Needs help with Red Gold

I cannot believe I have two problems in one month…Someone who
has worked with red gold needs to educate me…

Customer came in and had a very old pink (red) gold wedding band
with inscriptions on the inside (about 5mm half round) another
local goldsmith sized it up for her , added a yellow gold shank
for three sizes up…OK so I cut out the yellow gold shank…I had
some old red gold bands in a drawer I kept for this very
deal…and behold…crumble… the red gold seems to crumble when
I attempt to weld it…I have a hard red Hoover and Strong plumb
solder…Not my stuff the cusatomer ring…Do I go to an easy
solder… her ring is probably not 14K …could even be 10K or
9K… I attempted to anneal it…didnt seem to help…Next step
…ask for help… never to old to learn…

Terry Parresol

Hello Terry, When you heat red gold you must quench it quickly,.
If you allow it to cool slowly, this metal will become quite
brittle. Hoover and Strong sells a 10k pink gold solder that is a
pleasure to work with. Have fun. Tom Arnold

Oh God! I sympathize with you. I have run into the same thing.
Antique pieces can be a pain! My solution - be it imperfect -
is to solder in the new piece with low temp solder and fill in
the pits best possible. I have found a very good device for
removing pits caused eather by bad soldering or casting. It is
a simple mounted wheel of about 3/4" and fits in your handpiece.
It’s shape simply burnishes over the pitting and, with a little
emerying, the pits are gone!!! Got mine form A local supplier
and don’t know the name of the mfg. but if interested, I’ll try
to find it.

Cheers!
Steve

I cannot believe I have two problems in one month..Someone who
has worked with red gold needs to educate me..

Red gold (especially old red gold) is always problematic.
Hoover’s red gold solder used to have an extremely high melting
point and I always had a problem soldering anything with it.
Their new red gold solder works better but it still requires a
higher temp to work with than some red golds can take. I think
you are going to have to tell the customer that while you can
come close to matching the color of the gold in her ring she is
going to see the joins. If you get a really really clean and
well formed join you might be able to burnish the metal over it
a little and then it wouln’t be so noticeable but I think you
just have to prepare the customer for the worst. If it comes out
better than you say it will they can only be happy.

    When you heat red gold you must quench it quickly,. If you
allow it to cool slowly, this metal will become quite brittle. 

Does that mean that mixing white gold and red gold in one piece
would be a no can do, or is there a work around?

Thanks,

Kat Tanaka
@Katherine_Tanaka

I have found that the rose gold solders from Swest, 11090 N
Stemmons Frw, PO Box 59389, Dallas TX 75229-1389 Phone
800-527-5057 Fax 900-441-5162 are better suited to old rose golds
than the solders from Hoover & Strong. I have not used Hoover’s
new product however. The high copper content seems to make this
allow somewhat problematic. If all else fails there are fair to
good color matches available in contemporary alloys, by
carefully heating the contemporary alloy which has been "tinned"
with a matching color solder and to a slightly lessor degree the
unknown allow a suitable joint can be made. I must point out
that this is an inherently bad soldering technique but in some
extreme cases it seems to be the only way. I have encountered old
rose alloys which melt and flow before any solder I could find,
and by using this poor technique with out solder I could achieve
a strong joint.

WayneM

Dear Red gold sufferers, I concur with the litany of described
rose-gold related problems. I’ve found that Hauser and Miller’s
rose-gold solder is about the best. Rose-gold solders do not
flow without pitting. An extremely generous clipping of solder
must be sandwiched between the pieces that are to be joined. Heat
up and melt all the solder with a fairly hot, large flame at one
time, as best possible. Then (groan) file away all that extra
fill. If you run into a pit, begin burnishing as soon as they
become apparent. You can usually salvage the"seam". Rose-gold
solders do not re-melt well. It is sort of a “one shot deal”. I
must agree about discussing the seam color-variation with your
client before you attempt anything.
Just what works for me, Eben

   Does that mean that mixing white gold and red gold in one
piece would be a no can do, or is there a work around? 

The work around is to use a pink alloy, which is a high copper
rose color, but still has a little silver. the main problem is
with gold/copper alloys with nothing else. The worst offender is
the 18K alloy of just gold and copper, which if cooled slowly
enough through about 800 degrees F (don’t recall exactly. Have to
check the phase diagram, which is “somewhere…”. can form
what’s called an ordered array structure, of alternating layers
of gold and copper atoms. That structure is very brittle. In
14K, it’s less of a problem, but islands of that structure can
still form if a 14K gold/copper alloy are slowly cooled, since it
can differentiate out as the metal cools slowely enough. Once
formed, it takes a thorough annealing temp to again randomize
the atomic structure, and quenching hot enough to prevent it’s
reoccurance, a process the white golds won’t much like. But you
don’t quite have to quench it from a red heat. Just a hair
below, around 900, will do the job, and most white golds will
usually survive that. Easiest, though is simply to use a rose
gold alloy from a decent commercial source that is not just gold
and copper. You can still get a nice rose color without having
to have it all copper and gold. Your metals supplier can advise
you on the best alloys to use for your purposes.

Peter Rowe

My thanks to all who replied with certainly good nformation…I
surmised the old red band could not take the heat of the Hoover
hard solder… so I had some soft red overnighted and proceeded
to roll it out very thin so it would melt quicker…soldered the
shank material into the old red band and burnished …and
burnished…and color looks good… asked my now new customer to
stop by in a month so I could have a look see how the color holds
up… I appreciate the good info… Terry Parresol in Central
Florida