural world.

[Two_Sheds]

I'm after a verdigris ironwork bench. Anyone got an opinion on that?

[HeyWayne]

I'm after a verdigris ironwork bench. Anyone got an opinion on that?

Doesn't ironwork just rust?

[Jeanied]

I have copper tape round my windowledge troughs, Nick. I'm not convinced this works totally - but seems to keep the slugs and snails at bay for a while. I always cut my finger on the tape when I put it on, and it only lasts for a while before flaking off.

[DarkCrow]

Doesn't ironwork just rust?

Usually yes but if it's for out door use it may have been plated with copper prior to it's final finish (they electro plate it to make it look like the real deal) mind you they do electroplate ironworks for the same antirust properties. usually on expensive bits and bobs thought. the main culprit for that is aluminium. TS if its ali you'll be able to move it, if it's iron you'll be be able to move it but i won't!

[Pumpkin Becki]

I'm after a verdigris ironwork bench. Anyone got an opinion on that?

T_S, I can do you a very nice faux verdigris paint effect if that helps. I can also do faux rust (seriously), limestone, granite, marble and so on and so forth

[Jeanied]

And Nick the answer to your question is that the surface of the copper turns from copper (which is the copper metallic colour) to copper oxide -(which is green) through oxidisation - which happens when it is exposed to the air.
Or to put it in scientific terms: 2Cu + O2=2CuO