Question for Chemists

[rickbb]

Not precious metals exactly, so if it needs to go then mods do your thing.

I have come into possession of some thick copper sheeting in my scrapping adventures, not really enough to sell outright, so I though about hammering out some sculptures, yard art, fountains, etc.

Anyway, on to the chemistry question.

I want to apply a patina, light to medium dark brown. I 've looked online and most methods either require me to order or make ferric nitrate. Other methods say use a sulfur based gas by putting the copper in a bag with some mashed up hard boiled eggs and leaving it for a few days. (Hydrogen sulfide is at work here I'm guessing.)

Rather than acquire yet another chemical or having a bag full of decomposing eggs what household chemistry can be used to quickly yield a brown patina to copper?

 

[solar_plasma]

pottash and sulfur at 250°C in the absence of air will form liver of sulfur, which can be used to give copper a dark patina - be careful, this is more or less pottassium polysulfide which stinks from H2S when when exposed to humid air and will produce dangerous amounts of the gas when in contact with acids. Worth reading the msds!

https://de.wikipedia.org/wiki/Schwefelleber sorry, but the english wikipedia page about this subject isn't even worth the time to open it.

 

[upcyclist]

You can get a 1 quart bottle of liver of sulfur at riogrande.com (my usual jewelry supply joint) for $9.25. They also have other patina/oxidizing solutions, other forms of LoS (gel, solid), other quantities, etc. See http://www.riogrande.com/category/tools-and-equipment/polishing-and-finishing/Decorative-Finishes

Rio has decent prices, not the best in the world, but they sell a big enough variety of stuff that they're my main go-to for jewelry supplies--tools, raw metals, polishes, etc. If you want to get more bang for your shipping fee buck, I'm sure you can find some useful tools for your sculpture work.