I must be getting too old for this

Recently, I have noticed a lot of difficulty in sizing commercially
made rings. These rings are not “cheap”. They are of a relatively
heavy nature, set with a healthy weight and quality of diamonds.

The difficulty comes when trying to solder them. They seem to form
an invisible coating of oxides much as do stainless steel or
aluminum. Solder flow is difficult. The metal has a large grain and
the boundaries tend to separate thus requiring more solder which
doesn’t seem to flow. Lastly, these items appear to have been cast.
More or cleaner flux has no effect.

I suspect that these rings were cast in some of the new “deox”
alloys.

I don’t have these problems with my own alloys. I have only noticed
these problems in new commercially made goods only and I am rapidly
becoming disgusted with the idea of continuing commerce as a trade
shop.

Have any of you all had experience with this?

Bruce D. Holmgrain
JA Certified Master Bench Jeweler
http://www.goldwerx.com

Hi Bruce; You don’t mention if these are silver or gold rings, but
I’ll assume they’re gold, as it’s unusual to find silver set with
quality diamonds. Are these white gold settings? I’ve found that
the pervasive rhodium plating on the white articles interferes with
soldering, and I get to kick myself when I forget to sand it off
before soldering and find myself chasing pits away from sizing seams.
I have more problems with 10K too, and would be glad for
suggestions. I solder with non-cadmium 14K plumb solders from
Stuller, and use 19K white weld for white gold ring sizings. I’ve
also switched to a self pickling flux without fluorides, and between
leaving the cadmium and the fluorides behind, I’m getting more
occasions to struggle with solder not flowing, so I’m at a loss as to
what factor is the larger contributor to the problem. It’s cold
comfort to know there’s another old veteran having these problems.
:slight_smile: Hang in there, I’d bet there’s something here we can discover.
As for leaving trade work behind, well, there are plenty of reasons
for that, but hey, for now, it’s a living.

David L. Huffman

Hi Bruce, I have also noticed some materials as you describe and not
getting as smooth a flow as usual. With these rings I need to "pull"
the solder to the inside (with heat) more than usual to be assured of
a good flow through the joint.

I use a watered down flux when I solder and a very hot flame. I
don’t care for the caked on effect and the bubbling of the flux at
full strength. (I use the green stuff). As a result I get a much
lighter coating of flux around the joint, and I get a better feel for
the temperature of the metal by color. For me this method has me
heating the ring for a shorter period of time so less oxidation can
form particularly at the joint. (I hit them hard and give it the
solder the second the ring is up to temp)

Once I get a flow on the outside of the ring I hold it up with a
tweezers and immediately get the heat on the inside of the ring to
pull the solder through the rest of the joint…This also helps
eliminate porosity from the solder on the outside surface.

I then quench it hot…(controversial I know)…before the heat can
travel to the top side of the ring. This allows me to work on most
rings, even with color, without heat sinking them except for getting
them wet. (There are exceptions & I don’t advise this to any of the
readers unless they are experienced)

I have found if I don’t get a good flow and the piece gets oxidation
the best bet is to stop…pickle it…hit it with a saw blade to
clean up the joint if needed…and try again. Attempting to force the
flow will not work.

Regards, Mark

Ps For the novices out there…Very hot flames are dangerous to your
jewelry if you are not used to it. Learn the heated colors of the
metals you use and their melt points. Solder always flows towards the
heat. Heat the piece and it will take the solder from your pick when
it is up to temp. Always heat sink stones while learning.

They may not solder well, but they fuse nicely!

I gave up on working on silicon based alloys years ago. I really
don’t enjoy working with them! I remember that at one time someone
was working on an alloy that included grain refiners along with the
silicon. This was a definite help, but it was only experimental and
was unfortunately discontinued. Have you tried using silver paste
flux instead of the cleaning flux? It’s messy but seems to help.

Jeffrey Everett

Hi Bruce, I have experienced many of the same problems you mentioned,
particularly in new, “discounted” pieces coming from the discount
retailers (i.e. Kmart, Walmart, etc.), and I am no longer taking them
in for sizing. My sales staff has been instructed to send these
customers back to where they purchased the items, even though it may
take weeks for a sizing turnaround. I, too, thought it was my
advanced years and general irritability at not making the sales
myself.

Jon Michael Fuja

Hi Bruce,You are probably working on alloys containing silicon. The
silicon when heated forms a silicon dioxide layer on the surfaces of
the metal and is resistant to wetting by the solder. A paste flux
containing fluorides may help in dissolving the silicon dioxide and
allowing the wetting of the metal. Silicon is often used in lower
karat (14-9K) cast gold alloys to act as a de-oxidizer and to
increase fluidity of the molten metal. It is not typically used in
rolling alloy or in higher karat alloys. Silicon makes some alloys
easier to cast but it sucks if you have to solder alloys that have
high silicon content.

Jim

   You are probably working on alloys containing silicon. The
silicon when heated forms a silicon dioxide layer on the surfaces
of the metal and is resistant to wetting by the solder 

Hi Jim and Bruce;

WOW! Now it all makes sense. Thanks Jim. I had suspected silicon,
but not knowing the chemistry, I ruled it out, figuring that the
silicon burned off during the casting process. Years ago, I used to
use a silicon containing gold alloy and I don’t remember having
problems, but of course, back then, we used cadmium bearing solders
and flouride fluxes without concern. I suspect too that it’s often a
matter of degrees, as in 14K not so much a problem . . . 10K more
problematic. Seems you may have answered both my question and
Bruces. Guess I’ll just have to resort to the old flux when I seem
to be having problems.

David L. Huffman

Jeff,

  They may not solder well, but they fuse nicely! 

In fact, the really weird part is that this last ring didn’t even
want to fuse. The metal would melt like aluminum around the slice or
crack where I was working, but wouldn’t close as if it was full of
rouge or some other contaminant.

   I gave up on working on silicon based alloys years ago 

I am opening up a retail location on the 25th of this month. I’m
running very scared at the moment and don’t want top give up any work
right now. Trade work has been crappy in recent years, but I think I
have reached my limits.

David,

   You don't mention if these are silver or gold rings 

These are yellow gold rings. I have been running into this more and
more. I assumed that I had dirty fingers for a while and was getting
rouge into the joints or something. That’s the way that these rings
are behaving

I had a client that was selling weird platinum alloys a couple of
years ago and I was running into some of these same types of
problems. Strange oxides or other contaminants and lower melting
points. I no longer do these peoples work so it is not presently an
issue.

I also avoid cobalt alloys whenever possible.

Mark,

We share a number of methods. I see nothing controversial about
quenching a ring sizing while hot. I was taught to hold the ring in
my fingers to avoid overheating the stone. As for flux, I’ve been
trying more and less flux. Batterns seem to have no effect.

Jon,

    I have experienced many of the same problems you mentioned,
particularly in new, "discounted" pieces coming from the discount
retailers (i.e. Kmart, Walmart, etc.), and I am no longer taking
them in for sizing. 

That’s a good thing to hear. In my new shop, I will have to develop
a policy pretty quickly.

Jim,

   You are probably working on alloys containing silicon. The
silicon when heated forms a silicon dioxide layer on the surfaces
of the metal and is resistant to wetting by the solder. 

This sounds right. It is a good description of what is happening. I
have been using Batterns flux, which I understood to contain florides
… ooops! I just took a look at my bottle of Batterns only to
discover that my Batterns is in fact Griffiths floride free flux.
This may be key to my solution. I’ll quick get some real flux. I
wasn’t avoiding florides in flux from a fear of HF as some may. It
was just ah … sloth … I’ll have to take care to read the bottle
next time that I make a purchase. If it doesn’t work better, I’m
afraid I’ll be telling people where to cram their junk jewelry.

Tanx all

Bruce D. Holmgrain
JA Certified Master Bench Jeweler
http://www.goldwerx.com

David, If it is 10K of recent manufacture then your problem is most
likely silicon in the alloy. Try paste flux with fluorides in it to
help with the wetting of the metal. Jim

    David, If it is 10K of recent manufacture then your problem is
most likely silicon in the alloy. Try paste flux with fluorides in
it to help with the wetting of the metal. Jim 

Hi Jim;

Yep, tried that and it does seem to get better results. I did want
to stay away from the flourides though. I don’t want to expose my
employees to the health hazzards I unknowingly lived with for all
these years.

David L. Huffman

    ... ooops! I just took a look at my bottle of Batterns only to
discover that my Batterns is in fact Griffiths floride free flux. 

Hi Bruce; That’s what I switched to from Batterns. I’ll bet that’s a
contributor to the problem, since it seems the problem for me started
at that time. Have you noticed that the Griffiths seems to form a
dirty looking foam as it melts? I still suspect the silicon though.
Been a bit discouraging for my apprentice, as I’ve seen him having
the same problem you describe in melting the area before the solder
flows. I’ve had to work to convince him it wasn’t something he was
doing wrong, since about half the time I take one that’s gotten away
from him and get it to work. But then, I’m a bit slicker with a
torch. He’ll be relieved to know I wasn’t just trying to make
excuses for him.

David L. Huffman

I stopped using solder when sizing about 10 years ago. If sizing
down, I take the piece I cut out of the shank and use it to melt the
joint together. I very rarely get any pits, and no solder seam. If
going up I try to find a bit of scrap that looks compatible and do
the same thing. By focusing the heat on the piece I’m adding and not
on the shank, the molten piece flows into the joint. I save a lot on
solder this way as well! This is a technique that requires some
torch experience.

Spike Cornelius
Portland, Or.
RC ArtMetal

David, I am glad the flux helped some. You might also try the
"Black" paste flux. It is a boron modified flux used for soldering
metals that have tough oxides like the chromium in stainless steel.
BTW if your soldering stations are properly ventilated there should
be no inhalation of the flux vapors even with the more active
fluxes. We have built what amounts to a fume hood at each soldering
station to keep the fumes from being inhaled. If you would like I
can send a picture of it to you.

Jim

Replaced my flux with fluoride containing paste today. Seems to have
gone a long way toward treating the apparent “too much silicon in the
gold” problem, and I want to thank you all for bringing to my
attention the fact that I was using an ineffective flux.

Bruce D. Holmgrain
JA Certified Master Bench Jeweler
http://www.goldwerx.com