As a jewellery nut and reader of jewellery making techniques, I
always scrutinise any jewellery that crosses my path. Having read a
lot about prong setting, with instructions to cut/file notches for a
stone’s girdle to sit in (but no more than a third of the prong’s
thickness), I have noticed that the vast majority of prong set
stones are not notched at all. The prongs on virtually all the
jewellery I’ve handled, have the whole prong width retained, and
each prong is just bent inwards to “secure” the stone. This looks
very insecure as far as I can tell.
Does anybody know why some jewellers make notches and others don’t?
To notchor not to notch? That is the question ;-). I want to take
the plunge and attempt prong setting again, but I’m interested in
the different techniques.
Does anybody know why some jewellers make notches and others
don't?
The correct technique is to notch. Technique of bending prongs is
the result of sub-contracting. To allow for notching, prong should be
relatively thick and long.
After setting the excess is clipped off. However, if job done by
outside contractors, the clippings stay with setter. When gold was
$300 it was acceptable, but when gold started to climb, the practice
became very costly. So the prongs became very thin and short.
The only way to set them is to bend around girdles.
Helen- It is imperative that you cut a good seat for a stone to sit
in. I always tell our setting students that it’s a properly cut seat
that really makes a stone secure. All the prongs in the world will
not make that stone secure if you don’t have a good seat.
I tell my students to think upside down. Look at the bottom of the
stone. Use a burr that is the same angles as the bottom of the
stone.
I also always insist that my students de burr the sides of the
prongs where the seat has been cut.
I cut my seat about 40% of the prong width.
Prong setting can be easy breezy once you’ve done a few with proper
setting tools and techniques.
The right way of prong setting is to notch the prongs. The reason
is, when the stone is set on top of the prongs it should sit 1/3 to
1/2 over the prongs so when the notches are cut the stone will drop
in between the prongs and this will also make the prongs bent easy
without putting pressure and stress on to the stone which may result
in cracking the stone.
The prongs that you have seen without the notches are the result of
non professional and mass production without quality. In order to
keep the cost downthe factories hire unexperienced setters and cut
corners. Not notched prongs also tell you that the stones are
smaller then the size required by the piece so a quick squeezing
action with a pair of players on the prongs will hold the stone in
place. This way a factory employee can set hundreds of prongset
stone in an hour.