Subject: How to create green patina on copper rain gutters?

Hi,

I am buying an old house that has copper rain gutters.  On the 
back of the house the gutter has a beautiful green patina,  but on
the other sides, its pretty much splotchy black.  I was going to try to
clean off the gutters to the copper-penny look, and then let them
re-age..... but in article ID: 874601217.Ch I read....

>Patina is the result of atmospheric corrosion on copper. It is generally 
>green in colour when well established, but may be initially black before 
>becoming green. The green colouration comes from the copper oxides that 
>form. 

These gutters are 50-60 years old, but I don't know if they have ever been 
worked on or not.  Is there a *realistic* chance that if I 
just have patience and wait a couple of years that the gutters will turn 
green by themselves?  Or should I try to clean them and let the patina 
form from scratch?

Thanks for your help.

Re: How to create green patina on copper rain gutters?