Re-building patina

A lot of empire / federal style bronze fixtures have a contrasting, completely black patina on some areas and gilding on others. That gives those items their beautiful black and gold look. I know the patina is sometimes actual patina, but have also seen objects where it's merely paint or black lacquer of some sort.

How should one restore such patina, if the bronze has been polished too much? The examples I've seen on auction sites always have somewhat intact black patina and was wondering if there's some special technique to it. Using just any paint seems like it could affect the value.

 

bury it in the ground for a year..

 

There's an easier way. Stick it in a brown paper bag with a banana and leave it. Works a treat.

 

What if a mole, or a raccoon digs the bronze up? Or a strong magpie flies away with it?
Jokes aside, I just read that soil contains amounts of chlorides, which cause bronze disease when they come in contact with copper-based metals.

 

Interesting, wonder why I haven't heard this before. In any case, does the metal surface have to be super clean for it to work? Is polishing required prior to the application?

 

How long does it usually take to patina? I'm assuming the metal would have to be cleaned well or even polished in order for it to work?

 

Oh...& a racoon won't go after that old banana.....

 

Peeled or UNpeeled?????

 

No, don't clean it at all. It's the ethylene given off by the banana that does the trick. Supposely, hard boiled eggs work, but I've not tried that. It's also why you ought not to store bananas close to other fruit, they ripen them. Unless you want that of course. As to how long? A day or two. Either an unpeeled banana or the skins - and then put the skins round your roses!

The sulphur thing works too and you can buy the powder in garden supply places.