I am using an epoxy glue to adhere an inlaid opal into a 14K gold setting (ring). I mix well, let the glue set up a minimum of 24 hours. I do use a tiny (1-2%) color additive especially formulated for fibreglass or epoxy resin. The back of my stone is "painted" with ink from a felt tip pen. I have tried spray enamels, also an epoxy based paint and found them unwilling to hold to the stone. I rough the back of the stone with 180 grit sandpaper before setting, also use a burr on the metal to rough it with cross-hatching. Here is the problem: I have found that some epoxies let go when confronted with common houselhold solvents such as alchohal, or gasoline. Not that my customers are dipping thier hands, but a daily splash with after-shave has been seen to disolve the connection. This was the one we have trusted "epoxy 330." Another I tried has been found to be brittle and to let loose when the band is struck from underneath. I feel there must be something out there that the inlay people are using and happy with? Can anybody point me to what it is and where it can be purchased? Thanks-Larry
Hi Larry, There are several “out of control” adhesives and paints that
we used in military precision optical assembly manufacture when I was
in engineering. Many of them can be purchased by “civilians,” but are
normally not accessible to the average person. Of them, you might
want to try BMS 10-11 Type I (a Boeing Material Specification Primer).
This primer WILL NOT come off of anything - in fact, we had to strip
parts coated with it using heated fuming nitric acid. Nothing else
would touch it. It is what all the jumbo jets are coated with, and it
is bullet-proof. A good adhesive for your opal application would be a
Hysol 0152 adhesive. This may be hard to track down (unless you are a
military contractor), but there is a product very similar used for
assembling custom knifes which is available from K&G Knife Supply in
Arizona. It is called, “K&G Epoxy,” and it is also bullet-proof. I
have never had it fail, even deliberately when soaked in solvents.
This material is available for about $10 in a 8oz, two part kit. They
also have available dyes that can be used to color the epoxy (this is
used in knife manufacture to match handle material colors). Their
number is 1(800)972-1192. The BMS paint can be purchased from Burbank
Paint in California although I no longer have their phone number in my
file (call directory assistance). This paint however is complicated
to use, and must be mixed in parts and allowed to “dwell” before use.
You will also need a spray rig to apply it as it obviously cannot be
supplied in a spray can.