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[Help] how to set a princess cut stone?


#1

Ugh! Can anyone help? I am an aspring jeweler and I am doing new things
everyday. Today I am making a engagement ring for my cousin and need some advice
on how to set a princess cut stone in a setting I got from Hoover and Strong. I
could just wing it but I thought that I would see if anyone could help first. I
assembled and sized the ring part it is just the stone part that petrifies me. Can
You help me?


#2

Tiffany, you will probably get many different tips on how to set a princess cut
diamond. Two methods I use; if the stone is under 1/2 carat, I first use a drill to
remove the metal where the points will be. I follow the drill with a bud shape bur
and finally use a 90 degree bearing bur to make the notches for the girdle. The
whole prong tip is polished and then bent over the tips of the diamond. The second
method I use is for stones larger than 1/2 carat; I repeat the process above and
then I use an 8/0 saw blade and make a slit in the middle of the V part of each of
the prongs; down to the girdle line. The tips are bent down until the slit closes
up. This slitting process is repeated until the tips of the prongs are completely
folded over the diamond. A burnisher is then used to burnish down the metal at the
cuts to hide them. The tops of the prongs are dressed down with a knife edge file
and lightly polished. Ken Sanders


#3

Tiffany Soo, Of course we can help you. To be brief In the case of V-prongs first
lightly file the tops of the prongs just enough to make them even. Then use a
small ball bur about a size .06 or ,07 to bore a pocket about half way into the
spine of each prong about 1/2 to 3/4 mm from the tips. Make sure they are all the
same depth. This is necessary to protect the points. You do not want the points to
actually press against the metal. However, be careful not to bore all the way
through. Afterwards use a small (about 1mm) 90 degree bearing cutting bur, or a
hart bur to cut straight into the pockets of the prong tips. Keep the bur shaft
held upright at each prong tip to cut the two lips on each prong equal in depth
and level. This is done to fit the girdle of the diamond into the prong tips as
well as the point. The diamond will be seated loose. To tighten the diamond,
gradually squeeze the opposite prongs closer with miniature chain nose pliers.
Keep the plier jaws below the level of the bearings at first to avoid prematurely
bending the tips over. Just squeeze a little at a time. Might even try squeezing
adjacent prongs slightly towards each other. To complete the securing procedure
bend the tips over slightly. To do this brace one plier jaw low on the setting and
place the other jaw high on the opposite prong tip. Just bend the tips a little.
Do this to each prong tip. Don’t try to tighten the diamond all at once. If the
diamond is still a little loose slightly squeeze the lips of each V-prong onto the
girdle of the diamond. To do this be careful. Spread the plier jaws equally onto
the narrow prong lips with the pliers held at a low angle from outside the
setting. From this position the pliers should avoid direct pressure on the
diamond. The rest is finishing. Take your time R. Wooding


#4

Thank you all so much for your quick and vry good advice. It
eases my nerves so much to know that there are people out there
who can and want to help a newbee like me. Thanks again, I
owe you all a debt of gratitude. -Tiffany


#5

Soo, I can give you an idea.First lay the stone onto the head so
that it is oriented the way that looks best.Most princess cuts
are not square so you have to orient each one differently.Next
make sure the tips or corners of the stone are aligned with the
prongs on the head looking over the table or top of the stone.Iam
assuming you are setting the stone in a standard white gold
solitare type head.If the prongs are not aligned meaning the
tips of the diamond are not lined up with the v’s on the prong
take a needle nose jewelers pliers and gently spread the prongs
where they need to be to line the tip or corner of the diamond
with the v of the prong.When I use the term spread it means
miniscule movement of the prong.If you have to move the prong
alot the head is too small.the next thing I do is to imagine
where the diamond is going to be once you set the stone.You want
to have it set down enough to have enough of the prong hold the
stone. If you cut your seats to high you won’t have enough prong
to hold your stone.I look at the head from the side with the
diamond laying in the head and imagine a sphere on the end of the
prong and imagine the diamond dropped down into the head so that
sphere is bent over the corner of the stone the sphere would sit
just above the girdle.This gives me an idea of where to cut my
seat.You can mark this point with a scribe or fine felt tip
marker.I pick out a small ball burr a little less than half the
width of the prong if it is too wide it will eat away the sides
of your prong. Hold the ball burr up to your prong to
measure.This is your prong looking down from the top <+o=DDD
The < sign represents your prong the horizontal cross bar on the
plus sign is the point where you burr a small cup for the tip of
the stone.The o is the tip of your ball burr enlarged the= is the
shaft of your ball burr and the DDD represents the handpiece of
your fordom or whatever.(Whew)You burr a small cup in all four
corners of the head on each prong. Where you want the four
corners of your stone to rest they should be all four level so
the stone sits level.The cups should not be more tham 50% of the
prong.After I get those burred out I take a heart burr and cut a
seat that is not more than 50% of the prong in the middle of the
cup I just burred for the tips of the stone. This seat is cut
horizontally.Next I take the heart burr I just used to cut the
seat and run a line vertically at the base of the seat I just
cut on each prong it does not have to be very long This is to
accomodate the keel at each corner of the pavillion of the
stone.Then I completely buff and clean the head and setting.Then
after being cleaned in the ultrasonic and steamed.I set the
stone.I use (and some will cringe)pointed parrallel jewelers
pliers to gently and I do mean gently bring the prongs
together.I close the pliers corner to corner from opposite
corners .Until the stone will not fall out Then I bend the prongs
over until the are resting on the crown above the girdle of the
stone.Then take needle nose jewelers pliers and squeeze the v’s
slightly.Next I finish of the tips using a cut off wheel and a
blue silicon knife edge wheel.Then rebuff and clean.I would
HIGHLY recommend going to your local mall jewelry store and
looking at princess cut solitares with their loupe.They will be
more than happy to help out, trust me.That way you can get an
idea of how they are set.Warning they may not be set right,trust
me.It is very hard to describe this in detail using e-mail.Oh and
yes you CAN break the tips of Princess cuts or any other diamond.
Happy Trails J Morley


#6

Very good description J Morley: Having worked at the bench for
over 30 years, your coaching is very correct. I had the
opportunity to set a 3.05ct princess cut diamond while the
customer watched through the window. I installed a platinum
setting in her existing mounting and set her stone while she
waited. Our shop is enclosed in glass so that the customer can
watch us while we work. This particular customer was watching
less than 2 feet from my bench top. I use a twist drill to
provide clearance for the points, a 90 degree bur for the girdle
and finish with a 45 degree to provide clearance for the
pavilion facet from the point. Working the prongs with the needle
nose pliers is the part that makes me very cautious. I have been
fortunate that I have not broken any points off of the diamonds.
I work slowly and most of my settings are in Platinum.

Regards:
Roger W. Kitchens
Personal Web: www.homestead.com/r_kitchens
Email: myjeweler@yahoo.com


#7

Rodger, Try using a ball bur (appropriate size) to bore holes to
protect the points of a princess cut diamond inplace of a twist
drill. Also applies to pear, marquise, heart, etc. R. Wooding


#8

Rodger, I work in the same confines and I have a window out into
the hall way of the mall that I am in.I enjoy letting people
watch me and watching other people.I set up an n guage train and
it has little houses and cars with jewelry in the window.It
realy gets peoples attention.Someone once told me human beings
are attracted by three things movement,fire and sex.I’ve got the
train and my torch.In my previous store I was not proected from
the public.Two and a half years of having people hang over my
bench while I worked on grandmas heirloom thingamabob was the
ultimate in patience.It also completely cured me of any anxiety
I had while having people watch me work.Now I don’t even notice
people watching me work.Iam getting more platinum head requests
and I enjoy setting stones in them.Its like butta. Regards J
Morley Coyote Ridge Studio


#9
    Very good description J Morley: Having worked at the bench
for over 30 years, your coaching is very correct. 

I like your description, concise, at least for someone with a
working knowledge of stone setting. I tend to go in and clean
up corners a bit with a 1.0 mm inverted cone bur, and I use a
small ball bur to clear for the points, but then open that up a
bit with a bud bur. I tend not to do much more than bring the
prongs in to meet the stone, then slit the “v” a bit, not down
to the stone, then slowly pinch the “v” in a way as to decrease
the anle inside the “v”. I’ll clear it back out with a
polished flat graver, after sanding outside to get some nice
looking angles.

    I work slowly and most of my settings are in Platinum. 

I insist my customers who buy any stone larger that 3/4 carat us
a platinum head because, a.) it’s safer to set with, dead soft
so no sudden movements. b.) the prongs don’t wear out for 40
years or so. c.) no dreaded “prong shear” due to nickel content.