# Keeping half-round wire aligned for soldering

``````much is fairly well understood by all. The problem comes in with
the cold worked part. If you have not reduced the section of the
metal you are working on by 50 % or more then you are not getting
much if any recrystallization period end of story.
``````

I’m afraid I’m guilty of not really understanding what you’re saying
Jim. I get confused with what the metal crystals are doing. At what
stage are they large and what stage are they smaller again? Which is
the hardest state, small crystals or big crystals?

``````You have to put a lot of cold work into the metal to get enough
stress into the crystal lattice for the recrystallization to
occur.
``````

What is the cold working doing to the crystal lattice. My brain says
that it’s breaking down the lattice into smaller pieces, but if that
was the case, you’d think that more movement would be possible, and
therefore a softer metal - so I’ve clearly got my thinking
completely upside down, back to front, etc. So please could you
clarify in simple terms, what is happening to the lattice when the
metal is cold worked, and then what happens when it is annealed?
Thanks.

Sorry to ask such simple questions, but I seem to have a bit of a
mental block on it.

Helen
UK

Hi Helen,

This is how I explain it to my students. Jim, if you’re reading this,
please jump in if I get it wrong, I came up with this explanation

Step one: this is a vast oversimplification of what’s really going
on. It’s more to give you a mental model than anything passing for
serious metallurgical knowledge.

Step two: Imagine a shoebox, and a bucket of golfballs. Pour enough
golf balls into the box to cover the bottom in one layer. Notice
that they line up into a grid sort of like eggs in an egg-crate. If
you were to pour another layer in, they’d settle into the divots
between the balls in the previous layer. So you’d end up with the
same grid, but offset half a ball to one side, and most-of-a-ball
higher. Pour in a bunch of layers, and you’ll get a three dimensional
grid or lattice of golfballs.

The golfballs are actually metal atoms, and you can think of the
shoebox as a sort of fuzzy stand in for a metal crystal, or metal
domain, or a grain.

When jewelry metals start to solidify from liquid, they start out
solidifying around some sort of impurity or something else that
serves to get the grid going, and then the rest of the atoms sort of
join the crowd. Once they see how the grid’s forming, they know where
to put themselves, so they line up with the matrix that’s growing
from that original seed point. This happens all through the
solidifying object pretty much simultaneously, so there are lots of
different starting points, and lots of different grid matrices that
don’t line up with each other once everything solidifies. This is
actually good. If you had a perfectly even grid, you’d have something
as hard (and brittle) as a diamond. No way to forge diamonds. It’s
the discontinuities between the crystals (shoeboxes) that allow the
metal to bend and flow.

Imagine a semi-trailer full of those boxes of golf balls, loaded by
a bunch of guys at 4:45 on Wednesday afternoon before thanksgiving.
There are going to be a lot of boxes just tossed into the trailer,
with a lot of holes and gaps between them. Now imagine Godzilla
(that’s you) picks up the trailer and tries to tie it in a knot. The
boxes are full of perfectly packed golfballs, so they’re not going
to compress much, but as the trailer flexes, there’s plenty of room
for the boxes themselves to slide around, which lets the trailer
bend. Through the magic of tortured analogies, the boxes can change
size to fit into smaller spaces, so long as they change shape along
one of the axes of their internal matrix.

So, Godzilla trying to tie the trailer in knots is roughly
equivalent to you, taking out your aggressions on the poor hapless
metal with a hammer. Otherwise known as cold working. Every time you
bend or hammer the metal, the metal domains (or grains) slide around
like those boxes in the trailer. The incredibly minute gaps between
them let them slide around, and shuffle themselves into a new order.
Every time you do that, the holes get smaller, and smaller, and
smaller, until eventually there aren’t any left, and the metal snaps.
An interesting thing to keep in mind is that the holes are only going
to disappear in areas where the metal’s deforming. If Godzilla grabs
the ends of the trailer and twists, the middle will eventually shred,
but the two ends may stay just the same as they were to start with.

Annealing is roughly equivalent to Godzilla getting frustrated, and
breathing fire on the whole thing. (You never knew you were the
metallurgical equivalent of Godzilla, did you?) Godzilla breathes
fire, the trailer goes up in a ball of flame, and the boxes burn.
Which lets the balls (metal atoms) reorganize themselves into a
loose grid without quite melting. As the fire department shows up,
they hose down the trailer, (you quench the metal) and the
temperature crashes back down, the same sort of recrystalization
happens, and once again, the spirit of tortured analogies appears, to
recreate the boxes, all jumbled up in a brand new trailer, just
waiting for Godzilla to have his next fit.

In a less goofy version, annealing relaxes the grain boundaries. The
crystals don’t quite fully dissolve. (if they did, the metal would
melt), but it lets the outlier atoms start to drift around, and look
for greener pastures. However, metal atoms being susceptible to peer
pressure, the longer you hold the metal at heat, the longer the
surviving grains have to say “Oh! Oh! Come hang out with the cool
atoms!” which makes the surviving grains get bigger and bigger. As
you quench the metal, the wandering atoms are forced to pick a team,
quickly. So many of them glom onto the surviving grains, while others
form new grains based on impurities (or whim), so you end up with a
new discontinuous structure, with a fresh batch of microscopic holes
to let the grains shuffle themselves around. This is why it’s better
to push the metal as hard as you can, and anneal as quickly and
infrequently as possible: less time for the ‘cool kid’ grains to
extend their domains.

The reason big grains are bad is that the grains would really
rather shuffle around based on their external boundaries. They
really don’t like to deform themselves. They can, but it takes a
lot more energy to do that, and if the metal’s already been pretty
seriously worked, that may just be enough to shred it. So the bigger
the grains, the harder it is for them to find spaces into which they
can shuffle, and the more likely they are to just snap. (In getting a
grain to deform, you’re asking the atoms to shear along one of the
planes of the internal matrix. If one of the planes lines up with how
you want it to move, great. If not… ) It is actually possible to
see how the internal grain orientation effects a sheet’s formability,
I don’t remember all the details, but I know Charles Lewton-Brain has
done some work on this, relating to foldforming. I remember pictures
(somewhere) where you can actually see the metal moving differently
in different directions.

Who knew that Godzilla and high-school cliques had anything to do
with the inner life of metals?

On a serious note, I mostly teach older adults. I find they remember
better if (A) you give them examples they can relate to, and (B) if
they’re laughing. Thus Godzilla and the high-school prom.

So, Jim, I’m almost afraid to ask how far off I am… Remember: the
goal is a mental model that predicts what the metal’s going to do,
not textbook precision.

Regards,
Brian.

``````What is the cold working doing to the crystal lattice. My brain
says that it's breaking down the lattice into smaller pieces, but
if that was the case, you'd think that more movement would be
possible, and therefore a softer metal - so I've clearly got my
thinking completely upside down, back to front, etc. So please
could you clarify in simple terms, what is happening to the lattice
when the metal is cold worked, and then what happens when it is
annealed?
``````

Jim is quite capable to answer for himself, so all I am going to do
is to offer practical demonstration of what he is talking about.

Take a copper sheet of 24 gage ( 0.5 mm ). See if you could do very
deep repousse pattern on it. If cycles of annealing and working the
copper are correct, you should be able to achieve the hight of the
pattern exceeding pattern projection at least by factor of 3 and
more. Silversmiths who do a lot of raising know it very well. If

Heating causes re-crystalization. If metal is under-worked, the
result of re-crystalization is larger crystals. The larger the
crystals, the more brittleness.

Leonid Surpin

As a new person working with metals I did not understand your
posting and I would really like to understand because it sounded
critically important. For example what do you mean by putting the
cold work in? Did you mean pushing the metal in a cool state as far
as possible before annealing again or something else?

I was also unsure of what you meant “reducing” the size of the
section of the metal by 50%. Did you mean thinning the section of
metal?

Thanks.

Who knew I had to work the metal enough to anneal. Thanks for

Esta Jo Schifter, finally selling stuff in Philly. Website soon.

Hi Brian,

Thanks so much for your explanation! It was so funny, but so
informative too. I get it now. For some reason, I was thinking of it
as one big crystal lattice, and so it all seemed back to front to
me, but thinking about it as grains, each with their own crystal
lattice, and how those grains interact with each other makes perfect
sense. It also explains how not working the metal enough before
annealing would lead to crystals that are too large and therefore
brittle metal.

Thanks again.
Helen
UK

``````I'm afraid I'm guilty of not really understanding what you're
saying Jim. I get confused with what the metal crystals are doing.
At what stage are they large and what stage are they smaller again?
Which is the hardest state, small crystals or big crystals?
``````

Well that all depends on how the metal is treated during processing.
Lets look at sheet metal. Typically the crystals are going to be
largest just after the ingot is cast. This is also typically when it
is at its softest. As it is rolled down to sheet those crystals get
flattened and stretched in the direction of rolling so they become
long and flat. As long as there is not so much strain on the lattice
that it fractures the grains just get flatter and longer. There is
some small amount fracturing of the grains but mostly they are just
distorted by the stress. As the strain increases the lattice becomes
more difficult to deform so it gets harder. With wire it is similar
but the grains get smaller in crossection and longer as it is drawn
or rolled down.

``````What is the cold working doing to the crystal lattice. My brain
says that it's breaking down the lattice into smaller pieces, but
if that was the case, you'd think that more movement would be
possible, and therefore a softer metal - so I've clearly got my
thinking completely upside down, back to front, etc. So please
could you clarify in simple terms, what is happening to the lattice
when the metal is cold worked, and then what happens when it is
annealed?
``````

Inside each crystal are layers of atoms in a 3D array. When you
stress the metal crystal by hammering, rolling drawing etc entire
layers of atoms will atually slip across the adjacent layers in
reaction to the stress. These are called slip planes. This is a
significant difference between metals and other crystaline elements,
other types of crystals will fracture rather than slip. During this
slip movement irrgularities in the array form or are accentuated.
Some of these defects called dislocations are critical to the
recrystalazation process. These defects are actually storing some of
the energy that has been put into the metal cold during working.
These defects limit the ability of the planes in the crystal array to
slip. So as the lattice deforms the grains just get more distorted by
the stress and the lattice becomes harder because the slip planes are
constrained by the growing number of defects. Eventually if you
continue to work the metal the number of defects will be so great
that there is no more ability to slip and the stored energy can no
longer be contained in the lattice and it fractures. This is what has
happened when you work a piece of metal to the point that it breaks.

If you dont push the metal to the breaking point you have this
lattice that has lots of strain (stored energy) in it. During the
annealing process as you increase the temperature of the metal the
atoms are able to move about more freely and some of the strain is
released from the lattice and the grains begin a process called
recovery where the atoms in the crystals move about to reduce the
strain and try to heal the disslocations in the array. If you were to
stop here you would have a strain relieved piece of metal but not not
yet annealed (recrystalized). As further heat energy is added to the
metal the dislocations with their already high stored energy act as
nuclei for the growth of new crystals. This is how you end up with
smaller crystals, not from breaking the larger ones down but rather
by creating areas favorable to the growth of new crystals. If you
actually put enough energy into the metal to break the crystals you
break the metal. If you continue to heat the metal beyond the
recrystallization stage you end up in the crystal growth stage where
the stored energy in the lattice is gone and the crystals try to
reduce the boundary area in the lattice by absorbing their neighbors
and if conditions were right would eventually try to become a single
crystal. Although this single crystal state will not happen due to
impurities in the metal and other factors you can grow some huge
crystals if you hold the metal at elevated temperatures for long
periods of time.

So why will the metal not recrystallize if you don’t work it enough?
The answer is in the stored energy in the dislocations. If there is
not enough stored energy from cold work to act as a nucleating site
for a new crystal formation the distorted crystal will just relax
and then proceed to grow without forming new small crystals.

So to recap,

Cold work distorts the crystals in the matrix making the matrix
stiffer (harder).

Some of the energy from cold work is stored by defects
(dislocations) in the crystals atomic array.

During heating after cold work if there is enough energy stored in
the crystals you go through three stages

1. Relaxation (strain relief) where much of the stress is released
from the matrix

2. Recrystallization (annealing) where new crystals grow at the
dislocation sites.

3. Crystal growth where the grains get larger.

If there is not enough energy in the crystal matrix you only get two
stages, relaxation and crystal growth

This is a quick explanation of a subject that can fill volumes so it
is incomplete but hopefully accurate as far as it goes.

Regards,

Jim
James Binnion
James Binnion Metal Arts

``````If you had a perfectly even grid, you'd have something as hard (and
brittle) as a diamond. No way to forge diamonds. It's the
discontinuities between the crystals (shoeboxes) that allow the
metal to bend and flow.
``````

No, the difference between a molecule like diamond and metal
molecules is in the type of atomic bonding. You can get off into
quantum theory in a hurry when talking about atomic bonds but
basically a chemical bond like many non metal molecules have is a
sharing of a certain number of electrons between atoms in the
one is Valence Bonding and the other is Molecular Orbital Theory you
electrons are likened to a sea or cloud of electrons that travel
around the mass of the metal molecules. It is my understanding that
this loose association of the electrons in the atoms outer shell is
what allows the slip of one layer of atoms in a crystal across
another without breaking the bound between them. Whereas if you push
a chemical bond hard enough to dislocate a layer of atoms it
fractures the bond and the crystal.

``````So, Godzilla trying to tie the trailer in knots is roughly
equivalent to you, taking out your aggressions on the poor hapless
metal with a hammer. Otherwise known as cold working. Every time
you bend or hammer the metal, the metal domains (or grains) slide
around like those boxes in the trailer. The incredibly minute gaps
between them let them slide around, and shuffle themselves into a
new order. Every time you do that, the holes get smaller, and
smaller, and smaller, until eventually there aren't any left, and
the metal snaps. An interesting thing to keep in mind is that the
holes are only going to disappear in areas where the metal's
deforming. If Godzilla grabs the ends of the trailer and twists, the
middle will eventually shred, but the two ends may stay just the
``````

In your analogy it is that the golf balls in the boxes that are
shifting across each other not that there is space between the boxes
allowing the boxes to shift

``````Annealing is roughly equivalent to Godzilla getting frustrated,
and breathing fire on the whole thing. (You never knew you were the
metallurgical equivalent of Godzilla, did you?) Godzilla breathes
fire, the trailer goes up in a ball of flame, and the boxes burn.
Which lets the balls (metal atoms) reorganize themselves into a
loose grid without quite melting. As the fire department shows up,
they hose down the trailer, (you quench the metal) and the
temperature crashes back down, the same sort of recrystalization
happens, and once again, the spirit of tortured analogies appears,
to recreate the boxes, all jumbled up in a brand new trailer, just
waiting for Godzilla to have his next fit.
``````

no this is not correct see my note to Helen

``````The reason big grains are bad is that the grains would *really*
rather shuffle around based on their external boundaries. They
*really* don't like to deform themselves. They can, but it takes a
lot more energy to do that, and if the metal's already been pretty
seriously worked, that may just be enough to shred it. So the
bigger the grains, the harder it is for them to find spaces into
which they can shuffle, and the more likely they are to just snap.
(In getting a grain to deform, you're asking the atoms to shear
along one of the planes of the internal matrix. If one of the
planes lines up with how you want it to move, great. If not... ) It
is actually possible to see how the internal grain orientation
effects a sheet's formability, I don't remember all the details, but
I know Charles Lewton-Brain has done some work on this, relating to
foldforming. I remember pictures (somewhere) where you can actually
see the metal moving differently in different directions.
``````

There are several problems with big grains, first the grain
boundaries are where many of the impurities in the metal end up so
there is lots of junk there that may not be as ductile or malleable
as the core grains. Second if a small grain boundary fails the crack
will likely have great difficulty propagating as the crack energy
will be dissipated by many surrounding grains each with a different
orientation that makes it hard for the crack to continue. When a
large grain boundary cracks the energy will be absorbed by a smaller
number of adjacent grain boundaries and may propagate to one or more
of the surrounding grains adding its energy to the crack and then it
an travel much further leading to a large failure in the matrix.

``````So, Jim, I'm almost afraid to ask how far off I am... Remember:
the goal is a mental model that predicts what the metal's going to
do, not textbook precision.
``````

Yes, and for the most part your analogy works as well as an analogy
can maybe clean up a couple of areas and keep using it.

Regards,

Jim

James Binnion
James Binnion Metal Arts

Hi Jim,

Thanks for the input. I was faking it based on what I knew, but I’m
a long way from a metallurgist.

The handout version that I actually do give out talks about the
electron cloud, and compares it to rubberbands.

The version you saw was me re-writing it on the fly Wednesday
evening. The handout version doesn’t have Godzilla, for example.
Although I think the next version will. I like the giggle factor of
comparing annealing to Godzilla getting frustrated. Once I fix the
science, the image will still work.

I didn’t know about the stored stress energy, and that being a
source of crystal genesis points during recrystalization, and I
always thought the movement was largely of the domains sliding around
externally, rather than internal slip-shear across the matrix. That
alone was well worth knowing. Thanks.

More later, once I have time to digest turkey and the rest of your
posts.

Regards,
Brian.

PS–> I’ll send you both the current Godzilla-less version, and
whatever the revised version ends up being.

Gee this has been a mammoth thread!

Fascinating

I have never really had this problem, possibly because I anneal as
seldom as possible and often make heavy silver rings using oxy
propane to solder usually using enamelling solder.

I have had students who want to anneal every few minuets, which
wasts time and degrades the metal structure.

Even when I do make thinner rings or twists it is not a problem. I
usually solder on a piece of old kiln shelf or large carborundum
chips. You can easily stick your work deep into the carborumdum and
just heat the area you want.

Suggestion 1. overlap ring size on ring stick just too small.

``````During this slip movement irrgularities in the array form or are
accentuated. Some of these defects called dislocations are critical
to the recrystalazation process.
``````

Probably we’d all like to thank Jim for his explanation - I knew a
bunch of it, but I could never lay it out so clearly.

With that said, I’ll point out that almost everybody here doesn’t
need to know all of that in such detail, though it’s good for you,
too. When your metal at the bench is hard, you usually need to make
it soft… I rolled a bezel last week, annealed it, and wrapped it
around the stone and it came up short. So I put it through the mill
another time - far from the 50% reduction Jim talks about… Then I
needed to anneal again, of course.

It’s the reality of work at the bench… When you are running a
foundry and putting out mill products, doing heavy repousse and
forging and what Jim does, mostly - mokume with lots of rolling and
the like, then what he discusses becomes very important and you can
calculate things for optimum results. Don’t take it so far as to
think that you can’t, or shouldn’t anneal your metal at the bench
because it’s part of life - big grains, small grains, it needs to be
worked anyway, most of the time…

Hi James,

Thank you very much for your detailed explanation of the working and
annealing processes. It really has helped me to understand it, so
many thanks indeed. I liked both yours and Brian’s explanations and
I think I’ve got it now.

Helen
UK

Suggestions:

1. Wrap half round wire around the mandrel, sizing it just below the
size you want.

2. Saw through the two sections vertically. I use a saw with the
blade reversed so I am cutting on the push against the bench pin. This
takes a little practice. Very useful for making jump rings. The two
ends should fit perfectly, though may need a touch with a file on the
ends to remove any irregularities.

3. With two pairs of parallel pliers overlap the ends slightly to
the left then to the right, now bring the two ends together without
opening the gap, allowing the tension to keep the gap closed.

4. Check that there a perfect join, if there is an irregularity, saw
through the touching ends cutting through each side of the cut,
thereby removing any irregularities.

5. Re-tension as before, overlapping to left and right. Then
reposition the ends. It may be necessary to slightly twist each end
to get them to a-line perfectly on the inside curve. Using a pair of
1/2 round pliers.

6. Recheck joint prior to soldering.

7. Flux and gently heat the joint area to dry flux. Apply hard
solder, enough to completely fill the line. Gently heat the joint
again until flux melts and reposition the solder if necessary. Using a
titanium pusher. Take care to heat both sides of the joint equally,
as solder will flow to the hottest area.

Bring up to temperature as quickly as possible and remove flame when
solder has flowed.

If the solder has not filled the line, place another piece of solder
on the line and reheat, repositioning the solder if necessary.

1. If the joint is not prefect, either re-saw and refit as before.
Or if the ends have parted file off any solder on ends and refit.

2. After the ‘perfect’ ring has been in the pickle file off any
excess solder before malleting on the flatblock and mandrill till the
required size is achieved.

I hope this has been of some use. I try not to blind you with
science!

jewellerydavidcruickshank.com.au

``````If there is not enough energy in the crystal matrix you only get
two stages, relaxation and crystal growth
``````

Jim, as usual your explanations are superb! Where I run into this is
when hammering into shape a heavy bracelet that is not uniform in
cross section, some sections being weaker than others. I will often
anneal several times during that process, even though I might not
have moved things sufficiently to store enough of the energy you
described. I get paranoid about the breakage potential of the weaker
sections. But is your relaxation stage all I need for preventing
breakage? Does that mean going all the way to annealing temperature
is pointless if all I need is a little breakage insurance during the
final stages? What temp causes the relaxation and are there any
specific visual cues to indicate it? Thanks!

Allan

``````But is your relaxation stage all I need for preventing breakage?
``````

In general practice, yes

``````Does that mean going all the way to annealing temperature is
pointless if all I need is a little breakage insurance during the
final stages? What temp causes the relaxation and are there any
specific visual cues to indicate it?
``````

Boy that is the \$60,000 question and the answer is in practice no
there is no way to know on a given piece what the exact stress
relief temperature or annealing temperature is. Sure you can run
destructive tests that will tell you if you reached the proper
temperature. But the lab tests are useless in a practical real time
studio environment. Even under ideal lab conditions it is not clear
you can tell exactly what temperature stress reliving starts and what
temperature annealing starts and what temperature crystal growth
starts. They kind of blend into each other.

So we must rely on the data that has been collected in the past and
make some assumptions as to how hot is hot enough. So the best
advice is to take the temperature data you can find and your own
studio experience and make a best guess. Just remember that you can
damage the metal by heating too often and too hot so don’t just
anneal on a whim, put some work into the metal first.

Jim

James Binnion
James Binnion Metal Arts

Hi David,

``````Saw through the two sections vertically. I use a saw with the blade
reversed so I am cutting on the push against the bench pin. This
takes a little practice. Very useful for making jump rings. The
two ends should fit perfectly, though may need a touch with a file
on the ends to remove any irregularities.
``````

put the blade in upside down? (to what we usually do with the teeth
down?) or did you mean reversed so the teeth are on the inside of
the frame? I guess that would take some practice. LOL

I make quite a few rings and bangles from 20ga. silver with widths
of 3/8" to 3/4", flat stock, or square, but still have trouble.

I’ve always had difficulties getting the two sections exactly
fitting, which means, that I end up filing more and more off either
side. Eventually it works, but seems it really is a slow process, I’m
always seem to take off too much even if I only make two passes,
gently, one area or the other is off.

Finally I was told to get it the best I could, solder it, and saw
through it after quenching it and solder again.

Is there another way of ensuring that this double soldering isn’t
necessary? What is it that I’m missing? I’m tapping the ends with a
mallet around the ring mandrel or bangle form, so that the opposing
sides touch in the correct arc.

I have more issues with the flat wide stock than with rings, which I
don’t have a problem with seemingly because of the diameter or small
area of the wire I’m using. I use a magnifying head set and a good
file. I use a flat surface to file on, or bench pin (depending), and
check after each pass.

Thank you for any suggestions.
Dinah

Sorry. Dinah

The teeth of the saw blade point forward and you cut on the push
against the bench pin. Takes a bit of practice, but can be very useful
once mastered.

Of course you can saw through the soldered joint, sometimes I have
to do so, but seldom. When you saw try to get the saw to follow an
imaginary line straight through the centre of the ring. Try a courser
blade for thicker material #1 or 2 (not #02> >) And dont saw across
the top of the ring vertically downwards. Hold the ring near
vertically but saw with the saw at about 45 deg. and at right angles
to the ring. Start gently then using long strokes vary the angle of
the saw slightly upwards and downwards so the teeth are in contact
with less metal. Let the saw do the work, take your time and DONT
apply any real downward pressure. When you have to file of any
irregularities, and indeed for all filing, have a good light source,
(I dont like strip lighting) arranged so the light reflects off the
area you are filing, this enables you to clearly see what you are
doing.

Also get the feeling of holding things in your holding hand against
your bench pin, so you always work at the same angle and the same
applies to your filing hand. Get comfortable, everything should be
set up for comfort, pin below nose height, straight back, low seat,
feet flat on floor, and arms at a comfortable angle. It all helps.
Use two pairs of 1/2 round pliers to get the natural twist corrected
from the coil of rings or bangles.

Then maybe use the mallet so the inside of the ring is flat.

``````The teeth of the saw blade point forward and you cut on the push
against the bench pin. Takes a bit of practice, but can be very
useful once mastered.
``````

Sorry David,

Personal preference. I cut on the down stroke and use the bench pin
for support.

Mark