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Quenching to Harden Ear Posts


#1

I read this article today (partly quoted below). The advice is about
quenching silver from hot in order to retain work-hardening. Here’s
where I question it. This goes against what I know is standard
annealling behaviour - with the added proviso that one allows the
metal to cool slightly to lose any redness it may have. (After
soldering an ear post I’d imagine that the post will have lost any
redness by the time it’s carried to the quench.) According to me,
using this advice the earpost will be nice and annealed. What do
others think?


Jewelers share their stories about working with findings.
By Tina Wojtkielo, 2004

Why are your silver ear posts so strong and mine are so
bendable? That’s a question Daniel Grandi of Racecar Jewelry
Co. Inc. in Cranston, Rhode Island, has heard from numerous
customers. The answer, he says, is simple. “After soldering
sterling silver ear posts onto models or finished pieces, you
should instantly quench them in cold water or hot pickle to
preserve tensile strength,” Grandi explains. “Most
craftspeople don’t do this, and their ear posts always turn out
soft.” Grandi adds that some craftspeople who aren’t familiar
with the quick quench method refuse to purchase ready-made ear
posts; they make their own by twisting wire with pliers. “All
the time they spend to work-harden wire and make their own ear
posts could be saved by a quick quench.” […]

After reading the article I wondered how to question the advice, as
there seems not to be a direct way from the article site, so I
decided to post here in Orchid and hope I’m not going to cause
offence. I just want to know what was intended, or maybe I could find
out I’ve been annealing the wrong way all these years. :wink:

Brian

B r i a n A d a m
e y e g l a s s e s j e w e l l e r y
Auckland NEW ZEALAND
www.adam.co.nz


#2

Brian,

I can see why you’re confused, because Daniel is recommending this
technique to work harden earring posts, and yet many of us were
taught in college to quench right away after annealing.

Years ago, my students were having lots of trouble with annealing.
It’s always a challenge to learn, it’s hard to see. So their stuff
was not getting annealed. At the time I worked in Jewelers Row, so
I stopped in at the bench jeweler’s next store, and said, “Homer,
what gives, my students’ work won’t anneal and they’re really
upset.”

He said, “well, what are they doing?”

Me: “They heat the metal, quench it.”

He laughed. He laughed!

He said, “That’s your problem. You’re work hardening the metal.”

I began teaching annealing that way, no quenching.

Unfortunately, many students who come to me have already taken
classes and sometimes get really, really, really mad that I say no
quenching. They are sure that I am insane.

So, I posted here, I wrote to Tim McCreight.

Tim said annealing is more complicated than most of us were taught
and that you may quench after annealing, but only when the metal
reaches 700 degrees.

Since I don’t know when the heck that is, I don’t quench.

Elaine
Elaine Luther
Metalsmith, Certified PMC Instructor
http://www.CreativeTextureTools.com
Hard to Find Tools for Metal Clay


#3

I wondered the very same thing.

marilyn smith


#4

Brian, this is interesting. I’ve not tried it, but surely will. I
was taught after soldering ear posts, to quench as usual (allowing
for it to cool down a bit from the red stage) and then hold the end
of the post in a pair of pliers and twist it 3 times while pulling on
it. This hardens it immediately. But I think I’ll solder some posts
on scraps and quench immediately and see how it compares.

Kay


#5

I agree that quenching as soon as the red color dissapears from the
earpost sounds contrary to standard annealing methods for regular
sterling. However, it works well and we have never had " soft “
earposts. We silver solder probably 25,000 pairs of earposts per
year + - a couple pairs. We have had a lot of customers call us and
ask if the posts were fusion soldered as they are so strong and they
want to know our " trick” .

When we ask what their proceedure was, they tell us that they let
the earrings cool until they can be held by hand, then they put them
in pickle… when they come out, they are dead soft…

I had the same experience as they did 20 years ago and have always
quenched the earposts while they are hot and never had the problem
since.

Daniel Grandi
Racecar Jewelry Co. Inc.


#6

Ok so let me get this straight. I sort of have this problem. I work
in heavy 8 gage square sterling silver and 8 x 2mm to make rings. I
have very little light at my soldering area when I am annealing. I
bring my metal to a dull red and then I pick it up and drop it in the
water. Then into the pickle pot. When I take it back to the bench it
does not seem to be much easier to with then when I started. So I
just let it sit and cool for awhile. How long and is there too
long???

Thanks
Rodney Carroll
RC Gems


#7
So I just let it sit and cool for awhile. How long and is there too
long??? 

Let it sit til you can pick it up. Too long, yes, since we’ve read
on this list about “air hardening.”

Elaine
Elaine Luther
Metalsmith, Certified PMC Instructor
http://www.CreativeTextureTools.com
Hard to Find Tools for Metal Clay


#8

Rodney,

How long are you heating the metal before you quench it? Are you
using a torch or oven to anneal your Sterling Silver? Finally, What
type of Sterling Silver are you using?

I bring these three points up because each can effect the outcome.

If you are using a torch to bring fresh Standard Sterling Silver up
to the red color you may want to hold the color a little longer,
moving the torch all over the metal to keep it evenly heated. On
heavy pieces, try holding the red color for about 10 to 15 seconds
and then quenching in clean water.

If you are using scrap Sterling Silver and rolling your own or using
one of the deox Sterling Silver products you will have to experiment
with length of time.

Good Luck
Greg DeMark
email: greg@demarkjewelry.com
Website: www.demarkjewelry.com
Link Exchanges Welcomed


#9

Hello Brian and Orchidland

I have to agree with Daniel Grandi with one caveat. When soldering
the post on in the first place to heat it as little as possible. What
I do is to set up the earrings for soldering complete with flux and
solder in place (I do prefer paste solder for this, though I can just
as easily use wire solder too) and I stand my posts on a corner of my
brick in a small hole so they are standing. When ready I light the
torch and grab on post in tweezers and heat the earring until the
solder is molten, then I quickly put the post into the molten solder
and immediately remove heat. Hold still a second or two so as to let
the solder harden and quench immediately. I have not had problems
with soft posts with this method. Happy Halloween :slight_smile:

Karen Bahr “the Rocklady” (@Rocklady)
K.I.S. Creations
May your gems always sparkle.


#10
... When soldering the post on in the first place to heat it as
little as possible ... heat the earring until the solder is molten,
then I quickly put the post into the molten solder and immediately
remove heat. 

I can understand, Karen, that this will surely most likely result in
unannealed posts. It’s the method I use mostly too.

Brian
Brian Adam
Auckland NEW ZEALAND
www.adam.co.nz


#11

Sterling silver is at its softest when it is annealed at 650C (1202F)
then immediately quenched, at this point it’s hardness is 56 Vickers
and its tensile strength is 300 Nmm -2. If it is air cooled it will
be only slightly harder at about 60 Vickers due to the difference in
crystal structure. Quenched sterling is closer to a uniform solid
solution and air cooled will have a less homogenous structure and
will as a consequence be slightly weaker. However if you look at the
data for work hardened sterling its hardness can be as high as
140-180 Vickers and its tensile strength is up to 550 N mm -2 so the
effort in cold working the ear post will pay off with a greatly
improved hardness and tensile strength (as long as you don’t over do
it and twist the darn thing off).

To quote from Handy and Harman’s :
The Handy Book of Precious Metals
http://www.handyharmancanada.com/hbpm/hbpm.htm

  The alloy [Sterling] is entirely liquid at 1640F (890C.) -and
  entirely solid at  1435F (780C.) However, the degree of copper
  solubility in the solid  alloy depends on the heat treatment
  used, and the overall physical  properties of the sterling can
  be materially affected, not only by heating  the silver to
  different temperatures, but also by employing different
  cooling rates." 

Also

  Specific annealing procedures for sterling alloys should be 
  available from the supplier, and these recommendations should
  be followed scrupulously, since even small differences in
  temperatures and/or cooling  rates could significantly affect
  the physical characteristics of the alloy.

  Some people confuse air cooling with the age hardening process
  where sterling silver can be greatly hardened by heat treating.
  to do this you first heat the sterling to 750C (1382F) and hold
  it at this temp for 30 minutes then rapidly quench  the item is
  then heated to 300C (572F) for 1 hour. this will result in a
  sterling piece that has a hardness of 110-120 Vickers and a
  tensile strength of 350 Nmm -2. The heat treatment can only be
  done on items that are not soldered as 750C will melt all
  silver solders if the item has been soldered prior to treatment
  and soldering after treatment will anneal the item and remove
  all the hardness gained. 

Jim Binnion

James Binnion Metal Arts
Phone (360) 756-6550
Toll Free (877) 408 7287
Fax (360) 756-2160


@James_Binnion
Member of the Better Business Bureau


#12

I would imagine the important factor is the RELATIVE temperatures of
the object and the quenching solution. Normally we would want them
to be close. That’s why many usually wait til the piece cools down
and others keep the acid hot. We usually do NOT throw red-hot
objects into cold (room temp) pickle. Thus, immediate quenching in
cold acid would be very different from immediate quenching in hot
acid. The suddeness or slowness of the cooling determines the grain
structure and consequently the hardness.

Janet in Jerusalem