I am amazed that this thread became anything about tumbling
cabochons.
It seems to me that tumble finishing cabs is too unpredictable.
Nothing like the control one gets by doing it by hand.
And now, a further diversion within this thread…
I generally set cabochons in closed-backed settings and faceted
gems in open-backed settings
You can do what you want, but that’s not a good rule. A better rule
would be, and I’ve said it before…
…Set opaque stones in closed-backed settings, and
transparent/translucent stones in upon backed settings.
Transparent/translucent cabochons don’t benefit from closed backs.
I am not a supporter of foiling because I don’t endorse the use of
glues in finished jewelry products. I make an exception to doublets
and triplets because I accept them in the industry, but do not do
them myself unless hired to do so by a customer (that’s also how I
treat diamonds, I set them only if requested by a customer).
And now about the topic.
When I facet I use Super Strength 5 min Epoxy, the white/blue two
part I think is made by DevCon. Any other 5 min epoxy is unwise for
this application. When transferring I back the stone off the dop a
bit (if doing a round) to allow more epoxy between the stone and the
dop because I’ve found If I do this it will eliminate the vacuum that
can happen. This vacuum makes it difficult to pop the stone after
it’s done. Then you will have to use something horrible like Attack
or Methyl Ethyl Ketone to break down the epoxy and, because of the
vacuum, it will take even longer for the solution to penetrate the
epoxy. The stone should be cuttable in 3 hours but I often wait over
night.
Any epoxy facetor out there experience this vacuum? I had this
problem quite a bit until I figured out that I shouldn’t have the rim
of the dop touch the stone.
I thought I followed this post all the way. Has anyone mentioned the
use of heat to liberate stones from epoxy dops?
And lastly, I don’t use dop wax at all. I became tired of being
burned. Also, if my shop freezes I have to re-do all the wax dopping
and that isn’t fun.
TL Goodwin
Lapidary/Metalsmith