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Using Customer's old jewelry


#1

I have time to time taken customers’ jewelry and melted it down,
rolled it out and made new jewelry with it. However, I had one case
where no matter how carefully I melted the gold, it was very cracky,
so I sent it in for scrap in exchange for clean gold wire.

When I reuse silver scrap, I make sure there is no solder. I cut it
allout, grind it out, every speck of solder gone before I melt down
all the clean silver scrap into ingots so I can roll it out. Been
doing that for 8 years on a regular basis when the price of silver
and gold shyrocketed and business was bad. Just being able to reuse
my old silver and making my own wire kept me going.

As for gold, I get conflicting info. Some say I can melt down old
gold jewelry with solder. Some says I have to have clean gold scrap,
no solder. I’ve done both. I can say the gold with solder is more
prone to cracking, esp. white gold which can be a B with an Itch. I
use my judgement now when I’m confronted with mystery gold.

Joy


#2

I have used re-cast-it or Alloy 99 from stuller for many years. I
use it every time I cast. It cleans the gold and gives very good
casting results.

It even works well with 100% scrap. You add 5% by weight to the
metal being melted up and add enough pure gold to account for the
weight of the re-cast-it you are adding. I do not melt chains because
of the solder and for rings I cut out where they have been sized. I
try not to use anything with solder on it. This has worked great for
me for at least twenty years.


#3

This is a great subject, I reuse gold all the time. My question is
what is the component of solder that cause issues with reusing
"used" gold?

Steve Wandt
NaturalGoldJewelry.com


#4
Something looked funny and on closer inspection, all the so called
white gold pieces were pewter.

Maybe it’s hard for me to see, but how did you know this was pewter?

Thanks Marna


#5

I reuse customers gold almost every week and sometimes silver. Here
is how it goes in my shop: The customer is warned that sometimes there
are problems, usually pitting.

Actually, we have this in less than 25% of customer gold casting.

We don’t make sheet or wire out of customer gold. We only use it for
casting.

I usually add a bit of new metal, a high tech deox alloy. We get
ours from United Refining.

In most cases the new gold alloy we are adding makes up most of the
casting since typically the customer has just a single old ring they
want to use for sentimental reasons.

The customer is invited to watch the casting. They usually do not,
but it is fun for them and for us when they do. Sometimes we
photograph or video it for them.

The most common question from the customer is,“how much gold will I
need?” The answer is, “If you don’t have enough, we can add gold. It
actually works better that way. If you have more than enough we can
give back the leftover or credit the value towards the job.” They
almost always go for the credit.

If they have a lot of junk gold, but one or a few pieces that are
sentimental, we suggest that we only use the sentimental pieces in
the cast and just use the rest for credit.

If they have a bunch of junk gold that is not sentimental we prefer
to just use our own regular gold alloy for their job and just send
the junk off to the refiner.

We say we can change the karat by adding fine gold or master alloy,
but we can’t change the color. If their old stuff is yellow, we are
not going to get into small batch refining to re-alloy it white. Some
customers don’t care if the colors and karats are mixed together. It
is all a matter of visual aesthetics versus sentimental reasons for
using the old gold.

Steve Walker


#6

Lead contamination in the solder will cause problems.

John


#7

just out of curiosity - what alloying elements are the worst
culprits wrt shortening gold and silver alloys?


#8

Hi Marna,

Maybe it's hard for me to see, but how did you know this was
pewter? 

The look first.

It’s like looking at a lead sinker, dull and grey.

Then once the suspicions were aroused I engraved a tiny section and
the softness gave it away.

Hans


#9

I have an old book about gold making et al that I recall had some
instructions about how to melt and flux away impurities that result
in short casting. I do recall most of the techniques were hideously
toxic, but I’ll have a look and see what it suggests…


#10
I have an old book about gold making et al that I recall had some
instructions about how to melt and flux away impurities that
result in short casting. I do recall most of the techniques were
hideously toxic, 

Sounds like one or another of George Gee’s old books. He had a number
of them out around the turn of the century (1900, not 2000) or so.
Remarkably useful sources of hard to find info. One of his books is
about the only place I’ve seen the use of Ammonium Chloride used as a
"refining flux" described in sufficient detail to be useful. And yes,
he seems to rather gloss over the considerable safety considerations.
Not sure if it was a general attitude of life is cheap, or one where
reasonable common sense about safety was just assumed, or the lack of
a world where one could get sued by publishing things that someone
else used to damn near kill themselves with…


#11

Hi there

One of our goldsmiths originally trained in Hong Kong and used to
use a chemical called Mirabilite that can reduce problems with
melting down old gold. It looks like Crystals. He has tried to find
some via the internet with no joy but wondered if anyone can please
help point him at a supply.

We are based in the UK. He says that you can see what it is at
mindat.org

Many thanks and best wishes
Harriet


#12

Hi,

Mirabilite 

it’s sodium sulphate…