how do i keep liver of sulfur patina on enameled copper?
by lindsey
(dallas)
I enamel cuff bracelets that are 14g copper... I love the liver of sulfur look but it rubs off after i stabilize. I can't dip enameled (glass) jewelry into super hot water or it will crack the more delicate pieces. Ideas?
Stacy's Answer:
Hi Lindsey!
I've heard that in order for enamel to remain the most stable and durable, you must coat both sides of the metal with the glass - although I know that often this is not done. Liver-of-sulfur will only oxidize clean metal. If it's not making contact with metal, nothing will happen.
Since you seem to be getting an initial patina layer on areas of your copper, but it rubs off, that seems to indicate that as you say, your metal is not hot enough. Cooler solutions and metal form a velvety, gunky layer of blackish crud on the metal that rinses or wipes away without truly oxidizing the metal.
You do not have to super heat the copper, just bring it to a very warm temperature slowly by running the tap water over it and increasing the temperature until it is hot. (hot, not boiling!) The glass should handle being heated slowly as you're not using extreme temperatures with this process. Super heat the LOS solution and apply to the areas you want it using a Q-tip or a small, natural soft bristle paint brush. You can keep the metal warm by simply rinsing it in hot water and the LOS solution warm by placing it on a hot plate. (be sure to use a container that can withstand the hot plate!) Re-apply the LOS as needed until you have the depth of the patina you want.
Let it cool down on it's own and then dry completely before carefully scrubbing with a fine 3M scrubbie pad or fine steel wool to remove some of the patina. You can then follow up by buffing with a polishing cloth depending upon the finish you are trying to achieve. Left on it's own, unprotected copper will oxidize, eventually turning brown like a penny.
An other idea is to add an enamel coating the color of the patina you are wanting to get in those areas. That would be a permanent solution - or so it seems. I do not enamel so I cannot give you any help with that. But it seems like a doable thing!
