This is Heather in England, been on this group a few times in the past
with a few questions... here's a new one.
I am mainly working with gold at the moment and wondered if there's a
way I can create my own solder's using the filings I get rather than
spending money buying fresh material.?
I work with 9ct gold, 18ct and 22-24ct gold which includes bullion.
I understand there are different grades you can make so that you can
carry out soldering in one phase and then add another group of features
soldering with a different grade... and then repeat again... is this so?
Is this complicatied?
Is there a basic easy solder recipe for using up 9ct gold scraps.
Greetings and salutations...
I have not done this myself, although I have been looking
at getting into a bit of jewelry design and repair...In any case
it is my understanding that one can use the next step down in
purity as a solder...so in your case, 24 ct would be soldered
by the 18 ct, the 18 ct by the 9 ct.
I am sure that more knowlegeable folks than me will
give a better answer moments after I post this, though (*smile*)
I wouldn't know but I'm going to guess it starts with copper and zinc
additions... I'd look up the compositions of some typical alloys. And
wait to see if Abrasha or Harold have anything on the subject...
The same dealer that sells you the gold and the gold solder should also be
willing to buy your filings. Your recovery should be about 90-95% (Harold
please correct this estimate). Unless you have your own reprocessing
facilities for gold filings, this is your best bet. So now that the value
of the gold is out of the equation, here are some reasons for NOT making
your own solder.
1. Commercial solders have known karat ratings. Typical is 10, 14, and 18
2. Commercial solders with known karat ratings have known melting
temperatures. Important when soldering several joints near each other.
3. And this is the most important -- color. There's yellow, pink, white,
and green gold and various shades between. If yo make your own solders
you're unlikely to get the color right. A yellow gold piece with green,
pink, and white solder joints isn't going to look right.
4. Save some money and trouble and don't buy precut solder. You buy solder
in a small sheet -- e.g., 1cm x 2cm and cut off tiny pieces as you need
them. That way, you can afford to have several different melting
temperatures on hand. However, to take advantage of this you will have to
buy some really good, jeweler's tin snips. Expect to pay about $50 last
time I looked.
You can make a reasonable solder for just about any carat yellow gold
by mixing it with 10-20% by weight hard silver solder, melt it (mix
thoroughly), make a bead and roll it out thin. This will give you a
solder with similar working properties to the equivalent "hard solder"
for that karat gold that you would get from a supplier. But since you
are in the UK, please note that this is NOT a "plumb solder" -- use
much of it in a piece, and you are likely undercarating and may not
pass the assay requirments! I've done it a couple times for repairs,
mostly, and once to make 22kt solder when I needed some real quick
over a weekend.
If you can find an old book, "Jewelery Workshop Techniques" in a big
library, there are a bunch of solder formulas in it.
However, all that said, you are much better off buying solder from a
good supplier, as you will get known karatage, melting points, color,
and working properties. It's really not worth it to recycle your
scrap as solder, IMO. Better to use it in your next cast, or melt it
down and make sheet/wire, or just send it to the refiners.
San Francisco, CA
There is no fixed recovery rate. So much depends on the work habits of each
benchman that I was never able to make predictions. Results were wide and
varied. The lowest recovery rate I experienced, and it was routine for
that particular company, was around 20% (of the gross received weight).
They included wax, toothpicks, saw blades, dog hair, chicken sandwiches ,
etc. etc., in their filings. Their polishing waste was worse yet. On
the other hand, I had one customer in Arizona that had a diamond cutting
machine and kept his filings clean. Very clean. My recovery from that
operation was nearly 100%, based on 14K gold, assuming the gold was not
plumb, which, at the time, it likely was not. The refining process is
quite precise, with very little gold lost to the function, although as the
quality of the batch received drops, the loss increases due to drag out.
The lost gold shows up in cleanup, so it is not lost.
As a matter of policy, filings are best not re-used. Speaking from the
position of a refiner, where you get the opportunity to see the crud
included from a bench, the gold would have to experience a considerable
reduction of quality, often manifesting itself as porosity in castings and
brittle gold that would not roll or otherwise work well.
Unless you have your own reprocessing
My experience in dealing with some of the larger refiners left a lot to be
desired. They have a reputation for being dishonest, and my experiences
with a few of them told me it is a well earned and deserved reputation. The
very best scenario for the small consumer is to hope to find a small scale
refiner that is trustworthy and stick with him. The negative side is that,
for the most part, people like that generally do not offer alloyed gold, nor
solders. My operation returned pure gold shot almost exclusively, along
with silver crystals, washed and dried, right out of the silver cell. It
was beyond my ability to produce any of the alloys or solder on an
economical basis, and I was so busy with refining that I had no time to
pursue it anyway. On rare occasions I would alloy 14K yellow gold, but
preferred not to.
EPA has made it very difficult to buy chemicals for refining, so the idea of
a home refining operation is now becoming almost impossible. Further,
unless one knows what to do and when to do it, a lot of value can be lost.
The worst thing is that the environment in a refinery has the potential to
be very destructive. Without very good ventilation and fume disposal,
pretty much everything in a room that can corrode does. I kept my fume
hood running almost non-stop and still had minor problems. Refining isn't
something you should include with any other operation.
So now that the value
Absolutely the best advice given. All of it! Virtually all of my
customers did exactly that, so it is an industry wide practice. Some cost
saving steps simply aren't worth the risk. Making solder from used gold is
risking an alloy that won't roll. The quality of gold already in use can
be questionable, especially if it is a soldered item to begin with.
And more. Depends on the color desired, and the sacrificial element used to
keep the properties of gold useable. Each refinery has its own 'secret'
constituent. Each time gold is melted, it tends to lose its ability to be
worked, thus it can not be melted endlessly once alloyed. Smart benchmen
melt only the amount needed, and use the small sprue from one casting in the
following casting,having pickled it well. That way they work with fresh
Green gold is comprised of gold, silver and copper, percentages varied
dependent on the karat fineness. Red gold is copper and gold. White gold
has NO silver, only gold, nickel or palladium. Gold and silver combined
yield green. Go figure!
Some white gold alloys DO have silver in them -- I use an 18kt
palladium white alloy from PM West that is 75% gold, 15% palladium,
and 10% silver. It's a nice, very workable alloy with good white
That one's new for me. In all my years of refining I don't recall every
consciously seeing it, but it could have easily slipped through the cracks
when mixed with old dental alloys and jewelry waste. Dental alloys almost
always have at least a trace of palladium. Palladium in solution is hard
to miss, being very dark in color, like very strong coffee, unlike platinum
or gold. When it's present, there's no mistaking it.
I think what surprises me more than anything is the claim that it works
well. Silver is added in combination with the platinum group metals to
dental alloys to toughen them. They are not known for their malleability,
but palladium and silver combined may not react that way without platinum
present. I know that silver destroys the malleability of platinum.
Very interesting report, Bob, and I thank you. I can only assume that the
presence of the palladium overrides the ability of silver to turn the alloy
green. Regardless, it's always been interesting to me that an alloy that
is predominantly gold can be turned white by the addition of only 25% of
Yep, copper too (look at the nickels in your pocket - 100% nickel they
ain't!). Keeps good color against zinc though, I think it starts turning
white with beta brasses. 15% Zn is still semired...
"I've got more trophies than Wayne Gretsky and the Pope combined!"
- Homer Simpson