Could someone point me to some advice for the correct technique
for setting stones in channels, as, for example, in eternity rings?
I'm taking far too long to complete these - the main problem being
getting the stones to stay put while the edges of the channels are
burnished over. I suspect that the correct preparation of the
channel is critical.
Correctly fitting the stones in the channels amounts to cutting seats
that correctly support the stone, and do so in the right postion (as
in, all level, and the correct height, etc, and without the seats
being too loose or the like. Seating the stones will, once you get
good at this, take longer than any other part of the process. Once
they are properly seated, burnishing/hammering over the edge and
finishing the setting is relatively quick.
Once they are properly seated, most setters I know, if they are
hammering/burnishing over the channel on more than a few stones at a
time, will hold the stones in place with a bit of soft wax. The red
"boxing" wax often used for spruing works well. “wipe” a bit of the
wax onto the stone, so it bridges the crevice between the girdle of
the stone and the metal of the channel. Then briefly brush the flame
of your torch over the wax. The stones will heat enough so the wax
melts, and flows down under the seats and stones, making what you’re
working on, the channel, again clearly visible. But the wax,
underneath the stones now, still holds them just fine. This is most
suited, of course, to diamonds, but works with any stone where the
little bit of heating you apply to melt the wax in, doesn’t endanger
the stone. You DO need to be sure the channels are properly set over
the stone before you clean the wax off (a steam cleaner, or boil it
out), since if the stones are not properly seated and set, they may
not move around and appear loose, yet then can slip out when you steam
off the wax. But if they were correctly seated in the first place,
this won’t be a problem.
If you’re only setting one or two stones, well, then I’ve found a
fingernail held over the stone while I work often is enough. Other
times I’ve just used a little bit of string or a strip of plastic cut
from a zip lock bag (always a few of them floating around the bench),
stretched along the row of stones between the walls of the channel.
But holding these down tight on the stones sorta means you then need
extra fingers, so the wax is usually easier.