I just had something very unexpected happen while soldering a fine
silver bezel to a sheet of sterling. The sterling was 20g and was run
thru the rolling mill once, very lightly impressing a fabric pattern
on it.
I then put the bezel, flux and solder on the sterling sheet. I
mounted the sheet on two enameling trivets so I could get the torch
underneath the sheet and heat it from the underside. The trivets
weren’t the best approach but that’s beside the point.
I applied a light pressure on the bezel wire with a soldering pick
so the bezel would maintain contact with the sheet.
As the sheet got hot it sagged a bit and shifted the bezel, hence my
comment about the trivets not being the best way to do this. (Oh! The
joys of learning.)
Here’s the surprising part. One of the corners of the sterling sheet
detached itself from the rest of the sheet. The metal along the
broken edge looks like it crumbled off (as opposed to was sheared
off).
Huh? What is going on here? Is it bad metal? Or did I just do
something stupid that I don’t understand?
One of the corners of the sterling sheet detached itself from the
rest of the sheet. The metal along the broken edge looks like it
crumbled off (as opposed to was sheared off).
This sounds like you’re working with Argentium Silver. It breaks if
nudgedwhen it’s still hot.
Huh? What is going on here? Is it bad metal? Or did I just do
something stupid that I don't understand?
It is later and not the former.
First problem is in using soldering pick. Soldering pick must be
reserved for professionals.
In skilled hands it improves speed. Beginners must learn how to
solder with paillons.
Second problem that I see is the gap between parts. There must be
none.
Third is attempt to apply pressure during soldering. No mater how
light, it is destructive. Once again, some pros using it with great
success, but it is not for beginners. It takes years to learn how to
apply pressure during soldering and even than it is risky.
Fourth is using 2 trivets instead of one. It is impossible to align
two trivets in single plane, which may the reason for the gap between
parts.
Fifth is that you did not anneal after rolling and it is not a good
idea to flush-solder on textured surface. More thought should be put
into methods of joining and solder application.
Usually when sterling breaks with a crumbled edge it is because of
quenching when too hot, or it could also be a bad alloy.
You said that you were soldering a bezel onto flat sheet and I
wondered if you have ever seen or used clamps to hold the bezel in
place. I make my own soldering clamps from G20 Stainless steel sheet
and they are great for holding bezels in place while soldering, they
are not difficult to make, I just pierce a strip from a sheet of SS
about 100mm. x 3 or 4mm. and bend to shape with pliers, each clamp
takes me about 4 minutes to make. I would also advise that you
support your soldering pieces on a firebrick when soldering, rather
than enamelling trivets. I prepared the attached photo of my
soldering clamps for another forum, perhaps Hanuman will kindly post
it on here for all to see.
Couple of things - is the sterling Argentium or plain ole sterling?
Once in a while, you will get a bad batch of silver that breaks.
I’ve hadbad solder, bad 10g. round wire that kept splitting, no
matter how careful I was, and some old silver sheet.
Sounds like the trivet did not provide support, and when you were
heating the sheet and applying gentle pressure, it was too much for
the sheet metal. I found if I don’t support my sheet metal, the
corners start drooping.
You’ll need to find a charcoal block or a screen to do your bezels
in the future to avoid breakages. Also, after I roller-print my
sheet metal and flatten them, I have to anneal the sheet, before I
put my bezel on, otherwise, the sheet warps from the uneven
stresses. You may also havebad silver sheet. Buy a fresh piece of
silver sheet metal and get a screen and try again on your bezel.
Another tip, if you can get 26g. fine silver bezel strip, use that.
Avoid 30g. bezel strip and use 28g. if you have to, but 26g. bezel
strip isbest, and even thicker if possible.
Joy (who has done one too many bezels, thousands of them by now)
I would use a screen to support that 20ga sterling piece. I have a
tripod which allows you to get the torch underneath, but anyway you
support the screen would work. The silver will sag when heated,
especially if you are applying any pressure to the bezel.
Not sure about the corner crumbling, but I would suspect that edge
was overheated, not supported, or stressed in some way from it’s
trip through the rolling mill, or any combination of the above.
Just to add to the comments about the sterling silver crumbling at
soldering (brazing) temperatures.
This may be a hot shortness that has occurred due to the use of
phosphorous as a deoxidant during the casting process. When sterling
silver sheet or wire is commercially cast, oxygen is prevented from
entering the molten metal by a gas and/or charcoal cover. In
addition the molten sterling silver alloy can be deoxidised by
plunging carbon (graphite) rods into the molten metal prior to
casting or making an addition of an element such as phosphorous
(usually in the form of a copper-phosphorus alloy) which scavenges
the oxygen present in the molten sterling silver alloy. If an excess
of phosphorous is added any residual copper-phosphorous forms a low
melting point phase at the grain boundaries of the sterling silver.
This can result in the hot-shortness (a cracking/crumbling effect at
elevated temperatures) which you describe.
Are you using Argentium sterling silver or other low tarnish silver?
Some ofthese will collapse when heated and need to be supported. I
switched to Argentium sterling 3 years ago, like it very much, but
handle it differently that regular sterling during soldering due to
this property. This also affects your approach with binding wires
and clips–you need to be aware that it will collapse with too much
pressure.
Here is one for the newbies EXPENSIVE quality earrings DO NOT COME
AS CLIP ONS.
Perhaps true today, but back in the sone age when I started, upper
class WASP American ladies did NOT pierce their ears. I still have
some very fancy 18kt clips from then. Larger earrings were in style
then.
Sometimes we had to make hidden hooks to go behind the ear to keep
the biggest ones on.
Here is one for the newbies EXPENSIVE quality earrings DO NOT COME
AS CLIP ONS. Perhaps true today, but back in the sone age when I
started, upper class WASP American ladies did NOT pierce their
ears. I still have some very fancy 18kt clips from then. Larger
earrings were in style then.
I too have several customers (most of them advancing in age) that
will spend thousands on earrings for non-pierced lobes, insisting
that quality earrings, even heavy ones, should need no posts. Posts
and backs on earrings can be and sometimes still are considered by
some to be a short cut taken by inexperienced and less-skilled
goldsmiths. I don’t necessarily agree with that, but if they got the
money, I’m happy to make 'em however they want 'em. And done right,
they’ll stay put too.
Aunt Dot had her name crossed out of the family bible for, shock
horror, marrying a Catholic.
At least he wasn’t a Carlton supporter LOL AFL football team.
I have a video on Nazi goldsmiths, given to me buy a history teacher
let’s just say the SS are not his favourite people. The company
still exists. The point is there is a shot of making pierced
earrings, if my limited computer skills let me I will post the shot,
don’t hold your breathe, I am a computer clutz.
insisting that quality earrings, even heavy ones, should need no
posts. Posts and backs on earrings can be and sometimes still are
considered by some to be a short cut taken by inexperienced and
less-skilled goldsmiths.
I remember my first day in Tiffany. Goldsmith next to me was working
on clip earrings.
He spent whole day just on adjusting the mechanism, so it would
close on earlobelobe firmly but painlessly. The last thing you want
for a clip to snap like a mousetrap. Not a good idea!
Symbolism of pierced flesh is lost on the society nowadays, but some
still pay attention to it.
That is why not all women pierce their ears, or other parts of the
body. Another thing is that sometime design requires earrings to be
in certain fixed position in relation to earlobe. Post cannot
guaranty that, but properly constructed clip can.
Another thing about clips and especially large ones, they must be
light. There is a limit of what mechanism can handle, no matter how
sophisticated. So they are fabricated from minimal gage and all extra
metal is removed. It takes time and special care, so price reflects
it.