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Casting argentium


#1

Are you casting with Argentium? How’s it going?

I’m asking because where I work, we use deox silver from Hoover &
Strong or Rio. I don’t like it-- it is soft, brittle, and sometimes
we get cracks in ring shanks where the sprue is attached. I’ve talked
to H&S about this, but it still happens sometimes.

And, no, the flasks are not being quenched hot, they are air cooled
overnight (per the boss-- I’m not there).

At SNAG, I had long talks with Rhonda Coryell and Cindy Eid about
Argentium, and I’m ready to give it a try in my own work. I got the
go-ahead from the boss to try it for casting, here at work.

But before we go that route, I’d like feedback from Orchidians who
have tried the current formulation of casting grain.

THANKS!
Noel


#2

Please feel free to use Stuller’s Continuum silver grain for
casting. Youare also aware of the Sterlium plus for Casting as
well…

If you need tech sheets on either. I will be happy to send them
direct or you can check us out on
http://www.ganoksin.com/gnkurl/ep819m

Andy “The Tool Guy” Kroungold


#3

We at Whaley Studios have been casting United Metals’ S57NA sterling
for years, and we could not be happier with the results. Solid
castings, very little porosity, easy to stretch or forge, and it
comes out of the investment absolutely white, free of oxidation. It
really doesn’t need to be pickled after casting, it’s that clean.
Also, the castings are not particularly sensitive to quench
temperature. We quench about 5-10 min. after casting.

Jay Whaley


#4

I’d like to hear more from casters of de-ox silver on what they use.
I have tried Argentium and Sterlium and do not care for either.
Hoover & Strong are pushing their TruSilver product. Has anyone used
that metal? My equipment is not state of the art so I need a metal
that is forgiving. I use induction melt with hand pour, and solid
flask vacuum cast.


#5

I have been using United Precious Metals S88 for years. No
complaints.

Stephen Walker


#6
I'd like to hear more from casters of de-ox silver on what they
use. I have tried Argentium and Sterlium and do not care for
either. Hoover & Strong are pushing their TruSilver product. Has
anyone used that metal? My equipment is not state of the art so I
need a metal that is forgiving. I use induction melt with hand
pour, and solid flask vacuum cast. 

I have cast sterling for 24 years. I do not see what all the fuss is
about these new alloys. Unless you are using the alloy that makes
sterling hard enough to set gems in, I do not see the advantage to
these alloys. I can solder as easy as fusing, and I do some fusing,
and use regular sterling. Just remember, who ever is selling these
products is selling the advantage, not the disadvantage you
encounter. I have enough crazy making in my life to not instigate
something else to take up more of my time. I think these alloys are
for specific purposes. Not a one fix all.

There is a trade off using these new alloys. One is simply, they cost
more. Tarnish resistant is a benefit to the consumer, but is it
justified for the potential lost sale for the increased price you
have to charge for the new alloys. I don’t think so, but I have only
been doing this for 40 years.

Richard Hart G. G.
Denver, Co


#7

You may want to try our Sterling Silver “D” Casting Grain. It’s the
most user friendly deox. Sterling Silver casting alloy we make.

Best regards,
Jim Sivertsen - United Technical Dept.


#8

Dear Noel,

We cast findings using Argentium Pro 935 silver here at Rio Grande
and have excellent results. After casting we hold the cast flask for
15 minutes and then quench in water. The cast tree comes out of the
investment nice and white. The as-cast hardness of the Argentium
silver is a little softer than traditional Ag-Cu sterling, which
makes the parts easy to clip off the tree. We have found that by
quenching after 15 minutes there are no difficulties such as cracks
and we can age harden the metal without doing a solution anneal. The
investment is still hot enough that devesting is easy. We use the
same casting parameters for traditional sterling and Argentium Pro
935 except traditional sterling flasks are quenched after only 3
minutes. Our casting temperatures are uniformly lower than those
recommended. I think alloy manufactures fudge the recommended metal
and flask temperature to compensate for inadequate sprue size. I
guess enough casters must have called to complain about incomplete
filling even though they used the recommended casting temperatures
without considering the influence of their sprue system. If a
pattern does not fill completely here, we change the feed sprue until
we get the results we need, we don’t increase casting temperatures
for a surface to volume ratio category item. The benefit of that is
we get better as-cast surfaces and we can recycle the sprue metal
because it does not become contaminated due to thermal investment
reaction. All sprue metal is granulated before using it for casting
again. Using a controlled atmosphere during melting we are able to
reuse Argentium sprue metal as long as we get it really clean before
melting it again. After casting, we cut the parts off the tree first
and then we clip the feed sprues as close to the main sprue as
possible and we tumble them together in water and burnishing compound
overnight. Tumbling is the only way we have found to reliably clean
all the investment off the sprues.

We heat treat all our silver (traditional and Argentium) before going
to finishing by heating it to 300 C (572 F) for 1 hour. I notice that
the latest recommendation says to heat treat for two hours, we will
try that to see if it improves the hardness. The Argentium comes out
of heat treat noticeably harder than traditional sterling. I believe
the hardness can be improved by solution annealing the castings
before the age hardening heat treatment, but from a practical point
of view, we find that the extra step does not make enough difference
to be worth doing. In mass finishing tests we seea vast difference
between the finished as-cast hardness and the age hardened products
for both traditional sterling and Argentium sterling. The products
finished in the as-cast hardness are not near as nice as the same
products that were hardened before finishing using the same
processes. However, we could not see a difference in the finish
quality of pieces that were solution annealed and age hardened and
those that were just age hardened without solution annealing.

Argentium silver is very resistant to the deep fire scale (stain)
that can form in traditional sterling. Its fire scale resistance
comes from the formation of an invisible surface film of germanium
dioxide (GeO2) that blocks oxygen when it is heated. The as-cast tree
emerges from the investment a bright white color because of the
presents the GeO2 film on the surface. However, in the finishing
process the GeO2 film is removed and the tarnish protection is gone.
Therefore, after finishing and cleaning, it is advisable to help
renew the tarnish resistance by doing a low temperature heat
treatment. This is done by placing the pieces in an oven at 100 C
(212 F) for three hours. A new oxide film will self-generate in time
at room temperature this is a good feature because in use, the film
on jewelry can be rubbed off but will return by itself.

In production we do not see any downside to Argentium silver. No
special casting parameters are required, it recycles well and it gets
adequately hard when it is age hardened without the need for solution
annealing. After age hardening it will take a beautiful finish. It
has excellent fire-stain resistance and good tarnish resistance when
the GeO2 film is generated. But the thing I like the most about
Argentium silver is the color. I think it is noticeably whiter than
traditional sterling silver and just attracts my eye when it is next
to darker or grayer sterling alloys. I have been told that the bright
white color helps it sell through better.

Eddie Bell


#9

Hi

I don’t do casting just send a few pieces away. But I do a lot of
fabrication.

I just use sterling and I like to be able to tripoli away the
firescale as is shows me I have pre-polished well. The final polish
is mirror. Use Hyfin for polish.

Having said that I can’t wait to try A & E’s Argentium when they
draw it in wire. I think it will take out one quenching processes for
one of my designs. As it work hardens in the fabrication process.

all the best
Richard


#10

The problem I have with S88 is that the silver tarnishes quicker
then SS which is realy awkward to me! The advantage of S88 ansd S57NA
is firescale free work but I never had an issue with that before
using SS.

Working with both is realy awsome however customers don’t need to
work with it.

They wear it and don’t like to have much cleaning work.

That’s my experience with S88 aswell as S57NA in a nutshell

Pedro


#11

Rhonda you have tried Stuller’s Grain as well. what are your
feelings. about the different grains…

Andy “The Tool Guy” Kroungold


#12
The problem I have with S88 is that the silver tarnishes quicker
then SS which is realy awkward to me! 

I was amazed to hear this, as reduced tarnishing would be the main
reason I would consider using use S88 or S57NA! Have others found
the same to be truee

Janet in Jerusalem


#13

The original person who started this thread asked about Argentium.
(not to get major suppliers to try to sell their products)

I cast Argentium Sterling regularly two to three times a
week…here is what I do.

I am usually casting 2 1/2 inch flasks, sometimes 4 inch flasks (all
custom work, small items)

  • centrifugal casting - torch (propane & oxygen) to melt and I use a
    somewhat hotter flame than I use for regular silver (for regular
    silver the flame I use is somewhat reducing, I use more oxygen in the
    flame when casting Argentium) The usual amount I cast is from 10 to
    60 grams in a flask

i) I find that I need a mix of new grain to old buttons of 60% new
and 40% old (50/50 shows some signs of a poorer cast on occasions,
but not always) I make very sure the old material is very clean

ii) I coat the material to be cast with boric acid dissolved in
alcohol, then burn off the alcohol, I use no other flux The boric
acid solution is about 30 – 40 % saturated

iii) I am careful to not over heat the metal (molten Argentium looks
different from molten sterling) I cast shortly after the metal has
become fully melted. The Argentium 935 pro appears to have a large
slush area. It does not roll as easily like molten sterling silver. I
notice that I have a few bits still adhered to the flask after
casting

iv) the flask temperature I use is slightly higher than what I use
for regular sterling (1100f for very fine items down to 850f for
larger)

v) I always let the flask cool to about 250f - 300f or right to room
temperature and I break out the cast, I do not quench. (I have
quenched hot flasks in water, the casting will crack!)

vi) The just cast material is very white. I ultrasonic clean off
investment for a few minutes only, pickle in hot pickle for a few
minutes, then ultrasonic again about one minute.

My castings are always free of porosity, never have surface pits
from contamination and work and polish well. I very often fuse (weld)
pieces together and will use Argentium hard solder and medium only. I
have never had a need to use easy solder.

I always heat treat in a small kiln holding the temperature at about
500 – 550F for an hour.

The finished cast jewellery is very white in colour, reasonably hard
and has a very good polish. Never has fire scale been a problem and
when doing torch work, I do not coat with anything at all.

My customers tell me that their items remain bright and they are
pleased. I have a little bit of evidence that those that can turn
sterling silver black when worn have much less of an issue with the
Argentium sterling silver.

I cannot comment about any of the other sterling silver alloys as I
am not at all familiar with them and do not wish to suggest that
Argentium is superior to any of these alloys.

I trust that I have been helpful.

Regards to all.

Franklin


#14

Pure does an anti tarnish silver, and they like to get things right,
I suspect that they will put the hours into getting the casting
right.

Regards Charles A.


#15
'argentium silver' confuses me. Google gives me lot of false
leads. 

http://www.ganoksin.com/gnkurl/136 Select “Technical Resources” if
you require technical

The ‘Gallery’ will show you examples of jewellery and silverware
made in Argentium.

Peter


#16
The original person who started this thread asked about Argentium.
(not to get major suppliers to try to sell their products) 

But as you know threads grow past their original scope, and
will be shared.

In Australia, we are a long way away from everything, so resources
are always welcome, especially when they are local.

As it is a lot of products that everyone in America and Europe take
for granted, we just can’t get, or can’t get at a reasonable price
and time frame. Australia being very close to the size of the United
Stated is however considered a small market by major suppliers,
possibly because it has about the one tenth the population.

Supplies from other countries cost a lot more.

Regards Charles A.


#17

How many thanks can you give to Eddie Bell.

For me, Wow, how timely was that, just what was wanted when I needed
it. on, working with Argentium.

Hand made or cast, he covered it all in half a page and all for
free.

The next step, is now that I know what My customer would be best
"served with" consult and advise. John S.


#18

Dear Colleagues,

Eddie Bell is an encyclopedia of jewellery manufacture. He never
hesitates in offering solutions for all. My experience with Eddie
Bell.

Warm Regards
Umesh. G.Chavan


#19
How many thanks can you give to Eddie Bell. 

Very useful and helpful input-- thanks very much to all!

Noel


#20

Where I work, we have started using Argentium for casting. I am very
excited about the whiteness of the castings, and the ability to fuse
rather than necessarily solder. I am impressed with the fact that the
castings are not at all brittle (unlike our de-ox castings) and we’re
having no issues except that some castings have not filled, as we
experiment to find the best flask temperature to cast at. I love the
fine-silver-like lack of firescale!

The other qualities associated with Argentium have not been tested
out yet, such as resistance to tarnish over time.

We have a question that perhaps I should ask of the techs at Rio or
Leach, but maybe someone here knows. We want to do the initial
heat-treatment to harden the castings. Can the casting be put back in
the kiln after removing the investment? It may still be as hot as
800F in there. At what temp does it actually begin to heat-harden?
Does it need to be left until it reaches 500F and then be held an
hour?

Another way to ask would be, over what range of temperatures does
precipitation hardening occur?

Thanks!
Noel