Normally, I wouldn’t bother with this. But I have a faithful customer
and friend who has asked if I can repair a bracelet that was given to
her as a gift - it’s meaningful to her, etc. The problem is that it
is basically “costume” jewelry, made of some kind of cast white metal
if that’s the right term. It appears to be some kind of
pewter/zinc/tin/bismuth/I-don’t-know-what. It was broken while in a
handbag which was slammed in a car door. There is a jagged, clean
break in the metal. The best solution (aesthetically) would be to
solder it, if that is even possible. After that, I will have to
consider some form of cold connection, which will require altering
the design of the piece. My two questions are:
Any clues as to how I might identify the composition of the
metal? It’s a dull gray metal, very light. The break does not have
that granular, crystalline texture that you might see in a broken
die-cast toy. It looks very much like lead pewter, but it lighter,
harder, and does not streak when rubbed on paper.
Can this stuff be soldered? I’m sure it’s a very low melting
temp.
Thanks so much for any and all advice you have to share.
David- It is indeed a very low temp metal. You can melt this stuff
with a lighter. The only way to fix it would be to use lead solder
or glue. I’ve always used Tix soft solder for costume repairs.
Costume jewelry repair can be a challenge.
If its unsolderable you might be able to construct and hide a
’splint’ on the backside and cement or rivet it in place. Make sure
its big enough to distribute the stress of however it is used.
You might be able to solder it with low temp lead free solder, and
you might not. If you do there is a good chance it won’t hold. The
alloy would be some proprietary formula and it’s unlikely you can
learn what it is, but even if you do, what good does the knowledge
do you? What you need to know is the melting temperature. Depending
on the design, you may be able to give it added strength by backing
the joint with a sterling strip. When confronted with this situation
I simply explain the problem to the owner, telling her that it may be
a somewhat iffy fix and it’s possible it may be damaged worse in the
repair attempt than it is. I also point out that the item is useless
as it is anyway. Usually they want me to give it a try
Early in my career I made white metal models from a tin alloy. (Can
be purchased from Contenti). I welded the metal using a copper headed
soldering iron that was tinned and heated over a Bunsen burner. If
the metal is a tin casting alloy it could be welded at low
temperature. I also soldered the alloy, a very delicate task
considering that the solder flow temperature was a few 10s of degrees
below the melting point of the tin alloy.
David - I’m sure you’ll receive a lot of cautionary tales besides
mine, but my advice is to avoid using heat on an unknown metal. I did
a repair on a piece from a major “party retailer” which was stamped
.925 - the instant I touched flame to it, it vaporized. It was a
porous gray mystery metal underneath the shiny surface. Luckily it
vaporized beneath a hinge, and I was able to pop the hinge pin out
and recreate the missing piece from sterling, but if it hadn’t, the
piece would have been trash. Is there any way you can unattach the
broken piece, so in case it reacts in an unexpected manner to heat,
you won’t have wrecked the whole piece? Or repair it without heat?
I just read this post and have faced this issue many times in
repair… Sometimes I can use a low,low base solder–say Stay Brite
and have success… But only for awhile since it’s patch & this is
basically what I call “base metal”…It may break again.
Onetime I had a very sentimental costume necklace that was broken on
the linkage,not wearable as it was and was taking Jim Binnion’s Puk
Welding class down at Revere Academy…He & the sales rep. for the
welder unit did a weld with the Puk II, it held and all were
happy…I might mention that this was for a justice’s daughter on The
Supreme Court and she was told we’d try our best but no liability on
the work…Just that we’d do our best & handle with care…To this
day, I believe the repair worked…But no idea if the rest of it,
anywhere else along the necklace, held up… You could also check with
those who do laser repairs & understand how it would work on this
piece.
Like it’s been stated, there really is nothing to loose if it
doesn’t work- the piece is already broken )-:
Cheers from very foggy San Francisco, home of the coldest summer-
Sincerely offering free samples of fog,
I missed the original post that started this thread, but I often am
asked to do white metal repair, using the laser.
I have found that Stay-brite soft solder works best for me. I step
the voltage on the laser down as low as it will go (@150v), bring
the length of the pulse up to 7 or 8 ms, and work in high speed
bursts. I also have found that using the liquid flux that comes with
the Stay-brite solder is quite effective. This is the only operation
on a laser where I use any flux.
I first tried this several years ago, as an experiment, on "pewter"
belt buckles, with some success, and I have now used it many times
to rebuild costume jewelery. At joints it is best to replace the
white metal “wires” with SS wire, if possible.
Onetime I had a very sentimental costume necklace that was broken
on the linkage,not wearable as it was and was taking Jim Binnion's
Puk Welding class down at Revere Academy..He & the sales rep. for
the welder unit did a weld with the Puk II, it held and all were
happy..I might mention that this was for a justice's daughter on
The Supreme Court and she was told we'd try our best but no
liability on the work...
I forgot about that repair. I don’t normally do repairs on other
peoples work so that was the only time I ever used the PUK on white
metal. But a PUK might be a way to do it.
The white metal castings you speak of can be repaired. I have
successfully soldered them together, but it is tricky. You need to
order in some Tix solder and Tix flux. This solder melts at about 450
degrees, so it doesn’t take much heat at all. I barley give my torch
any oxygen at all to keep the flame very low temp. You may want to go
to a goodwill store or thrift shop and pick up an old piece to
practice on. If the break is not clean you will have a problem. You
can not fill gaps or holes very well with Tix solder, and it is a
slightly different color. It is hard to polish ( I usually don’t
polish) it at all. If done with a low temp torch and patiently, I can
solder right next to rhinestones and other costume stuff, and just
wash in water when done. I never file or sand the solder. Yes the
solder lump is visible, but that is the best I will do. I just tell
the customer in advance so they know what to expect.
I keep a separate soldering board just for this low temp stuff, I
don’t want it on my high temp boards.