I have solely worked with Sterling Silver until I recentlypurchased
some Argentium sterling silver to experiment with. I fabricated a
pendant bezel setting by bothsoldering and fusing. I did not use
anyboric acid flux during the process. Whe nI polished the piece, I
noticed there was firescale on the back of thependant. I thought you
didn’t need toworry about firescale with Argentium. Any suggestions?
Thanks inadvance for your help
Bernadette Johnson
Hi all
did you pickle and polish the piece? When heated Argentium gets an
oxide on the surface, this is not firescale and is removed by
pickle.
all the best
Richard
I noticed there was firescale on the back of thependant. I thought you didn't need toworry about firescale with Argentium.
There are two forms of oxide that form on silver. One is firescale
and the other is firestain.
The two terms are often somewhat confused, with firescale being
misused for both types.
Firescale is the usually black or gray oxide and discoloration that
forms on the surface of the silver when heated. It’s primarily a
copper oxide. It comes off in the pickle leaving a matte white
surface.
Firstain, on the other hand is more subtle, being also a copper
oxide, but imbedded within the surface layer of silver, to a variable
depth depending on how hot you got the metal and for how long, and
under what level of oxidizing atmosphere. So you pickle off the
firescale, the silver looks clean and white, and you then go to
polish the piece, only to discover that the metal is still slightly
discolored, with a faintly reddish or creamy white tone. You don’t
normally see it except for where you polish through it to the clear
clean silver underneath. Unlike firescale, which being a surface
oxide, is easily cleaned off in the pickle, firestain penetrates,
forming part of the surface layer of the silver, and generally has to
be removed along with that thin surface thickness it’s reached. That
can be more than a little annoying. It can be damaging to the piece
if you have to take off too much metal, or the appearance can be
damaged if you cannot get it all off.
Historically, it was dealt with by using a number of types of flux,
such as Prips flux, to protect the metal from that oxidation
(ordinary boric acid in alcohol, as is used for gold, won’t quite do
it for silver). Another way is to simply accept that as the final
surface. The famous Scandinavian silver firm of Georg Jenseon was
well known for their firestain finish. After their pieces were
totally finished and polished and very clean (no flux or anything),
the pieces would again be annealed carefully, so as to be sure the
fire stain layer reached everything. Then pickling and minimal
polishing saw to it that the layer, and thus the surface color,
remained uniform.
With Aregnetium and similar alloys, the biggest worry that these
alloys prevent is that deep penetrating oxidation, the firestain. You
won’t get any of this on such alloys.
However, although they prevent most of the firescale too, they won’t
prevent all surface discoloration on heating, especially in those
areas that are not protected by a reducing flame. Thus you got some
oxidation on the back.
But you should have found that it comes off quickly and easily in
the pickle (more easily than the firescale comes off of standard
sterling) Even fine silver, which has no copper in it at all, can
sometimes discolor a little on heating, especially if there is
anything containing sulphur around. Silver does form an oxide, though
it’s not strongly bound, and is essentially colorless. But sulphur
and a few other things can also bind to the silver, causing some
discoloration. And Argentium or Sterlium alloys are more than just
silver. You avoid or minimize the problems from copper oxides, but
the metal still benefits from being protected during heating.
What I saw on my Argentium must have been firestain. It did not come
off in the pickle and reallyonly showed up once I fully polished the
piece. I had to repeat the polishing steps to remove it. It sounds
like this is an oddsituation.
Bernadette Johnson
There go’s the reputation of argentium silver being firestainproof.
I wonder under which condition CATRA performed their firestain test
and yes I know that they described I downloaded them (both) but
practice and statements from others show otherwise.
Are we all doing something wrong here?
So, if Argentium does oxidize being "7 up to 8 time stronge"r then
other silver alloy’s, Does that mean that regular silver get’s
oxidized in 1 day compared with Argentium?
Frankly, I never noticed that but reading the PDF- reports from
CATRA that’s how it sounds.
I worked with Argentium (960 to be specific) aswell as with S88,
S57NA (from UPM) and regular sterling silver.
They all will oxidize but not in the rate as I’m supposed to
believe.
I must complete my writing that S88 and S57NA are not mentioned in
that report.
I’m just talking out of experience with the different alloy’s.
Now the same with the firestain PDF-report.
As the report shows, the’re is no firestain to reveal after
performing that test.
Their test is performed with 1 trial (I think) and with one
temperature (580 C).
However, firestain will start forming from a broader range of
temperatures.
Why only testing at this temperature?
It all becomes fuzy to me realy.
I’m confused with all the statements of people ranking Argentium so
high.
The funny thing is that you can’t do much wrong other then buying
the product as it is and following the working procedures.
I’m not setting the rules and I don’t have all the testing abilities
but what is left to believe? Being a gold- silversmith with enough
experience to know what to do and not, I understand others problems
very well.
They are trying to make a wonderful piece and just don’t get the
results.
I do start to believe that Argentium is promising more then it can
stand for pointing towards firestain and oxidizing.
This is an attemption to place the company in a bad spotlight, not
at all.
Fact is that many people are confused -as I am- and they don’t get
the solving answer to a straight forward question.
So, what makes the difference between a perfect argentium workpiece
and the troubles people encounter with this alloy?
Whatever you call it, I’ve had the same thing happen. My conclusion
is that it is important to give the Argentium an opportunity to
"grow" an oxide layer by gentle heating without flux before doing
extensive soldering, and to stay away from charcoal as a soldering
block. Beyond that, using the recommended fluxes should help. I’m
not an expert, maybe one of those kind folks will chime in.
Noel=
I really do not know what to say except I have been a metalsmith for
over 20 years. Around 2005 or 06 I was in a conversation at SNAG with
Sessin Durgan about the Argentiun alloy. He was forging with it at
the conference and it was so white and beautiful that the minute I
got home I ordered a good bit of the metal and the soldiers from
Stern Leach or Houser Miller, not sure which. I loved it so much
Immediately! The only thing I knew is that it did not need as much
annealing for forming, it brazed at a cooler torch temp and it was
hot short so give it a second to cool before moving.
I also loved the very slow to tarnish quality. I packaged every
scrap of traditional sterling except some 4 gauge wire and sent it
off. I bought 5000 dollars of argentium and have never looked back. I
have really never had a minutes worth of trouble with the changeover.
I do not use charcoal, I use solderite for the boards. I have never
seen any fire stain, but I do spray the flux as that is the way I was
taught in the production studio where I began my career an I find it
really a fast way to work. I use ph down for pickle. I have found the
alloy faster to fabricate due to the less number of annealing rounds
and much easier to clean up and finishing. I do not mass tumble and
my finishes are satin with high points and edges at a high polish. In
the 10 years of solely using this alloy I have not encountered andy
of the problems others speak on the many forums. I read the entries,
but I have yet to experience many of the experiences. I have never
used the heat hardening techniques as my work, being hammered and
formed it is usually very hard at the end of production.
I really do not have troubles with this alloy. I think that Peter
Rowe is correct on the firescale/firestain concerning the alloy. I do
use a squirt of peroxide in the pickle sometimes to boost the
cleaning power of the heated solution.
I have been a metalsmith for over 20 years. Around 2005 or 06 I was
in a conversation at SNAG with Sessin Durgan about the Argentiun
alloy. He was forging with it at the conference and it was so white
and beautiful that the minute I got home I ordered a good bit of the
metal and the soldiers from Stern Leach or Houser Miller, not sure
which. I loved it so much Immediately! The only thing I knew is that
it did not need as much annealing for forming, it brazed at a cooler
torch temp and it was hot short so give it a second to cool before
moving. I also loved the very slow to tarnish quality.
I packaged every scrap of traditional sterling except some 4 gauge
wire and sent it off. I bought 5000 dollars of argentium and have
never looked back. I have really never had a minutes worth of trouble
with the changeover. I do not use charcoal, I use solderite for the
boards. I have never seen any fire stain, but I do spray the flux as
that is the way I was taught in the production studio where I began
my career an I find it really a fast way to work. I use ph down for
pickle. I have found the alloy faster to fabricate due to the less
number of annealing rounds and much easier to clean up and finishing.
I do not mass tumble and my finishes are satin with high points and
edges at a high polish.
In the 10 years of solely using this alloy I have not encountered
any of the problems. I read the entries, but I have yet to experience
many of the experiences. I have never used the heat hardening
techniques as my work, being hammered and formed it is usually very
hard at the end of production.