Setting a cabachon into a 4 prong setting

Does anyone have instructions or advice for me as to how to set a
10x14mm oval cabachon into a 4 prong setting? More specifically, on
how to make the seats. I think I need a tool like a cup bur, but
something that grinds on the outside surface, not the inside of the
cup. I’ve searched the Internet and my reference books and have not
been able to find any info. However, I have seen rings like this, so
I know it can be done.

Lynn -

Get John Cogswell’s book on stonesetting. It’s detailed and
well-written with lots of illustrations. I think you will find what
you need in it.

Four prong setting for? In other words, what are you setting the cab
into? I have done prong settings using wire or you can make prong
type settings instead of a bezel. The method changes with the type
of jewelry being made (ring vs pendant as an example).

John

Lynn,

Based on the questions you have asked I will venture to guess that
you do not have any stone setting experience.

We all need to start somewhere and Orchid is the place to learn.

For a stone the size you mentioned 10 x 14mm in a cabochon I think
the easiest method for a beginner would be to use a half round needle
file.

Lay the stone on top of the prongs so you understand the
relationship of the stone to the metal. Now simply file a concave
shape on the inside of the prong that will match up to the profile of
the stone cutting the seat approximately 1/3 the thickness of the
prong.

Once you have the seat created there are various methods to clean up
any burrs that have formed along the edge of the prong. You can use a
file, a graver or rubber wheels.

Make sure you polish the prongs before you set the stone.

Good Luck
Greg DeMark

One of the main points to remember when cutting a seat for a cabachon
on a setting intended for a faceted stone is to insure the cutting
angle matches the curve of the cab on the prong,and since I presume
you have a standard oval cab, a round bur may be used first to thin
the prongs a bit so it can be rubbed over the cab…a seat is only
necessary if the setting isn’t large enough so that when you drop the
stone in place, the prongs don’t simply fold over the cab…If it (
the setting ) raises the cab higher than flush with the bottom of the
setting, using a 45 degree hart bur, or a cylindrical cutter can be
used around the base to make the stone settle down into the pre-made
setting.Once it is seated the prongs can be thinned a bit,as cutting
a traditional notch doesn’t work well on a smooth curve…on the other
hand, you can also use any bur you like to shape the prongs to -
starting at the base of the prongs, where the stone is seated -curve
over the stone and add your own design touch to the appearance of the
prongs…All the prongs need to do is bend/fold to match the angle on
the stones sloping side. Prongs that are not pre-notched may just be
too bulky looking so a slight tapering may be all that’s needed to
hold it securely…Tim McCreight’s* The Complete Metalsmith* has some
great on basic stone setting- if it’s not already in your
library you may want to add a copy or borrow it from your local
library…hope this helps…

rer

I have taken a ball bur and ground off the end of it,so that it is
flat on the bottom. Then you can cut your seat with that.

Hello All,

The bur that I was thinking about can be created by grinding down a
ball bur so that it has a flat surface. Thanks to Phil at Rio Grande
for telling me that a mizi wheel will work if you don’t have a
grinder available. Their tech support is always VERY helpful.

Lynn
www.lynnwhitejewelry.com

My own guess (and the way I’d do it if I wanted to set such a stone
that way) would be to make a sort of bezel but not to go around the
stone but rather for the stone to sit on top of, so I’d use much
thicker silver for such a large stone (perhaps 0.8-1.0mm thick).
This would form the seat so would have the same dimensions as the
dimensions of the stone. The seat would be filed/sanded flat to
support the cabochon’s back and the prongs would be soldered onto
the outsides of the setting. If the stone needs more support than
such a ring of metal, then perhaps you could solder a pierced plate
onto the top of the seat (so it’s a sort of inversed bezel cup)
before soldering on the prongs?

Looking forward to reading other people’s methods.

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

Get John Cogswell's book on stonesetting. It's detailed and
well-written with lots of illustrations. I think you will find
what you need in it. 

My new year resolution was to tone down my rhetoric if there is
something that I disagree with. Well, it is January 8 and out of the
window it goes.

I have read this book. I have sincere doubts that the author set a
single stone in his life, which he did not have to glue to the
setting in order to keep it in place. I cannot recommend this book.
Not only it is useless, it is dangerous!.

Leonid Surpin

Does anyone have instructions or advice for me as to how to set a
10x14mm oval cabachon into a 4 prong setting?

make a sort of bezel but not to go around the stone but rather for
the stone to sit on top of 

I completely misread the question! Doh!

Kelley’s suggestion to Lynn, of getting John Cogswell’s book reminds
me again that it’s a book I should probably get. Many, many
Orchidians have recommended this book at various times so I think
I’m going to invest in it as my jewellery is pretty much all about
the setting of stones.

Thanks for the reminder Kelley!

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

Since its an oval you won’t be able to cut all the seats in one
shot, you cut the prongs either in pairs or one at a time. If you use
a bur you will find it wants to dig into the prong or dance around,
making the cut off-center from the prong, hard to compensate for
without some experience. I prefer to cut prongs like this with a
cutoff disc. You have complete control of where and how it cuts.

If you’re using a finding wire basket setting the top rail is of
course round wire. This is not ideal for a cab. You’d like a solid
flat foundation for the cab to rest upon, if you cut the seat
somewhere up the prong you increase the likelihood of losing the
stone… Also the round wire is not all that aesthetically pleasing
under a cab. If you can, make the top rail out of square stock.

Now simply file a concave shape on the inside of the prong that
will match up to the profile of the stone cutting the seat
approximately 1/3 the thickness 

Several have covered what is actually a simple job (after the first
time…), but to elaborate a bit:

Setting a cab into a cab setting (four prongs on a flat base) is
just a matter of fitting the cab by cutting back the prongs till the
stone just drops in - no ratttling - and pushing the prongs over. A
separating disk works well for roughing, then a file to detail it.
There is no need or reason to cut the prongs concave, as they will
bend over the stone - that’s just wasted effort. Usually it’s better
to prefinish the prongs - clip them down to finished height, file
them to shape, taper the top edge, etc. Then just push them down…
Most stones that are routinely cabbed don’t respond well to rubber
wheels if they are touched… If the stone has a convex base, you’ll
need to dish out the bottom of the setting to match that - round
bur, usually, then rubber wheel…

Setting a cab into a standard four prong setting like a die-struck
melee setting is a little trickier, but not much. Your bearing cut
should look just like an “L” - a flat base with a straight edge
coming up, also to fit with no rattling, also better to prefinish
the prongs, usually. Separating disk, wheel bur, hart bur held
sideways, or cone square burs are some choices for roughing, and
again file or graver for finishing the bearing…

Based on the questions you have asked I will venture to guess that
you do not have any stone setting experience.

Yes, I do have some experience in stonesetting (see some bezel
settings in my “First Collection” on my website). I will admit I’m a
beginning stonesetter, however. I have taken a semester of
stonesetting, including bezel, prong, bead, and channel as part of a
technical degree in jewelry repair and fabrication. I have the book
Creative Stonesetting, as well as The Complete Metalsmith-
Professional and I am waiting patiently for Oppi’s book which has
been on backorder from Amazon since last October. This type of
setting was not addressed specifically.

To clarify things, this is a premade setting from Stuller,
1902:64898:S, 14KY. I want to set the stone so the bottom is just at
the top of the scrollwork on the setting. The stone is too big to fit
in the base of the setting and has nothing to rest upon. However, if
seats are cut in to the prongs, it should work. I have made a smaller
version of this ring at the same time to practice on. I need to reset
the stone in the smaller ring, which I’ll do when I get my ball bur
ground down.

When I have the ring completed I’ll put a photo of it on my blog.
Thanks everyone for your advice!

Lynn White
www.lynnwhitejewelry.com

My new year resolution was to tone down my rhetoric if there is
something that I disagree with. Well, it is January 8 and out of
the window it goes. 

What a wonderful goal Leonid! I support you fully in that.

Elaine
http://www.CreativeTextureTools.com

I cannot recommend this book. Not only it is useless, it is
dangerous!. 

Why do you say this Leonid? I bought myself the book (John
Cogswell’s book on stonesetting) for Christmas. It came a couple of
days ago so I have just begun to read it, but so far everything looks
very good with easy to understand explanations of the methods he
uses. His methods are not always my methods, but then I bought the
book in order to learn more ways of doing things. The illustrations
are good, and the many pictures of jewelry are outstanding. I would
like to know what there is that is “dangerous” in the art of jewelry
setting.

Jan McClellan

Helen,

Kelley's suggestion to Lynn, of getting John Cogswell's book
reminds me again that it's a book I should probably get. 

Echo! Echo! Cogswell’s book is awesome. You won’t regret the
investment.

Jamie

I cannot recommend this book. Not only it is useless, it is
dangerous!.

Why do you say this Leonid? I bought myself the book (John
Cogswell's book on stonesetting) 

Well, Leonid’s setting is pretty rough, too. I haven’t read the
book, but I found a few excerpts online and it looked OK - page 117
was pretty bizarre, frankly. Probably as good as you’re going to get
for a book about setting.

The real point is that you’re only going to learn so much from a
book at all - not that you shouldn’t try, if you want to. Like all
of goldsmithing, setting is actually craftsmanship - it’s in your
hands. It’s really quite simple: You pinch the stone between an
upper bearing and a lower bearing. A bezel is an upper bearing, and
the base is a lower bearing. A bead is the upper, and the seat is
the lower. Channels and prongs have a “bearing cut”, usually with a
hart bur, that is both bearings in a notch. Then you just push the
metal over and crimp it down, pinching it between the two bearing
surfaces. Once you understand that, then setting becomes clear. It’s
the skill that’s the hard part.

I know “how” to set everything - mentally, that is. And I do a fair
amount of work. But there are jobs I send to a diamond setter,
because I just don’t have the elevated skill to do a proper job. I
mentally know how, I am simply incapable of that level of setting. I
rejected setting a.03ct. diamond next to a previous stone because I
just didn’t know how to match the previous work, which it needed to.
Beautiful, professional setting work, that. Just one simple little
stone…

And stone setting is directly tied to setting design and
engineering, whether you design it or it comes to you - plus
calibrated stones and settings rarely exist outside the classroom.
Those exotic settings in the book are more the product of minds who
understand setting design than how the stones ultimately get set -
that’s the easy part, in the end. And setting design is a lifelong
avocation… It’s like polishing - do the preliminaries properly and
the final buff will take 20 seconds. Design a good setting and the
stone will just pop in…

That’s not to unload on the book or on books in general. Everybody
needs to understand that it’s just a glimpse into a vast field,
though. It’s not going to make you a setter, though it will no doubt
provide much insight into what is needed. I know a good dozen pro
diamond setters - all they do is set stones - and they are all
different, they all use different methods and tools, and they all do
good work, some better than others. It’s not how you get there, it’s
what you end up with in the end…

For the Stuller setting - make bearing cuts like an “L” - flat
bottom, straight up sides, just to fit the stone tight. Insert
stone, push prongs (adjust height), eat cake.

Hi John,

That's not to unload on the book or on books in general. It's not
going to make you a setter, though it will no doubt provide much
insight into what is needed. 

Exactly. I am planning to buy the book to get further insight into
the world of stone-setting and to get a glimpse into someone else’s
perspective on it. I have read other books on stone-setting also,
including a book on diamond setting by a renowned author. Having
read other people’s methods, there were things in that particular
book that just didn’t seem right (as more modern methods had
superseded them) but I find that I learn just as much from things I
don’t agree with as I do from things I do agree with. Just like an
experiment that goes wrong - it tells you an awful lot once you know
why it went wrong. The book in question has had many more positive
recommendations than it has negatives. I always read books with an
open mind - never taking anything as THE only way to do it.

So I’m confident John Cogswell’s book will have lots I can learn
from and that many of his setting techniques will be things I’d like
to try, either as they are or adapted to my needs.

Helen
UK

I have read other books on stone-setting also, including a book on
diamond setting by a renowned author. Having read other people's
methods, there were things in that particular book that just didn't
seem right 

I’m glad people took my comments well, as they were intended. It’s
just the usual caveat - reading books does not a goldsmith make. Bead
setting is the perfect example - “Put the stone into a seat cut just
about ~that depth~. Get a very sharp graver and make a little bead
2,3 or 4 times around the stone, at which point the stone is set.
Finish in any of various ways”. Simple? Yes, but try it sometime.
It’s all in the hands, ultimately. But again, that’s not to say
everyone shouldn’t read as much as possible, either. We have a
library, too…And yes Helen, there is much bad advise out there,
too. I’ve seen the most bizarre things relating to setting,
especially. Usually they involve agonizing over things that just
aren’t that complicated…

just the usual caveat - reading books does not a goldsmith make 

You are the 1st to say what I have always said, read it, try it &
see what happens.

Mike