Back to Ganoksin | FAQ | Contact

Solder repair


#1

Hello!

I am in need of some advice for a solder repair that I am doing. I
have a sterling silver ring with a bezel set turquoise stone. The
shank has split and needs to be soldered. The bezel is so tightly
set around the stone that I will ruin the bezel and the turquoise
trying to get it out. I showed it to one of my local suppliers and
he advised me to put the ring in a small crucible with water
covering the part of the ring so the turquoise is protected. I did
this and attempted to make the repair, but for the life of me cannot
get the solder to flow properly. I would appreciate any tips or
advice anyone can offer.

Thanks in advance,
Erica


#2
he advised me to put the ring in a small crucible with water
covering the part of the ring so the turquoise is protected. 

Yup. That’s right. though you don’t need a crucible. I use the type
of shallow/wide tin can cat food or tuna fish comes in. The water
keeps the can cool too. While the water may well reach boiling
temperature, that’s safe for the turquoise, and the water cannot get
hotter than that. Physics and all that jazz y’know…

I did this and attempted to make the repair, but for the life of
me cannot get the solder to flow properly. 

That’s the other side of the coin. Silver is an extremely good
conductor of heat, and that can of water is not only cooling the
turqoise, but it’s pulling the heat right out of the silver shank.

You need to be sure that not more of the ring is under water than is
needed. the bezel needs to be covered, and the stone, but not further
up the shank than that if possible.

And then you need a really hot flame. This will seem insanely hot
compared to what should be needed for that solder joint. The flame I
use, from my meco midget torch with oxygen and propane, would easily
melt a fairly good sized chunk of platinum, were it not for the water
cooling the silver. You may also need to have something over the
surface of the water, under that seam, to protect the seam area from
spatters of water boiling off where the shank enters the water.

That spitting stuff can blow out your torch flame if it hits right.
And for the same reason, eye protection. You may need some sort of
dark glasses with that hot flame to be able to clearly see when the
solder flows. You CAN get it to flow if your flame is hot enough, but
what you’re needing to do is pump heat into the silver faster than
the water can pull it out. That ends up being a fine and dramatic
demo of just how good a thermal conductor silver really is.

I should mention that if you have a smaller or cooler torch, such as
an air acetylene torch or a butane torch, etc, you may not be able to
get the metal hot enough. You need an oxygen/fuel type torch of some
sort. And a “Little Torch” also may not be able to do it with
anything other than a fairly narrow or thin shank, even with a large
#7 tip.

You may also wish to use an easy, or at most medium, grade of solder
rather than hard, which you might have used to initially make the
ring.

And of course, you have another option. That would be to find
someone with a laser welder of a pulse arc type welder like an Orion
or PUK welder. These can weld up the seam in your ring without danger
to the turqoise. If you cannot get the solder to flow with the torch
you have, despite cranking it up all the way, then finding someone
with a laser or pulse arc welder would be the easy fix.

They’re a lot more common now than they used to be.

Peter Rowe


#3

Reading this with the reference to eye protection caused me to
wonder, does one need ultra-violet protection when soldering ? I
never thought of this before.

Mike
Mike Brenner


#4

I put items that need to remain cool in water all the time. I always
hold them with stainless steel cross-lock tweezers that I use as a
heat sink. Maybe they stop the heat sinking from going into the
water? I don’t know but it is always successful.

Esta Jo
shiftingmetal.com


#5

Hi Mike, that’s a good question you pose, and one I have recently
been considering. I have looked through the archives and not seen
anything that would answer this question (or maybe I asked the wrong
search terms?) I have been working a lot of steel recently and get
it orange to yellow hot and find I’m seeing yellow afterwords. This
can’t be a good thing.

I picked up some green glasses at the welder’s supply, but I really
can’t see the subtle color changes I need to. Anyone want to suggest
eye protection and the types available for our use? TIA,

Susan Ronan
Coronado, CA


#6

Only when soldering platinum using platinum solders. Then you need a
weldersprotective lens

Vernon Wilson


#7
Reading this with the reference to eye protection caused me to
wonder, does one need ultra-violet protection when soldering ? I
never thought of this before. 

not generally with torch work. Higher temperatures, like platinum
work, need protection against heat (infrared) and simply intense
glare. With some flames, there might be some UV at those temps too,
but if your eyewear is dark enough to let you work with platinum,
likely it’s also blocking U. V. (one exception is a type of dark blue
glass that used to be used sometimes for platinum work. Fine for
melting furnaces that can melt platinum, but not so fine for torch
work, because of the possibility of U. V. Where you really do need UV
protection is with any electric arc, which for jewelers includes
pulse arc welders like the PUK or Orion. Also, to a much lesser
degree, things like sparkie welders do produce a little UV, but
probably not enough to worry about, especially if you’re using any
minimal eye protection, as you should just against things like
spatter…


#8

re UV from soldering - short version - no.

The relative intensity of radiation from solder is determined by the
emissivity of the material (which frequencies it likes to radiate)
and it’s black body radiation - see the wikipedia link below - as you
can see even at 5000oK the majority of the light is in the visible
part of the spectrum.

Plasma arcs on the other hand are both very hot and have UV line
emission spectra on top of the black body radiation…