QuestionHi there
I have seen pieces of copper jewellery which have sections/patterns that are completely black. I think this is a powerful look and would like advice on how to do it, I have a studio set up in a spare bedroom so am unable to use extreme chemicals or other complicated techniques and was hoping this is not the case for turning copper black!
Also how would I section off areas on the metal to then turn them black?
Much appreciated
Helen
AnswerHello Helen,
there are many formulas for patination of copper and other non-precious metals.Some are cold process, some hot.I have amassed a listing of perhaps 400 different recipes over the years for colours from white to satin purple on copper brasses and bronzes. If I knew the exact colour you were after, or rather, saw I could narrow it down a bit. Nonetheless,here are a few for the brown to black range in both methods:
Use a non-metal vessel and stirring implements always
Plain old Sulfurated Potash ( Liver of Sulfur) and a half cup of warm water will darken cleaned copper.Just dissolve the LOS ( a small grape sized piece or less:enough to turn the water dark brown) in warm water- or hot water if it's cold in the room you are working in at the time.Let ti sit 30 minutes then apply.Rub in, brush, or paint it in the areas you want coloured, let dry (heating is unnecessary but if you like heat from the underside using a tripod to hold the metal above the flame ) and then rinse, neutralize with a baking soda solution and final rinse then wax to seal. If it's not as dark as you like repeat.The Liver Of Sulfur works only so long then stops depending on the concentration in solution ( you can't add too much for black, too little and you'll repeat at least three times!).
Blackish Brown:
* Ferric Nitrate... 2 oz
* Distilled Water... 1 pint
* Sulfurated Potash... 1/4 oz
Hot process ( heat metal and apply). Mix in the order given
Black:
* Sulfurated Potash grape sized lump (crushed).
* Distilled Water... 1 pint
Hot or cold process.. Use fresh solution each time. Wax over to set the colours when the desired shade is reached.
Jax brand makes patinas for copper as do many stained glass suppliers.You can find them inexpensively there, and most are liver of sulfur based..some however are glossy- which I think looks quite tacky so do read the labels for the matte effect if purchasing a pre-formulated finish.
I hope this helps.If you need more info or suppliers don't hesitate to write back and tell me where you reside so I can recommend some sources near you.
Best Regards,Ari
