I am looking for a non- toxic patina that will darken copper to any shade-- I am a metalworker in Colorado and am tired of using toxic chemicals -- does anyone out there- know anything about non-toxic patinas.
Thanks pamPam Pniak
metalworker - Durango, Colorado, USA
What does 'toxic' mean to you, Pam? I'm not being facetious: to the regulatory authorities it has the very precise meaning of materials that are on a particular list that are considered toxic by statute, and opinions have nothing to do with the subject. But to many people it means 'stinky' chemicals. The patina itself is a toxic material, and in some areas if you want to have a green copper roof on your home you need to install a wastewater treatment facility to deal with the green copper stains that runs off it.
But two possible options are eggs, which contains a high sulfur content and are capable of blackening most metal, and paints, which are not real patinas, but which can look good from a little distance, and don't involve any metals. Good luck.
Ted Mooney, P.E. RET
Brick, New Jersey