Traditional bronze is indeed copper and tin. But in general, that
alloy is more suited to casting than to fabrication. It tends to be
harder, and a bit brittle, depending on the exact alloy. Historical
bronzes also often had a bit of lead, which increased that hardness
and brittleness, but also made it a bit easier to melt and cast.
I’ve no idea why your magazine doesn’t like “jewelers bronze”, which
of course is also an inexact description. Most of the so-called
bronze alloys sold to jewelers in sheet or wire form are technically
brass, but lower in zinc than standard brass, hence a redder color.
If you are looking for a more traditional “bronze” color, then some
of the lighter colored brass/bronze alloys you might get could be too
light. Nu-gold is an example. It’s designed to mimic, sort of, the
color of 14K yellow gold. Some refer to it under the same bronze
umbrella, but it’s really closer to a standard brass.
Does the color of Jewelers Bronze differ significantly from a
copper and tin alloy?
The color depends on the amount of alloy added to the copper. That’s
true for true bronze as well as the brass versions. The so-called
commercial red brass often sold as “bronze” to jewelers is pretty
close to tin based bronze in color, especially after it’s been
allowed to develop a bit of patina.
If I sell a piece of jewelry made with the Jewelers Bronze alloy
and call it bronze will I be duping the customer?
No. This isn’t a distinction anyone really would care about, having
no effect on the value or utility of the work. The trade calls these
red brass alloys a bronze simply in reference to the redder color.
You shouldn’t worry too much about using the names the same way. if
you wish to explain further to your customers, they may well be
interested in the details, but I doubt the lack of that explanation
would matter to anyone.
Patina. If I follow patina instructions for some of the more exotic
bronze patinas do I have a chance that the Jewelers Bronze will
patina in a similar manner?
Similar. Maybe not exact, or at the same speed, but most of the
patinas will work about the same. Remember that different versions of
the red brasses will patina differently, but a little bit perhaps, as
will different formulations of a true bronze.
My instructor used Red Bronze when she was in school. What is that?
As noted above, commercial red bronze is a red brass, not a true
bronze. The name refers more to the color as compared with the usual
color associated with brass. You can get casting metal in a true
bronze, but not normally sheet metal, since it simply doesn’t work
very well compared to the brass alloys.
The Jewelry Artist article refers to NuGold available from OttoFrie
as a bronze. Their site, as near as I can see, doesn't say what the
It too, is a brass. Not sure if it’s just copper and zinc. I seem to
recall a bit of silver, or perhaps something else, added as well. But
the main alloy is copper and zinc, so far as I know.
There was a lot of discussion about bronze turning pink in pickle
in the Jewelry Artist article. I have seen brass and Jewelers
Bronze turn pink. I thought it was from the heat of the torch
bringing up the copper. Now I'm confused. Is it the pickle that is
actually doing it or is it a heat induced oxide that reacts with
the pickle to show up pink?
This is a common confusion. Just as people talk about “bringing up
the fine silver” when annealing and pickling sterling silver. It
doesn’t actually bring up copper with brass or bronze, nor does it
bring up fine silver. But the same thing is actually happening. In
both cases, the more reactive metal, zinc or tin in the case of brass
or bronze, or copper in the case of sterling silver, is oxidizing,
and to a greater degree than the main metal. When you pickle it, you
remove the oxides. In the case of sterling silver, you’ve depleted
the surface of the copper when you pickled off the copper oxide. In
the case of both brass and bronze, you deplete the surface of the
zinc or tin, leaving a surface of mostly copper. Unlike with silver,
this copper will also have oxidized. The outer layer of black copper
oxide will pickle off. An inner boundary of red copper oxide won’t
completely pickle off (unless you go to a more active agent, like
adding peroxide, or your super pickle). This trace of red copper
oxide imbedded in the surface rather than on top of it, combined with
the now no longer polished/bright surface of the metal, is the source
of the much of the pink color. If your pickle isn’t new, and already
has a fair amount of copper oxides dissolved, then you can get more
pink, when the zinc or tin oxides dissolve into the pickle, and cause
an electrolytic reaction that electroplates back a thin film of
copper. That surface, being even more porous and “matte”, just as it
does with silver pickled in contact with iron, is even more pink.
There’s little difference between brass and a true bronze in the
colors you get this way. The brass, since zinc is more reactive than
tin, will do it faster.
In some of the pieces I've made I liked the pink so much I left it
on there and waxed over it, but this last one I used super pickle
to get rid of the pink. The piece turned a really weird bright
yellow. What is the best method for knocking this off and getting
back to the original metal color? I sort of rubbed away for a bit
and then threw it into Live of Sulphur. It was OK, but not as good
as I think it could be.
Your choice of abrasive will remove any surface coloration and get
you back to the actual color of the metal. Pumice is a good one, or
just about any other decently abrasive material.
Then there was the mention of "metal fever" that could be induced
by zinc fumes. Wear a respirator or suffer the consequences....
yikes! In an article by Charles Lewton Brain on metal safety he
mentions the same fever thing with copper. Do I actually need to
wear a respirator with occasional soldering on either copper or
brass or bronze?
It’s probably not essential, but no matter what the metal, it’s
always a good idea to at the least have good ventillation. Metal fume
fever requires the zinc (or worse, cadmium) to actually vaporize, and
little of that happens when you just solder the metal, since it’s not
really hot enough. Melting the metal, especially if you overheat it,
is a different story. but no matter what, you’ve also got fumes from
soldering fluxes and the torch itself. Good ventillation is key.
Especially since most less expensive things like a mask aren’t
designed to remove these things, and the sort of cartridge based
respirator that actually can remove such fumes are uncomfortable, and
a bit pricey. Still, it’s good to have one around. Soldering and
melting aren’t the only operations where really good respiratory
protection is a good idea.