I need to do some logo pins that will have a shiny silver
border and a domed, brushed silver inside with a recessed logo.
I need to oxidize (or blacken) that logo with something and
still make it possible for someone to clean the brushed silver
when it tarnishes.
G’day - hope you don’t mind if I jump in here. As you will
doubtless know, the usual sulphide blackening is no good; it
wears off inside 6 months anyway. So I have three suggestions.
One is to use niello which has been used for hundreds of years
for the purpose and is a compound of silver, copper, lead and
sulphur. Two problems here. You can’t buy it as it isn’t
commercially made. You can make it yourself (Tim McCreight’s book
has a recipe) BUT it is very hazardous to do, releasing large
amounts of choking and toxic sulphur dioxide fumes. I use it,
and it is easy to apply, but I was very lucky - a good friend on
the net made it and sent me some, and it is very good indeed. An
alternative is to use black enamel, which is a glass, BUT; you
will need your work to be in fine silver, for the melting point
of the glass enamel is very high, and great care has to be taken
to avoid melting solder or causing reticulation of sterling. It
is possible to use an epoxy resin coloured with a black pigment,
but of course, no repairs requiring heat can be done following
that treatment. Not terribly helpful, am I? But cheers anyway,