sealing an oxidized silver ring
horatioB
the oxidization wears off after time especially since it is a ring. I
am using liver of sulphur to oxidize the silver. Does anyone know of
a different process or some sort of seal that would keep the
oxidization on the ring longer. I have heard of using clean nail
polish but it makes the pieces shiny which i would like to avoid.
Thank you,
hb
mbstevens
Niello, enamel, and plating would be worth investigating.
Peter W.. Rowe,
The nail polish sorta works, but it's not all that nice a solution. Kind of
denies the nature of the material...
Oxidized surfaces on silver have traditionally been used because silver does
this on it's own, naturally, so doing it intentionally not only gives the artist
some control over the look, but makes the piece look older, sometimes a desired
impression (thus the term "antiquing" is sometimes used for this too.)
Normally, the black is applied to recessed or more protected areas, and lightly
buffed off of high spots, resulting in a finish that closely mimics what time
will do, and the way time will maintain the finish in use.
If you want an overall black, even on high spots, you're then battling the
nature of wear and tear, but there are some things you can do that will slow
this down.
Plain blackened surfaces, straight from the liver of sulphur, are a dull black,
in which the sulphide (we call it oxidizing, but it's actually a sulphide that's
formed) is a somewhat loose and porous surface film. This surface wears off
somewhat more quickly than it could if compacted. If, after blackening, you use
a soft brass or nickle silver scratch brush, wet with soap or similar lubricant,
the wire brush burnishes the sulphide down into the surface some, compacting it.
the result is no longer a totally dull black surface, but it becomes a sort of
blue/black or gunmetal color, with a low sheen to it. Very pretty, at least in
my opinion, and it's somewhat more durable than the original black surface.
Getting the best finish can take two or more applications like this. patina,
scratch brush, patina again, scratch brush again, till the color gets the depth
you want. Key is that the brush, used gently and lubricated, isn't abrasive the
way it would be if used dry. You can get hand brushes called "platers" brushes
that are an especially fine guage of brass wire in the brush, so it's a very
soft and gentle brush. Works great for this.
The other thing you can do is in how you texture or define the original surface.
High spots wear off before low spots, and if your surface is deeply textured or
carved, most of it can be essentially, low spots, so the black will wear off the
overall surface more slowly. Hammer textures or carved, engraved, roll printed,
or other textures will all function this way. Even subtle textures like a sand
blast or bead blast surface will have their blackened color wear down more
slowly than a smooth polished surface would do. And the texture of some of
these, like the sand blast, also will give you a much deeper color, since the
texture greatly increases the overall surface area.
Hope that helps.
Peter
Rick
heated to produce a black oxide on the surface, which is quite durable.
Rick Hamilton
"Peter W.. Rowe," <rec.craft...@earthlink.net> wrote in message
news:njqt04t324lcvh0is...@4ax.com...
Peter W.. Rowe,
<stdu...@comcast.net> wrote:
>>You could also replace the silver band with one made from niobium- it can be
>>heated to produce a black oxide on the surface, which is quite durable.
>>
>>Rick Hamilton
Or titanium, which also can heat treat to a nice durable oxide, though the
niobium black is a deeper/darker color. The titanium is somewhat harder and
more durable, which is nice, and a whole heck of a lot cheaper, which is very
nice.
Both metals, though, make poor suggestions for many people, since they cannot be
soldered via the usual methods used with silver, so fabricating a ring from them
can require major changes in the design to allow cold connections like rivets or
screws, machining parts from solid stock instead of forming from sheet, or other
means of not needing to solder parts together or seams closed. So a direct
substitution of these reactive metals for the silver is often not practical. But
it's still a good thing to remember that these metals can be colored like that.
Titanium in particular is interesting for heat coloring, since more modest
heating gives a lovely and fairly intense dark purplish blue, rather unusual by
itself, and impossible as a mere patina color on other metals.
Both metals can be given a wide range of colors by electrolytic anodizing.
Again, the colors on niobium are more intense, but the titanium, especially if
starting with a matte or sandblast or etches surface, is pretty darn intense
too.
Peter