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Selecting bezel wire size


#1

Over the weekend I made some rings using small garnet cabs (post to
follow soon with pic’s).

I added my own bezel step so the setting would be open back, by
soldering a wire on the inside diameter I found that after I had
started to set the stone that the bezel was a bit to big in height.

Now, that they are done, I am not disappointed with the result but I
know it could have been better

My question is: How do you decide what size bezel wire to use? What
do
you measure and is the a rough calculation to use?

Laurie
Adventures of an Aspiring Silversmith
http://lauriejanekern.ganoksin.com/blogs/


#2

Laurie

bezel for - Round stone:
diameter + metal thickness x 3.14

  • Oval:
    one half length of stone plus width + metal thickness x 3.14

  • Square:
    length of side x 4+ metal thickness x 3.14

  • Irregular:
    wrap stone with a strip of paper or string, and mark with perm.
    marker etc,.Add metal thickness to end for proper bezel blank
    length… hope this is what you wanted…rer


#3
My question is: How do you decide what size bezel wire to use?
What do you measure and is the a rough calculation to use? 

Just use your eye, for heaven’s sake. Not hard. Put the stone into
the bezel on it’s seat, and you can see easily how high up the cab
the metal will come when burnished over. The minimum height is
determined by the shape of the edge of the cab, as the bezel has to
come up past any vertical section to where it’s actually closing in
over at least a little taper, if the stone is to stay in. Other than
that, no calculations or formulas. Just look at it… Generally,
with the stone in place in the bezel, you’re looking not just at the
overall total height from the outside of the bezel, where you judge
the aesthetics, but you also see the exposed inside where you can see
how much the bevel or taper of the stone will allow the bezel to
close over, so you can see if it will be enough to hold. This varies
from stone to stone, as well as depending on the thickness and type
of bezel metal. At a guess, you usually will want at least a half
millimeter of height above the contact point, for metal that will be
burnished or otherwise closed over the stone. But some stones will
need more to be secure.

Peter


#4
My question is: How do you decide what size bezel wire to use?
What do you measure and is the a rough calculation to use? 

Your question implies that given a setting style (bezel in your
case) and a stone, there are many variations. I happen to think that
has absolutely no voice in the matter. The stone decides what
dimensions are. Jeweler simply reads the signs.

A rule of thumb is that stone must look larger and brighter after it
is set, than before. Since bezel covers some part of the stone, it
seems not possible. But it is. There are no simple solutions. Every
stone is different and every stone requires different approach.

The only guidance I can offer is to use as little metal as possible,
and what is possible would be different in each and every case. What
you absolutely must not do, is to use some kind of a numerical
recipe. That would be a mistake.

Leonid Surpin
www.studioarete.com


#5

I have had a few emails in response to my question but they deal
with figuring the length of the wire.

I am looking to figure out the height (or some may say width of the
wire) i.e.1mm, 2mm, ?

Laurie
Adventures of an Aspiring Silversmith
http://lauriejanekern.ganoksin.com/blogs/


#6

Hi Laurie,

after I had started to set the stone that the bezel was a bit to
big in height. 

If that happens again when you test fit the stone, could you pop the
stone out, up-end the bezel and sand the top surface down until
you’re happy with it, then set the stone?

My question is: How do you decide what size bezel wire to use?
What do you measure and is the a rough calculation to use? 

Personally, I just eyeball it. I hold the cabochon against a steel
ruler, with the bottom of the cab against a major measurement, and
then look at the slope and decide how much I want the silver to fold
onto the stone - not too little so that the stone is not secured,
but not so much that there’s too much metal to fold in, leading to
possible gaps and puckering, and too little of the stone visible -
and that tells me how many millimeters to use. I go just a little bit
taller than where the stone goes from vertical to a slope. I make my
bezels from sterling sheet so that I’m not restricted to standard
sized bezel wire. If I want a 2.75 mm high bezel, or an 8.5 mm
bezel, it’s not a problem.

Helen
UK
http://www.hillsgems.co.uk
http://helensgems.ganoksin.com/blogs/


#7
I am looking to figure out the height (or some may say width of
the wire) i.e.1mm, 2mm, ? 

If you are looking for mathematical recipe, it is not going to be
helpful. But to satisfy the curiosity here is how the problem could
be approached:

Let’s assume that cabochon has perfect half-round profile (few of the
them are), and perfect round shape. The task is to have enough metal
and no more to hold the stone securely.

Minimum amount of metal depends on the thickness of the bezel. The
thicker the bezel, the taller it should be. The reason has to do with
how metal deforms.

There are 2 types of deformation: elastic and plastic. To hold the
stone securely, the bezel must be turned (deformed) into zone of
plastic deformation, which depends on metal thickness, and different
metals have different values.

Let’s say you determined that it would take 0.1 mm to change metal
irreversibly. Since we are dealing with half-round profile, the
circle of contact will be found 0.1 mm above the edge. That is you
theoretical minimum.

However, cabochons are not half-round. Their curvature is a sum of
several arcs of varying radiuses. Usually, area next to girdle is an
arc of very the very large radius and attachment line must be found
above it. How high above it will depend on the stone itself.

If stone is oval, the situation is even more complex, because
curvature would vary and you would have to determine the highest
point. Other shapes would introduce even more complications.

You should see it by now that practical approach is to determine
what is required by simply eyeballing the stone. Let the stone tell
you what it needs. With practice the skill would be developed in due
time.

If you read to the end of my mini dissertation, you probable wonder
if technique take skills which can only be developed with time, why
then bezel setting is the first thing taught in many school. Well,
you
would be justified in your puzzlement. It is a misguided practice
which I do not understand, but it is very common.

Leonid Surpin
www.studioarete.com


#8

I am looking to figure out the height (or some may say width of the
wire) i.e.1mm, 2mm, ?

Like Peter says, eyeball it. But if you haven’t done it enough to
have gotten the feel for it you need to consider a few things.

Since you’re talking about cabs specifically…is this a flat bottom
cab or does it have a belly to the bottom? This is important because
a flat bottom will, obviously, be easier to seat and therefor require
somewhat less height to the bezel. A bellied stone(wait til you try
oriental cut star saph’s) would have a rounded base to seat against
the metal. Its very nature means that rocking is a potential problem
so you might need more height to the bezel, depending on how steep
the sides are. Steeper means more height needed, generally. Bellied
stones will usually be recessed into the mounting, before you even
add the bezel.

Also consider the gauge of your bezel wire. Common misconception is
that thinner is easier to set than thicker. Balderdash I say.
Something like …010" is very unforgiving and risky to the stone
besides. You have no mush factor. If you elect to hammer set, the
strike force goes right through to the stone. If you burnish, the
stretching force distorts the thin material pretty easily, you might
wind up with an impossible to remove buckle, and the shallower the
sides of the stone the worse it gets. Go thicker… .020", …030",
sometimes thicker, depends. Thicker will also hold the stone, long
term, better than thinner, especially on steep sided cabs. Thicker
gauge is also more agreeable to aggressive finishing…polish too
much on a thin bezel and you could just polish the edge away…no
cure for that but a new bezel. A crisp bezel is a joy to behold. A
ratty edged indistinct bezel might make you stash it in a drawer.

Look at the girdle too. It should have at least some bevel to it. A
sharp, unbeveled girdle requires the overall bezel size be larger,
look for a loose fit stone to bezel. Here again, thicker material
will help. What you don’t want is to put pressure on the girdle when
setting. Like I mentioned thin material can transmit the force right
through. Thicker material has a more stable attachment to the
underbezel. You can also cut a little at the base of the bezel for
clearance if need be. You could also cut a relief inside, a place for
the bezel to fold along.

What Leonid says is right too…use as little as possible. So if you
want a low clean look to the bezel and yet still hold well, a thicker
gauge allows you to do that, there’s just more inherent strength to
it.

So wire width is just part of the story.


#9

Laurie -

What I do is hold the stone between thumb & finger and hold at eye
level, evaluate the profile. I judge the steepness of the rise/curve
from base to the top of the cab. Is it a tall or low stone? Is it
steep or gently rounded? Is it even all around (that is: the slope,
not the outline)?

I try to hold the stone in with the minimum of metal. A low-domed,
gently rounded stone will require less height on the bezel wire than
a tall stone, or one with steep sides, even if the footprint is the
same for all three.

I would take my possible bezel wires and compare them to the stone,
with the stone in front and the base flush with the bottom of the
wire. Imagine the wire bent over the curve of the stone, how it will
look, how secure it will be, how easy or hard it might be, especially
in tight spots (near another stone, bail, etc.).

It’s better to have a wire that’s too tall, than one that’s too low.
You can always sand down a tall bezel. This is an advantage if you
have a stone with irregular height - I have carved the bezel height
to accomodate the undulations in slope, or make it easier to close.

There’s no magic number for what’s ‘enough’ metal. Once I know the
wire is high enough to capture the stone, I let my sense of
balance/artistry/graceful flow regulate where I go from there.

I hope this addresses the nature of your question.

best regards,
Kelley


#10
Square: length of side x 4+ metal thickness x 3.14 

That doesn’t make sense. I usually do length of side X 4, plus 2X
thickness of metal and it usually needs stretching up a tiny bit on
a bezel mandrel (which I prefer because it ends up nice and crisp
then) - BUT then multiplying it by Pi (3.14) is wrong and would give
a bezel roughly three times the length needed.

Helen
UK


#11

I would first like to say…we all think differently. Some of us on
Orchid are brilliant, I am not one of them, some of us manage and
some of us struggle to figure things out…so having said that; to
quote from Creative Stonesetting by John Cogswell : “The height of
the finished bezel should be approximately a third to a quarter of
the height of the stone, depending on the wall thickness. Make the
strip slightly wider than actually needed-the bezel can always be
filed shorter, but it can’t be filed taller. Thicker bezels can be
slightly shorter than thinner bezels, with greater mass making up
for lesser height, bur even they should never be less than one-fourth
the height of the stone.”

Hope this helps.
Mary Frances


#12
cabochons are not half-round. Their curvature is a sum of several
arcs of varying radiuses. Usually, area next to girdle is an arc of
very the very large radius and attachment line must be found above
it. How high above it will depend on the stone itself. 

This is way over-complicating something which is actually not that
difficult. It’s like going to university to do a maths degree
because you want to learn how to calculate the area of a circle. It’s
overkill.

why then bezel setting is the first thing taught in many school.
Well, you would be justified in your puzzlement. It is a misguided
practice which I do not understand, but it is very common. 

Your view puzzles me. I would have thought that the object of many
short-term jewellery courses is to enable the student to make a
piece of wearable jewellery. The skills involved in that will cover a
range of basic skills, from cutting, forming, soldering and
finishing. Many people like to set a stone in their jewellery so the
simplest stone setting is the place to start. What could be simpler
than bending a piece of metal into a circle, soldering it closed,
improving the shape and fit, sanding the top and bottom and soldering
it onto a backplate. Then trimming and filing the edges smooth, etc,
etc. The stone setting is also a relatively simple excercise,
especially with supervision of a teacher. Yes, there are a number of
factors to take into account, but they can be learned very quickly to
a standard that will enable you to make a serviceable setting.
Experience after the fact will then enable improvement of bezel
settings.

Even with longer jewellery courses, a method for setting stones
needs to be taught fairly early on, and prong, pave, bead, channel,
gypsy/ flush, etc, etc, are all far more complicated to achieve than
the simple bezel setting of, say a round cabochon. As you say, the
stone dictates the height of the bezel, and it can be very quickly
deduced by eyeballing the stone against a ruler or existing bezel
wire, or by using a vernier caliper or dividers, example. The best
bezel thickness for the stone is quickly learned, as is the most
appropriate method for achieving the setting of the stone.

Bezel settings/cups for faceted gems are another matter, which have
other considerations such as thickness of girdle, depth of pavilion,
evenness of girdle around the stone, degree of slope of pavilion,
etc, etc. However, having taught myself how to bezel-set all shapes
of both faceted and cabochon stones, I can say that even settings for
faceted gems are easy enough to learn if you’re determined and you
have the right tools - and good results can be achieved if you learn
from all your mistakes.

Helen
UK
http://www.hillsgems.co.uk
http://helensgems.ganoksin.com/blogs/


#13
Your view puzzles me. I would have thought that the object of many
short-term jewellery courses is to enable the student to make a
piece of wearable jewellery. 

The object of any course in jewellery making should to teach how to
make anything which can be called jewellery. Quality bezels are above
any beginner’s skill set.

Leonid Surpin
www.studioarete.com


#14
The object of any course in jewellery making should to teach how
to make anything which can be called jewellery. Quality bezels are
above any beginner's skill set. 

I think the key here is the term “quality”. I still wear the very
first ring I ever made, at the beginning silversmithing class I
took. Bezel set two-color stone. I love it, I constantly get “oooohs
and aaaaahs” from folks on it. Is it a “quality” bezel? Heck no! Is
it an adequate bezel? For sure! Did it inspire me to continue in
metalsmithing, to learn more, to improve? You betcha!!!

The bezels I make today are way, way better than this one - but what
I wear is the first one. I sell the ones I make now!

The key is in being clear with yourself and your students as to what
your aim is. When I teach beginners, my aim is to inspire them, to
instill a love for metal work, and confidence that yes - they really
and truly CAN do this. They know that they are not going to walk out
of a beginners workshop with “quality” professional work - they
don’t expect that, I don’t expect that. But they DO walk out with
work they are excited about, that encourages them to continue either
on their own or with additional classes with me or with someone else.

I have had adult students who have taken a wide number and variety
of art/craft workshops tell me my beginning workshop was the best
they ever did - because I made sure they did something unique that
pushed them and was successful, that they loved, and that they will
wear. That doesn’t mean it was “quality”.

I’ll be doing a copper workshop next week that will include some
students who took an earlier class with me this summer, and some who
are friends with those folks who heard such great things that they
want to take a class too. Because of this mix I’ve changed what
we’ll be doing to something that will work for both groups, and my
hope is that we will have enough interest to make it a monthly or
twice-a- month open sort of class where they can come and work. I
love teaching, and love seeing students of any age ignite with
passion for what they are doing.

On a related note, today I’ll be helping my 18 year old daughter
with her craft students at the recreation department summer camp. I
came up through an MFA program, and am trained in painting,
printmaking, paper making, and fiber art. The jewelry started as a
kid, then vanished to reappear when the above daughter wanted me to
teach HER when she was a kid. So yesterday we helped the kids (ages 4

  • 10 - now THATS a challenge!) make paper pulp. Today we’ll help them
    couch sheets of paper, which my daughter will then help them make
    into little “books”. Are their sheets going to be “quality” sheets of
    paper? Of course not!! Will they BE sheets of paper that each child
    made themself? Yes!!! How exciting is that for the kids - to actually
    make their own paper?

I think beginning classes in anything are based on imparting some
basic level of knowledge and competence, but a high level of
excitement that encourages the student to continue.

Kudos to everyone who teaches and passes on knowledge and passion,
in whatever field.

Beth Wicker
Three Cats and a Dog Design Studio
http://www.bethwicker.com


http://bethwicker.ganoksin.com/blogs/


#15
I think the key here is the term "quality". 

Yes, term quality does require an explanation. I subscribe to
philosophy that the best work must be done during training. Once
training is completed, realities of life make it very difficult to
bring each and every piece to the degree of refinement required,
unless rigid discipline is exercised. But in order to exercise the
discipline, one must know, how quality looks and feels, and that
knowledge can only be imbued during training by requiring virtually
flawless execution. To put simply: " the more you ask, the more you
get ".

Leonid Surpin
www.studioarete.com