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Using customer's old jewelry


#1

I have a couple of customers who want me to make pieces from old
family jewelry. I am having difficulty getting it to roll out into
sheet or wire correctly, and am not sure what I am doing wrong. I am
NOT very experienced doing this, especially with the wire! I have an
old cheap rolling mill, but it generally does what I need it to when
I’m melting my scrap from purchased sheet and wire. I have a Durston
combo mold from Rio. I’m melting in a crucible, seasoned with flux.
Tried several things on the mold, but that part seems to be working
fine - currently using a spray release from Rio. Nice. So I melt it
fine, pour into the heated mold fine, remove fine. Looks great.

Then I move to the rolling mill and the problems begin. It begins to
crack immediately. I read the info sheet by Durston on the Rio site,
and it says to anneal after a certain percentage of reduction, and
to turn the piece every pass through the mill. I’m at the point of
annealing after EVERY pass, and it is still cracking before it gets
small enough to run through my draw plate :frowning:

Someone said maybe it was “old” metal? Beats me. it was marked
sterling, and certainly seemed to be sterling. I sure can’t get any
wire made though! About to pull my hair out :(I have several pieces
to make with old family silver, and some with old family gold, so
really need to get this sorted out!

Any suggestions or tips would be much appreciated!

Beth Wicker
bethwicker.com


#2

Regardless of the shape that you have cast your scrap into, sand or
file off any sharp edges and then forge the ingot over its entire
length on your anvil using whatever forging hammer you have. Forge
all sides. Anneal and then roll. As far as know, you should not end
for end until you anneal again. Anneal often, but you appear to
already be doing this. There is a very good description in the
archives of what this is all doing from a metallurgical point of
view. I can tell you that it usually works unless I have been using
some really nasty scrap. When you melt, make sure to melt thoroughly,
add some borax flux (I use a salt shaker to do this), and stir with a
graphite rod. Again read the article. I truly believe that this is an
art as much as a science. You keep at it until you find something
that works. I have made a lot of jewelry for customers from their old
metal. I try to add new metal when I can and make sure that they know
that I can not mark the final product as sterling or 14K since I
don’t know how much solder is in the scrap. Good luck. Rob


#3
Then I move to the rolling mill and the problems begin. It begins
to crack immediately. 

Usually this means your metal is contaminated with some undesired
metal. Lead is a common actor if the old jewelry had some lead solder
on it, for example, but even just lower melting silver or gold
solders can mess the metal up for rolling or drawing.

One thing that sometimes can help is melting the metal first on a
charcoal block, with flux on top. The charcoal will help reduce any
excess oxides, which can be a problem.

Much more active, if the simple charcoal block doesn’t help, is to
melt with an actual refining flux, which is something that will react
with and remove metal impurities. Sal Ammoniac, or Ammonium Chloride
(it’s modern name) is one such.

This stuff doesn’t melt the way boric acid or similar fluxes do. You
melt your metal as normal, then add a good pinch of the Ammonium
Chloride. It will skitter and dance around the surface as it
evaporates and breaks down. In doing so, it breaks down to chlorine
gas, which will react with the baser metals, forming chlorides of
those metals. These are generally insoluable in the main mass of
metal, so they float to the top and are removed as slag. However,
note that I said Chlorine gas. If you do this in a closed room,
you’ll have a room filled with a pretty blue haze, which won’t seem
too pretty because you’ll be kinda busy coughing. Chlorine is toxic.
So this is something to do outside, or with very good ventillation.
Stand upwind. But with cracky metal, especially scrap gold in lower
karats where your scrap often may have amounts of old solder, the
Ammonium Chloride procedure can make a really surprising difference.

Peter Rowe


#4

Hi Beth,

I have the same issues with people wanting to use their own metal.
My standard line is that I will be happy to take it to the refiner
for them, but that I will only use fresh metal when fabricating.

Very likely you have solder mixed in your metal, corrupting it, and
causing all the cracking. If that’s the case, I don’t know of any way
to fix it.

Just offer to refine it and start with good fresh metal.

Best,
Maggie Glezer


#5

Hi Beth,

I tend to forge on my ingots a little bit before I try to do
anything else with them. Typically just a basic ‘all over’ reduction
pass with a very large ball peen.

(Usually, it’s the front face of a blacksmithing forging hammer
(about 2 lbs) which is ‘flat’ but actually a very, very large radius
ball. (like 10+ inches radius) Just slightly rounded, in other
words.) I also inspect the edges, and cut off anything that looks
like it might be thinking about cracking before I start rolling. (go
for a long cut parallel to the edge of the sheet that you’re worried
about, just inboard of it by ‘some’ distance. Whatever you do, do
NOT make deep “V” cuts, or any sort of notch. Those will force it
to crack. Long, slow curves with a long radius you can get away
with, but nothing that’s going to concentrate the stress.

Are you trying to do wire or sheet?

What I’m afraid of is that you’ve gotten something into it that
contaminated it. Did you clip out all the solder joints before you
melted it down? If not, the solder may be the root of your problem.

Alternately, you may have missed a piece of god knows what that was
lurking in one of those pieces. Either a spring, or an earpost, or
something else that wasn’t sterling.

If that’s the case, you’re talking about small scale refining before
you get anything useful out of it. Peter would know much more about
that than I would. Here’s hoping he’s reading this.

Regards,
Brian


#6

Hi!

For a start, I would never melt down a piece of jewelry that was
hand made i. e., that has solder on it! A cast piece is another
story, it may be OK. Here is what I found to be the most helpful
post on melting here at Orchid, which I saved:

Melting scrap silver
https://orchid.ganoksin.com/t/melting-scrap-silver


#7

Thanks to all who responded on and off-line! A great help. I’ve read
the Ganoksin archives also.

I suspect there must have been either solder I missed, or something
I thought was silver that wasn’t. I’ll try once more using the
various suggestions, and if it doesn’t work just let the customer
know it will have to be finished in new material. I did get a
successful ingot to make the pendant out of - I’ve pierced and sawn
that, and carved it, to re-use the customer’s stones. it is in
trying to roll wire to use that I’m failing.

I have read and watched some videos on home refining, and decided I
don’t want to go there - much too toxic for me!

Thanks again for all of the help!

Beth Wicker
bethwicker.com


#8

If I have to use old gold I heat it up to reveal the solder seams,
saw through them and then file the edges to remove the solder and
then reheat to see if there’s anything left. If I’m in doubt I’ll
take out more than than I think I need. Then I add new gold - of a
higher karat if I can - and melt.


#9

I don’t do it.

Don Meixner


#10

Melting scrap silver
https://orchid.ganoksin.com/t/melting-scrap-silver

In this posting from Leonard (he was a bully but what a knowledge he
had!) he mention the use of soda as an better alternative for borax,
has any one had experience whit using this alternative when it comes
to sterling?

Before I blow out my basement workshop, is sodium carbonate
decahydrate the same as soda mentioned in this posting?

Re reuse of sterling, I my offend purist, but cutting out solder
seemse Is this not over the top, when I melt 100 gram of sterling,
cutoff pieces failedprojects (happen to me all the time) how much
solder will be in the mix? 1gram? The one gram holds 60 pro cent or
more pure silver, forget the 7.5% copper in sterling we are talking
about 0.4% When I melt used silver I pour the silver slowly in an
large metal bucket, or big flower pot of water, then I placed in an
acid bath for a day or so, the next day I use it for mainly wire,
casting or sometimes sheets. You have to change the water after each
pour, as you will notice there is always a dark layer floating on
top of the water after the pour, dust sand etc I assume.

Sawdust I first souk in borax and melt and pour in the bucket as
many times needed, most of the time two times

Peter
Spain


#11
I suspect there must have been either solder I missed, or
something I thought was silver that wasn't. 

Very easy to do, Beth.

The following pictures are from a gold antique ring that came in for
sizing to my workshop.




Something looked funny and on closer inspection, all the so called
white gold pieces were pewter.

As you can see, some considerable craftsmanship was applied.

The center collet was also pewter.

Also note the unusually cut diamond center stone.


#12
The one gram holds 60 pro cent or more pure silver, forget the
7.5% copper in sterling we are talking about 0.4%

Those 0.4% is enough to get you into trouble Peter if we are dealing
with lead.

I agree with you.

Their is nothing wrong by reusing silver. It’s a metal like another
one with specifications you have to know an deal with.

However, people insert al kind of metals into it (lead, pewter,
cadmium and iron are the most knowen ones).

That is where trouble starts, right there.

The next person doesn’t know about it, melts the silver down with
lots of blue and green colores and a room filled with nasty smoke…
bin there done that.

That is the reason why I have a ventilation system build, I’ve
learned something after all.

For ones, I have the privelage in Europe to have the opportunity of
a company (Fischer Pfordzheim) who can provide me with a powder based
on potassium nitrate for cleaning silver.

http://www.ganoksin.com/gnkurl/ep823j

In short terms it means: powder + silver + time + heat = result nice
cleaned silver to work with.

If the first run doesn’t do it all then the second will.

Another way is using chemistry which invalves working with acids.

Sure, you need to know and understand the process.

The point is, I’ve learned it and I’m not strong in chemistry at
all.

Helping hands are ready to be found all over the world! If I can do
it, anyone who whould like to know it can do it aswell but you have
to pay attention and stay focussed.

Now that I know about it and learned how to work savely I’m glad
that I made this step towards facing this issue.

I have a nice jar with pure cleaned silver and one problem less to
deal with just by perserverance.

I’m sure there are many way’s to clean silver with recipes I’ve
never heard of.

For what it’s worth it.


#13

Dear Colleagues,

We normally dissolve the old customers Jewellery in Aqua-regia &
obtain Pure gold. We normally donot smelt the old jewellery using
various fluxes.

Umesh


#14

Hey Beth, (happy belated birthday before I forget!!!) betting I’m
late and what i’m going to suggest has been said- Old Silver-

  1. If it’s flatware - make sure you remove any stainless tines and
    contaminants from handles, candlestick bases and even handles of
    platters- the easiest thing is to grind off the solder remnants, etc
    (a lot of manufacturers used stainless knives and filled holloware
    with everything from lead, to wax and plaster (sealing/setting wax)
    to add weight and “balance” the piece in the user’s hand! I can’t
    tell you how many sets I had to pour wax from before packing it to
    send to the refiner or melting it for scrap /recycling raw materials.

  2. Then there are bits of solder: Run a magnet over what you believe
    is a ready-to-melt lot/pieces and if something reacts keep cleaning!

  3. Refining flux- Ammonium Chloride/Sal Ammoniac mixed with
    pure/activated charcoal 1:3, in a small metal spice tin that closes
    well (Sal Ammoniac draws humidity from the air- so mix what you’ll
    usse in a day or three…

(use an old McCormick’s type tin with a shaker and spoon capable
top): add to the crucible to yield a bright tough ingot that wont
crack ( Provided your rollers are level !!!)

Use a graphite rod to skim off any gunk that the refining flux (in
an ordinarily prepared/crucible glazed with borax crystals) reveals
from the scrap- try and add up to 30% 'new metal" to fabricate and/or
alloy your raw materials into usable stock. The refining flux is
great when karating gold, or alloying colours from your scrap. For
sterling if you have access to an XRF tester, test some pieces ;you
may need to add a bit of .999 to standardise it, particularly if it’s
really old/ an antique silver service. (if it keeps cracking and
splitting even with frequent annealing it may be higher in coper than
you thought! Contact me with your weight and I’ll reply (promptly- I
promise!!!).

Those are some basics. Of course dedicate gold and silver crucibles
and glaze well. Have a graphite rod for skimming handy and just steam
clean before melting- don’t polish pieces or do anything to
treat/shine the metal-Just check it all well fro solder, fillers, and
content…


#15

So I finally remembered to look up refining fluxes as mentioned in
AE Smiths Working in Precious Metal circa 1934.

Ammonium Chloride which decomposes to chlorine.

Mercury Chloride

Potassium Nitrate - probably the nicest; strong oxidiser and
desulphur agent

Potassium cyanide…

So. Um. Aqua Regia looks like the safer option…