Hardening sterling silver

On Thu, 11 May 2006 22:19:51 -0700, in rec.crafts.jewelry "Dr. Memory"
wrote:



I've used this to harden my wedding band which is made from .9999
I made the band (constructed not cast, and fused together).
I made it like 5 sizes too small, sub-zero quenched it, then stretched
it up on a ring stretcher.
It's VERY hard, just like a 14k band.
I guess YMMV.

Doc


Well, to put it bluntly,

"DUH".

First, you fabricated it, no doubt forging it and rolling it, and the like. So
now it's got a nice strong and dense structure of nicely small crystals, even if
you annealed in when you welded it shut (which you might not have entirely done,
witn some types of welding.

Then, you stretched it five darn sizes. Sh*t. most karat gold wedding bands
won't take kindly to stretching that far, at least not without needing some
major work on the finish, but pure gold will, though I'll bet you had to work on
that finish a bit too, after stretching. To put that into perspective,
stretching it five sizes lengthed the circumference of the band by about 12.5
millimeters. That's a lot of elongation. No wonder it's now nicely hard.

My point is, your sub zero quench had nothing to do with it. Your fabricating
the band, and then stretching the heck out of it, was quite sufficient todo
that nicely. Now, if you actually were to test the hardness of the metalon a
standard metalurgical hardness tester (which most of us don't have), you'll
likely find it's still a bit less than 14K. But pure gold, due to it's density
and great ductility and malleability, may well seem that hard. Work hardened
like that, it will share some of platinum's resistance to wear and tear and
abrashion, with scratches displacing metal instead of removing it. And normal
wear will also repeatedly burnish and lightly hammer the metal, further work
hardening it over time.

Pure gold is indeed very soft when fully annealed. But fully work hardened,
it's quite durable (just think about gold coins (the ones that are actually pure
gold, not a gold copper alloy) Ever seen one really bent up? They'll get
dinged up, but not actually all that must faster than other coins in other
metals. What distinguishes pure gold most from those other metals, or gold
alloys, is that when work hardened fully, it reaches a state of maximum
hardness, at which point it can still be worked, almost indefinately, without
really getting much harder. The alloys, when worked past their state of maximum
hardness, will crack or otherwise fail. But in use, you don't normally
experience this difference as the gold being somehow softer. Only that for
whatever reason, you can continue to work it to your hearts content witout it
failing. The fact that you can draw it down almost forever or beat it into
leaf, all without it needing annealing, in no way implies that during this
process it stays soft. it doesn't. It just reaches it's maximum work hardened
state, and then continues to be workable at that level of hardness.

Again, let me repeat myself. Your sub zero quench does nothing but make the
metal very cold, perhaps very fast. This does not change it's structure in any
way, though while still cold it's likely harder, but this is not a permanent
change, just it's condition when super cooled. If you are annealing themetal
and then very rapidly cooling it with such a quench, you'll more completely
preserve whatever structure exists at the high annealing temp, limiting whatever
changes in structure take place if the metal cools slowly. For this to have any
meaning, there has to be some potential difference in structure between low and
high temperatures. Gold has no such dual structure. Look at a phase diagram
for the metal (though you may have some trouble finding a phase diagram for pure
goldl, since it's pretty boring. Nothing to diagram. Just a melting point,
then a vaporization point. To get a 2d graph you might actually find, you have
to relate these two to pressure... which I'm not sure would still be considered
a standard phase diagram. (?) But even with that chart, you'll see no different
structural phases beyond solid, liquid, and gas. It's the same face centered
cubic structure throughout the solid phase. Nothing else, so far as i know, at
least not within the normal pressure ranges we're likely to encounter.

Out of curiosity, do you understand the mechanism by which pure gold is
malleable/ductile, and by which it work hardenes? (I'll leave that for another
post. 'nuff now.)

Peter

On or around Fri, 12 May 2006 05:47:46 GMT, a poster allegedly named
"Peter W.. Rowe," drooled

On Thu, 11 May 2006 22:19:51 -0700, in rec.crafts.jewelry "Dr. Memory"
wrote:



I've used this to harden my wedding band which is made from .9999
I made the band (constructed not cast, and fused together).
I made it like 5 sizes too small, sub-zero quenched it, then stretched
it up on a ring stretcher.
It's VERY hard, just like a 14k band.
I guess YMMV.

Doc


Well, to put it bluntly,

"DUH".

First, you fabricated it, no doubt forging it and rolling it, and the like. So
now it's got a nice strong and dense structure of nicely small crystals,even if
you annealed in when you welded it shut (which you might not have entirely done,
witn some types of welding.

Yeah. Fused it. Can't be .9999 if I used solder.

Then, you stretched it five darn sizes. Sh*t. most karat gold wedding bands
won't take kindly to stretching that far, at least not without needing some
major work on the finish, but pure gold will, though I'll bet you had towork on
that finish a bit too, after stretching. To put that into perspective,
stretching it five sizes lengthed the circumference of the band by about12.5
millimeters. That's a lot of elongation. No wonder it's now nicely hard.

My point is, your sub zero quench had nothing to do with it. Your fabricating
the band, and then stretching the heck out of it, was quite sufficient to do
that nicely. Now, if you actually were to test the hardness of the metal on a
standard metalurgical hardness tester (which most of us don't have), you'll
likely find it's still a bit less than 14K. But pure gold, due to it's density
and great ductility and malleability, may well seem that hard. Work hardened
like that, it will share some of platinum's resistance to wear and tear and
abrashion, with scratches displacing metal instead of removing it. And normal
wear will also repeatedly burnish and lightly hammer the metal, further work
hardening it over time.

Pure gold is indeed very soft when fully annealed. But fully work hardened,
it's quite durable (just think about gold coins (the ones that are actually pure
gold, not a gold copper alloy) Ever seen one really bent up? They'll get
dinged up, but not actually all that must faster than other coins in other
metals. What distinguishes pure gold most from those other metals, or gold
alloys, is that when work hardened fully, it reaches a state of maximum
hardness, at which point it can still be worked, almost indefinately, without
really getting much harder. The alloys, when worked past their state ofmaximum
hardness, will crack or otherwise fail. But in use, you don't normally
experience this difference as the gold being somehow softer. Only that for
whatever reason, you can continue to work it to your hearts content witout it
failing. The fact that you can draw it down almost forever or beat it into
leaf, all without it needing annealing, in no way implies that during this
process it stays soft. it doesn't. It just reaches it's maximum work hardened
state, and then continues to be workable at that level of hardness.

Again, let me repeat myself. Your sub zero quench does nothing but makethe
metal very cold, perhaps very fast. This does not change it's structurein any
way, though while still cold it's likely harder, but this is not a permanent
change, just it's condition when super cooled. If you are annealing the metal
and then very rapidly cooling it with such a quench, you'll more completely
preserve whatever structure exists at the high annealing temp, limiting whatever
changes in structure take place if the metal cools slowly. For this to have any
meaning, there has to be some potential difference in structure between low and
high temperatures. Gold has no such dual structure. Look at a phase diagram
for the metal (though you may have some trouble finding a phase diagram for pure
goldl, since it's pretty boring. Nothing to diagram. Just a melting point,
then a vaporization point. To get a 2d graph you might actually find, you have
to relate these two to pressure... which I'm not sure would still be considered
a standard phase diagram. (?) But even with that chart, you'll see no different
structural phases beyond solid, liquid, and gas. It's the same face centered
cubic structure throughout the solid phase. Nothing else, so far as i know, at
least not within the normal pressure ranges we're likely to encounter.

Out of curiosity, do you understand the mechanism by which pure gold is
malleable/ductile, and by which it work hardenes? (I'll leave that for another
post. 'nuff now.)

Peter

Peter, I'm sure you're a really smart guy. You certainly seem to know
stuff I don't know, but putting all that education aside (if you will)
just try it: Make two 24k rings (like I did) sub-z quench one, &c. and
just work harden the other.
You decide.
And no, I don't understand all that tech stuff.
I've been making jewelry for 30+ years and my customers are all very
happy. I have more work than I have time to do.
I don't believe I even *need* to understand all that stuff although it
is quite interesting, it doesn't put grits & hog jowls on the table.

A person could drive himself nutz reading all there is to read about
the technical side of metal working (just browse some Stuller metal
books!). I see a lot of would-be jewelers get hung up & frustrated on
all the tech stuff out there, and really they'd all probably be
happier & more productive if they'd just make jewelry and create art
and not worry so much about all these confusing and IMHO unnesessary
details.
(although as repair is my mainstay I sure wish y'all'd learn to solder
with plumb solders and stop with all that dang ultra easy stuff! Hey,
it'll make you sick!)

Doc

Dr. Memory wrote:


I've used this to harden my wedding band which is made from .9999
I made the band (constructed not cast, and fused together).
I made it like 5 sizes too small, sub-zero quenched it, then stretched
it up on a ring stretcher.
It's VERY hard, just like a 14k band.
I guess YMMV.

Doc



I have also used 24K to make my wife's and my wedding bands. Also fused
together. Also several sizes smaller then needed. Then forged them on a
mandrel to the right size with a hammer, instead of stretching. They arehard
enough for normal wear.

Your ring has become harder from the stretching, not from the quenching. If it
would have become as hard as 14K from the quenching you would not have been able
to stretch it 5 sizes without breaking or annealing.

--
Abrasha
http://www.abrasha.com

Dr. Memory wrote:



Peter, I'm sure you're a really smart guy.

Yeah, he is.

You certainly seem to know
stuff I don't know, but putting all that education aside (if you will)

Funny, you patronize Peter, and at the same time you claim to be working with
liquid nitrogen, which assumes a certain level of education. I would think that
you would be at least educated regarding this rather dangerous material (when
used improperly).

just try it: Make two 24k rings (like I did) sub-z quench one, &c. and
just work harden the other.
You decide.

Stubborn feller, aren't you. Peter is right, you're not.

So how are you going to test the difference in hardness without a metal hardness
tester? Do you keep one in your shop next to the liquid nitrogen?

BTW, I'm curious to know why you have liquid nitrogen in a jewelry shop in the
first place. This is not a liquid that you can just go out and get, and special
safety precautions need to be taken, since in the wrong hands it can be quite a
dangerous substance. And you need special containers to store the stuff in.
Liquid nitrogen is not a meterial typically found in a goldsmith's workshop.



And no, I don't understand all that tech stuff.
I've been making jewelry for 30+ years and my customers are all very
happy.

What's your point. My customers are happy too, and that doesn't make me a
metallurgist.

I have more work than I have time to do.

Unfortunately I don't

I don't believe I even *need* to understand all that stuff although it
is quite interesting, it doesn't put grits & hog jowls on the table.

I agree with you on that one. Being pragmatic about the whole thing willget
you far enough. A teacher of mine once told me, "In life, understanding will
get you the booby prize"


A person could drive himself nutz reading all there is to read about
the technical side of metal working (just browse some Stuller metal
books!). I see a lot of would-be jewelers get hung up & frustrated on
all the tech stuff out there, and really they'd all probably be
happier & more productive if they'd just make jewelry and create art
and not worry so much about all these confusing and IMHO unnesessary
details.

Some rudimentary knowledge is helpful and necessary.

(although as repair is my mainstay I sure wish y'all'd learn to solder
with plumb solders and stop with all that dang ultra easy stuff! Hey,
it'll make you sick!)

AMEN! This reminds me of a "simple" job I once had to do for a boss manyyears
ago, on a customer's ring. It was one of those awful cocktail rings, with many
small four prong settings soldered in a cluster around a center stone. All
single prong setting soldered together without a substructure, just held
together with solder. Very ugly, but if soldered properly quite strong.

Anyway, I had to add about half a dozen of these small setting to the
concoction. I knew it was going to be tricky, so I decided to use medium
flowing plumb solder, a safe bet for a properly constructed ring. The moment I
took my torch to the ring, the entire thing fell apart in a heap of metalon my
soldering block. I don't remember if I got fired that day or if it was afew
weeks later.

--
Abrasha
http://www.abrasha.com

Dr. Memory wrote:
On or around Fri, 12 May 2006 05:47:46 GMT, a poster allegedly named
"Peter W.. Rowe," drooled


On Thu, 11 May 2006 22:19:51 -0700, in rec.crafts.jewelry "Dr. Memory"
wrote:



I've used this to harden my wedding band which is made from .9999
I made the band (constructed not cast, and fused together).
I made it like 5 sizes too small, sub-zero quenched it, then stretched
it up on a ring stretcher.
It's VERY hard, just like a 14k band.
I guess YMMV.

Doc


Well, to put it bluntly,

"DUH".

First, you fabricated it, no doubt forging it and rolling it, and the like. So
now it's got a nice strong and dense structure of nicely small crystals, even if
you annealed in when you welded it shut (which you might not have entirely done,
witn some types of welding.


Yeah. Fused it. Can't be .9999 if I used solder.

Then, you stretched it five darn sizes. Sh*t. most karat gold weddingbands
won't take kindly to stretching that far, at least not without needing some
major work on the finish, but pure gold will, though I'll bet you had to work on
that finish a bit too, after stretching. To put that into perspective,
stretching it five sizes lengthed the circumference of the band by about 12.5
millimeters. That's a lot of elongation. No wonder it's now nicely hard.

My point is, your sub zero quench had nothing to do with it. Your fabricating
the band, and then stretching the heck out of it, was quite sufficient to do
that nicely. Now, if you actually were to test the hardness of the metal on a
standard metalurgical hardness tester (which most of us don't have), you'll
likely find it's still a bit less than 14K. But pure gold, due to it'sdensity
and great ductility and malleability, may well seem that hard. Work hardened
like that, it will share some of platinum's resistance to wear and tearand
abrashion, with scratches displacing metal instead of removing it. Andnormal
wear will also repeatedly burnish and lightly hammer the metal, furtherwork
hardening it over time.

Pure gold is indeed very soft when fully annealed. But fully work hardened,
it's quite durable (just think about gold coins (the ones that are actually pure
gold, not a gold copper alloy) Ever seen one really bent up? They'll get
dinged up, but not actually all that must faster than other coins in other
metals. What distinguishes pure gold most from those other metals, or gold
alloys, is that when work hardened fully, it reaches a state of maximum
hardness, at which point it can still be worked, almost indefinately, without
really getting much harder. The alloys, when worked past their state of maximum
hardness, will crack or otherwise fail. But in use, you don't normally
experience this difference as the gold being somehow softer. Only thatfor
whatever reason, you can continue to work it to your hearts content witout it
failing. The fact that you can draw it down almost forever or beat it into
leaf, all without it needing annealing, in no way implies that during this
process it stays soft. it doesn't. It just reaches it's maximum work hardened
state, and then continues to be workable at that level of hardness.

Again, let me repeat myself. Your sub zero quench does nothing but make the
metal very cold, perhaps very fast. This does not change it's structure in any
way, though while still cold it's likely harder, but this is not a permanent
change, just it's condition when super cooled. If you are annealing the metal
and then very rapidly cooling it with such a quench, you'll more completely
preserve whatever structure exists at the high annealing temp, limitingwhatever
changes in structure take place if the metal cools slowly. For this tohave any
meaning, there has to be some potential difference in structure betweenlow and
high temperatures. Gold has no such dual structure. Look at a phase diagram
for the metal (though you may have some trouble finding a phase diagramfor pure
goldl, since it's pretty boring. Nothing to diagram. Just a melting point,
then a vaporization point. To get a 2d graph you might actually find, you have
to relate these two to pressure... which I'm not sure would still be considered
a standard phase diagram. (?) But even with that chart, you'll see no different
structural phases beyond solid, liquid, and gas. It's the same face centered
cubic structure throughout the solid phase. Nothing else, so far as i know, at
least not within the normal pressure ranges we're likely to encounter.

Out of curiosity, do you understand the mechanism by which pure gold is
malleable/ductile, and by which it work hardenes? (I'll leave that foranother
post. 'nuff now.)

Peter


Peter, I'm sure you're a really smart guy. You certainly seem to know
stuff I don't know, but putting all that education aside (if you will)
just try it: Make two 24k rings (like I did) sub-z quench one, &c. and
just work harden the other.
You decide.
And no, I don't understand all that tech stuff.
I've been making jewelry for 30+ years and my customers are all very
happy. I have more work than I have time to do.
I don't believe I even *need* to understand all that stuff although it
is quite interesting, it doesn't put grits & hog jowls on the table.

A person could drive himself nutz reading all there is to read about
the technical side of metal working (just browse some Stuller metal
books!). I see a lot of would-be jewelers get hung up & frustrated on
all the tech stuff out there, and really they'd all probably be
happier & more productive if they'd just make jewelry and create art
and not worry so much about all these confusing and IMHO unnesessary
details.
(although as repair is my mainstay I sure wish y'all'd learn to solder
with plumb solders and stop with all that dang ultra easy stuff! Hey,
it'll make you sick!)

Doc


Master Doc,
Are you actually saying in your last paragraph that one should use plumb
solders on jewellery? ie solders based on lead?
Im quite ignorant to all this tech stuff too and would like to learn
all the supposed advantages from whom it appears to be a master?
Any help with lead slodering much appreciated.
Fred Tater
PS doest it go well with gold?
A beginner in dorset UK.

On Sat, 13 May 2006 03:11:21 GMT, Abrasha wrote:

BTW, I'm curious to know why you have liquid nitrogen in a jewelry shop in the
first place. This is not a liquid that you can just go out and get, andspecial
safety precautions need to be taken, since in the wrong hands it can be quite a
dangerous substance. And you need special containers to store the stuffin.
Liquid nitrogen is not a meterial typically found in a goldsmith's workshop.

How else do you make your ice cream?
--
Marilee J. Layman
http://mjlayman.livejournal.com/

On Sat, 13 May 2006 03:11:00 GMT, Abrasha wrote:

Dr. Memory wrote:


I've used this to harden my wedding band which is made from .9999
I made the band (constructed not cast, and fused together).
I made it like 5 sizes too small, sub-zero quenched it, then stretched
it up on a ring stretcher.
It's VERY hard, just like a 14k band.
I guess YMMV.

Doc



I have also used 24K to make my wife's and my wedding bands. Also fused
together. Also several sizes smaller then needed. Then forged them on a
mandrel to the right size with a hammer, instead of stretching. They are hard
enough for normal wear.

My wedding band is .999, made while I watched by a Korean jeweler 43
years ago. (Yes, I'm still married to the same woman :-) It tends to
flatten over time, so I remove it every couple of years and restore
the shape on a ring mandrel.

Your ring has become harder from the stretching, not from the quenching.If it
would have become as hard as 14K from the quenching you would not have been able
to stretch it 5 sizes without breaking or annealing.

--
Al Balmer
Sun City, AZ