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Damnable Prongs!


#1

I can not seem to notch prongs properly. I read about doing it
but never see pictures of the notch shape. I use a triangular
file and have been trying to set ovals into four prong, wire
basket type settings. When I get done, the prongs do not seat on
the stone correctly. Are there any secrets or tricks I can use?
Are there easier settings for stones?

Thanks,

Bob B

I’m still plugging away but admiring more and more the skills of
a bench jeweler!


#2

I use a half round file and watch what the prong is doing to the
stone as it is going down. On brittle stones, a lot of care and
attention needs to setting the stone. Sometimes I will "crease"
the prong ever so slightly just to influence where the prong
starts to bend. Then insert the stone and set.


#3

try cutting your prongs with a 45degree hart burr available at
your local dealer of jewelry tools & equip. use a 05-08 ball
burr for those stones with less sharp girdles or very deep
bellies (rouded pavilion facets) it takes practice so cut a
little and look a lot. be sure you look at the stone and see the
angle and thickness of the girdle in all four places the prongs
will touch and cut the notch to match ,also be sure and cut the
prongs low enough to provide good leverage at the top when you
push them, and finally practice practice practice. good luck!


#4

Bob,

One of your problems is that oval stones tend to have a bulging
pavilion (the lower part of the stone, below the girdle).
Usually stone setting is done with a flex shaft and the seats are
cut using any one of s number of different bur types. To
overcome the bulge, a ball bur is used to round out the area of
the prong below the point where it is bent over. In your case,
since I assume that you are doing everything with files, you
should use an oval or half round rile and round out the lower
half of the area you filed with the three sided file. This will
take some trial and error to get your stones to sit properly.

Another possible area of trouble, is the proper orientation of
the seat you file. It is important to match the angle at which
you file your seat to the angle at which is meets the curvature
of the stone. Again. keep checking your work as you go along to
be sure your filing correctly.

Hope this makes sense and helps.

Sharon Ziemek

P.S. If you plan on doing a lot of stone setting, invest in a
flex shaft rotary tool and some burs. If you have lots of money
(haha) take a course or two with GIA when they are in your area.


#5

I can not seem to notch prongs properly. I read about doing it
but never see pictures of the notch shape.

There are excellent pictures and explanations in the Hoover &
Strong and little Stuller findings catalogs that are short and
easy to follow. I notch my prongs individually instead of trying
to do them all at once with a setting burr the same size as the
stone. I clean up the notch with a knife edge brown wheel which
removes the burrs and makes the seat slightly rounded which will
reduce the stress in the prong. It takes lots of practice, so
take your time and don’t get discouraged! Wendy Newman


#6

This prong thing has come up at a good time for me. I’m going to
set an oval garnet in my crude little basket setting with four
prongs. (My first gold soldering, jeez it IS different!) I’m a
little confused as to when to use a Hart Bur or a regular stone
setting bur. I had planned to use a regular setting bur and do
each prong at a time then set the stone. I thought Hart burs were
mostly for channel setting? I had to turn down a job for a
neighbor to cast a good ring and set several diamonds in
it…this stone setting stuff is a little out of myleague right
now except for bezel stuff. PS. … I just got a 40 watt
ultrasonic used from Gesswein’s website and I LOVE IT! No more
scrubbing with a toothbrush in a cup of full strength amonia.
What a timesaver…Dave


#7

Dave,

Congratulations on the ultrasonic! Don’t be disheartened with
stone setting. It takes time and practice to get consistent
results (well, almost consistent results). I had learned from a
book called “Diamond Setting, The Professional Approach” by
Robert R. Wooding (pub: Dry Ridge Co.). It got me through until
I could afford a workshop on stone setting. If which bur to use
seems confusing, it is. Different people use different burs in
each type of setting. It’s not so much a question of right vs.
wrong, but one of which works best for you and gives you the best
results.

Good luck!

Sharon Ziemek


#8

Dave, i alsways use a hart or ball burr for prongs it gives me
more controll over the shape of the cut. the only time i use a
setting burr is for bezel work. use the edge of the hart burr at
an angle and cut from the bottom of the seat up to shape the cut.
tapering away from the prong at the top of the seat to leave it
as heavy as possible you are only notching the prong 1/3 to 1/2
of its thickness. judge where to start your cut and measure from
the gallery of the basket up as opposed from the top of the prong
down. prongs are almost never the same length and this will help
to insure the stone is level. cut a little and look a lot,
remember the seat you cut should match the shape of the stone
where the prong will touch. stone setting is something that takes
a lot of practice so don’t get discouraged. good luck:) frank


#9

Hi, Dave. 99% of the time, I use a 90degree bur for setting in
prongs or flat setting. The only time I use a hart or 45 degree
bur is when I am channel setting round stones only. I use ball
burs for channel setting baguettes. I take a 90 degree bur that
is smaller than the stone and cut each prong individually. If I
am working with a large stone, sometimes I will use a pair of
dividers and put a small scribe mark on the outside of each
prong - from the top - to get the seat level (provided all the
prongs are the same height). On most colored stones, I tilt the
bur inward to allow for clearance of the pavilion, and sometimes
if the girdle is very thick, I walk the bur up and down the prong
very slightly and shape the prong to the girdle. You’re on the
right track, and I’m sure with a little practice you will be a
pro at it. Good Luck, Ken


#10

Anothe way i sometimes use on basket and tube type heads is to
cut the complete prong at a very shallow angle. A sanding disc
works very well. I start at the top ,cut fairly thin, and taper
it to the base of the prong,hardly cut at all at the very bottom.
I then spread the prongs out wide enough so the belly of the
stone touches the lower support of the head. Then you can see
where the girdle of the stone is going to touch. >From those
points i “pre break” the prongs with flat nosed pliars. then set
the stone in place, push the sides of the prongs in toward the
belly of the stone and push them down onto the stone. They are
usually a little long,makes for good leverage, so i just cut them
off with flush cutters and dress with a file. I end up with nice
thick prongs that fit the stone well. Works good on all types of
stone,fat,thin,perfect. also it is very fast once you gey the
hang of it. Helps a lot when you have to set up 30-40 pairs of
erngs or pends.