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Soldering large sterling loop onto stone pendant


#1

Hello all, I need some help figuring out how to solder a 1/2 inch
diameter 14 gauge sterling silver jump ring closed while the jump
ring is attached through the drilled hole of a stone pendant. I was
told by one jeweler to suspend the stone in water with a 3rd hand,
but this has not worked for me. The water and 3rd hand act as too
large a heat sink and the sterling jump ring never comes up to
temperature.

Any suggestions would be appreciated.
Thanks so much, Ann at Barefootpony


#2

You could try “Heat Shield” but it actually sounds like you are
trying this with too small of a tip on your torch. You need a greater
total number of BTU’s but not a hotter flame. Silver is a great heat
"grabber" so you need a greater number of BTU’s per time period
(bigger flame) but not a hotter one.

John Dach


#3

According to my tables, 14 gauge is just over 2mm, which is a big
lump of silver to solder less than 12mm from a stone that it touches.
You’ll need a lot of heat so that you melt the solder before the
heat has had time to travel through the silver and damage the stone.

You will certainly need to suspend the stone in water, or very wet
sand, and use a flame big enough to raise the temperature quickly. I
use wet sand because it holds the item without the use of a third
hand.

In my experience, Heatshield paste will not protect the stone in this
particular case. It will stop the actual flame from damaging the
stone, but will will do nothing to prevent the heat travelling
through the silver.

Better still, if you have access to a laser or PUK welder the job is
trivial.

Regards, Gary Wooding


#4
You could try "Heat Shield" but it actually sounds like you are
trying this with too small of a tip on your torch. You need a
greater total number of BTU's but not a hotter flame. Silver is a
great heat "grabber" so you need a greater number of BTU's per time
period (bigger flame) but not a hotter one. 

Yes, Ann, you need more heat, and fast. If it takes more than five or
ten seconds, you will be messed up. You can practice by suspending a
similar wire, without the pendant attached. Try to keep very little
of the wire in the water, just enough to submerge the pendant. Heat
Shield instead of water can help with this aspect, because you can
mold it around the work and keep it off of more of the ring. But then
you can’t see what is happening under there! I’d say, more heat,
fast, and practice. If you do not have the torch for this job, don’t
attempt it unless you are prepared to replace the stone if necessary.
Perhaps you can jam some insulating material, like a piece from a
coiled soldering pad, between the wire ring and the top of the hole
in the piece, if there is any room there. That might help.

M’lou Brubaker
Minnesota, USA
http://www.craftswomen.com/M’louBrubaker


#5

I like to use a fiber blanket for shielding stones when soldering
(among other things). It’s made from ceramic fibers and can be
pulled apart like fiberglass batting -OR- cut with scissors to make
a slit to poke a ring shank through -OR- molded (with my fingers)
around a stone/prongs.

I also anneal on one of these blankets. It’s very handy, and when it
gets gunked-up with boric acid flux, I can just pull apart that part
of the blanket and throw it away. The area underneath is fresh and
clean.

Cheap. High temp resistant. Highly recommended.

Small size: http://tinyurl.com/yghjb8k
Large size: http://tinyurl.com/ygavglt


#6

options…

as has been suggested, more heat

Change how you approach the bale. Instead of a single large jump
ring solder two JRs together, flat, one being smaller than the other,
like a headless snowman. The smaller JR should be just large enough
to go thru the hole without binding. Leave this ring unsoldered at
its opening, which you should orient to be just aft of the joint with
the larger, soldered shut JR. A small fat JR can be quite stable if
you work harden it some. This all avoids soldering next to the stone.

I’ll laser it for you if you like.


#7

How about skipping everything and TIG weld the jump ring on.
http://www.lindseyjewelers.com/silverpendant.html


#8

Joining metals with a joint that is in close proximity to a heat
sensitive stone or other item is just the application laser & pulse
arc welders were made for.

If you can, find someone who has a laser or a Puk, ABI or other
brand of pulse arc welder. Generally these tools can fuse the items
together with a very short time without heating the adjoining area.

Dave


#9

Hi,

Don’t know if anyone suggested this but why not take it to a laser
person and get the loop lasered on? Cheap and I don’t think there
will be damage.

Esta Jo Schifter, Phila PA


#10
I like to use a fiber blanket for shielding stones when soldering
(among other things). It's made from ceramic fibers and can be
pulled apart like fiberglass batting -OR- cut with scissors to
make a slit to poke a ring shank through -OR- molded (with my
fingers) around a stone/prongs. 

Unfortunately, none of the heat shields will stop the heat being
conducted through the silver. They just protect the stone from the
direct heat of the flame. If you use conventional soldering methods
without actually cooling the stone, then no matter how fast you melt
the solder, the heat will travel through the silver and damage the
stone.

In this particular case, there are only two ways to protect the
stone: keep it cool by holding a cooling agent (ie water) near it and
using lots of heat to melt the solder quickly, or to use a laser or
PUK welder to fuse the joint in a milli-second or so.

Regards, Gary Wooding


#11

To be a bit contrary - why don’t you use argentium sterling for
this? Argentium doesn’t conduct heat the same way as conventional
sterling. You would need to solder or fuse the ring very fast, but
you shouldn’t damage the stone because it wouldn’t get particularly
warm from metal conduction.

If the stone is valuable, practice the technique first so you see
how different Argentium is to work.

Judy Hoch


#12

You might try cutting a small piece of lead solder, flattening with
a hammer to make it very thin. place in seam of loop and it wont take
much heat to melt it then you could move the joint to the hole of the
stone and it wont be very visible. Many folks do not like lead solder
for many good reasons, but if you use a thin piece and just enough to
fit in the seam it should be barely visible.

Mary
Namaste


#13

Gary,

Unfortunately, none of the heat shields will stop the heat being
conducted through the silver. 

Guess I should have made it clear that the fiber blanket is used
only to prevent the “stone protection” from burning off (previously
mentioned as a problem) via the direct flame. To protect the stone,
I usually wrap the stone/prongs in wet toilet paper. Then use the
fiber blanket to protect the TP from drying out/catching fire from
the torch flame. In other words, the TP protects the stone from
conducted heat and the fiber protects the TP/stone from the flame of
the torch. Hope I beat this dead horse enough :wink:

Jamie


#14

A 2mm jump ring is on the heavy side even as a ring shank. Soldering
a silver ring shank while the stone is submerged in water requires an
oxy-torch. Pulse-arc and lazer will do it without needing to protect
the stone. Tig may be somewhere inbetween…it will put in sufficient
heat either way but the stone may need protecting from conducted
heat. The gas-air torch really needs to heat the whole item in a
complete heat envelope without any heat drain.

I use an oxy-acetylene torch for soldering silver ring shanks while
the stone is submerged in water. If the ring shank is extra thick (eg
1.5mm x 6mm) then the torch must be full blast and hissing with a
2-foot flame accompanied by clouds of steam. Dive in moving fast,
melt, get out. The soldered seam will be porous. I also need at least
1cm of exposed silver either side of the joint while the fragile
stone is at least 3mm under the water for this to be possible.

The above has served me well but every job was undertaken with a
great deal of trepidation and I charge for it (100% success rate
notwithstandin). Now I have a pulse-arc welder and the trepidation is
removed…but I must still charge for it because tough problems
require expensive solutions. If only all the soldering could be done
before setting those fragile stones! That’s why repairers are a breed
apart.

Regards, Alastair


#15

IMHO, do not trust the “soft” solder to hold anything, and, do not
introduce “contaminates” into the silver, you are asking for trouble.
Be creative. Or, set it aside on the bench and let it “be” for a
bit… you might surprise yourself!

PS: The lead joint will always be visible.