Soldering goldfilled

I’ve worked primarily in sterling (and took a 1 week class working
in 14k gold a couple of years ago, but have not continued to work
with it) – and now I want to integrate some goldfill with my
sterling. When soldering, anything I need to keep in mind to combine
the metals?

Another artist has told me that there is the possibility of ‘burning
off the gold’ and having the brass core show if my torch heat is not
right? (I know that can happen with gold plated items, but didn’t
know if that’s the case with the thicker amount of gold in filled
wire.) Tips? Pointers? Suggestions?

Thanks!
Lil

Since no one else has jumped in yet, I will offer what I know.

There are two (at least) major problems here.

If you overheat gold filled, the gold will melt/diffuse/alloy (not
sure technically which) into the brass and then you have just
expensive brass.

It you solder brass (with or without gold) to silver, especially
assuming it is single-clad gold filled, it is very easy to overheat
that combo. As I understand it, brass=copper+zinc. Silver
solder=silver+copper+zinc. So it is very easy to turn your
sterling+brass into a puddle of solder. I’m here to say, I’ve done it
on a number of occasions, because I don’t generally use brass so I
tend to forget. The brass will “collapse” into this puddle, usually
tipping rakishly in the process.

So, can it be done? yes. Are you likely to screw it up until you
figure it out? I’d say so.

I’ve been much happier using gold/silver bimetal to applique
lower-cost gold onto pieces. Lower-cost than solid sheet, that is. I
get 22 karat/sterling bimetal from Reactive Metals, though I believe
Hauser & Miller also has it. It costs a good deal more than sterling,
but you are soldering sterling to sterling; there is no issue with
hallmarking, as your piece is all gold and silver; and the 22k
contrasts beautifully with sterling, whereas 14k is pale and
anemic-looking. It hardly shows up at all. And it is harder to screw
up 22k than 14k because it has a much higher melting point.

Noel

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I’d love to try the bimetals; do you know of any workshops or good
books on the subject? Or is it just not that complicated?

And what do you stamp your 22K and silver? Just silver or 22K?

Barbara

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And what do you stamp your 22K and silver? Just silver or 22K? 

The volontary Australian standard allows us to stamp each component
with a stamp, however where this is not practical stamps can be
arranged according to the greater quantity of metal.

If you have a 18k gold diamond solitaire with a platinum setting,
you can stamp use two stamps the first being 750 gold with the
appropriate gold symbol, then following the platinum symbol stamp
with the platinum parts per thousand there in.

If you wanted to make a mokume gane ring, the same rules seem to
apply, and anything that is not a precious metal simply has its
chemical symbol.

Regards Charles A.

hoover and strong sells gold coloured silver solder- it’s the best
bet but it has to be a hit-and-run solder operation- very fast use
plenty of flux on both pieces/ends and use a butane torch as opposed
to something like a hoke or mecco midget, etc. the flame is more
controlable on a small torch - though it still gets to 2400
fharenheit so don’t be misled into thinking it’s not as hot- just
heat the pieces and wait for the flux to indicate soldering temp then
just do it.you can melt the gold off because it’s so thin, it’s
actually absorbed into the brass alloy…if i were going to use small
bits as accents etc, i’d cough up the money for 10-12 karat at least
if colour is what you’re after…or buy some 24 karat casting grain
and alloy your own material as you can get more out of 5 dwt’s of
casting grain and add fine silver, copper if you need it or whatever
kind of gold it is you want in very small lengths or pieces of
sheet…gold filled is really only good when connecting it to itself
end-to-end as for a bezel, or bangle or inlay as long as you coat the
end with plumb gold solder to seal the core- another thing about gf
is that some is single sided gold bonded to only one side) avoid that
junk unless you are slumping it to something else (use silver solder
under the decoration) and again run plumb gold solder around the
edges to seal them or eventually the core will turn
/corrode…rer

When ever I used gold/filled I always used 14k goldfilled never 10K
G/F and always used 3 to 6 karat yellow repair solder. However, if
you choose 10K G/F you can still use 3K to 6K repair solder with no
problem, just take care and controll your temperature and keep the
flame a bit on the reducing side. Never had a problem with the
melt/flow range of the solder in use with gold filled metals. Then
you can feel as though you are maintaining the integrity of the
metal, and have a slighly better color match.

James F. Conley