I work with lots of different adhesives (lapidary) and maybe I can
help. Here's some things to remember:
The cyanoacrylates actually need moisture to set and cure. Cleaning
the pieces to be joined with 91% isopropyl alcohol (never acetone)
then breathing on one piece just before applying pressure assures a
solid join, but is usually not necessary. However, the
cyanoacrylates are somewhat sensitive to shock, so a sudden rap can
break the bond on the older formulations. Loctite's new
"Professional Grade" seems to create a very, very strong bond which
is NOT shock sensitive, and easily withstands heat to 350 F plus.
But the glue is not flexible at all, so shouldn't be a first choice
for your application. While you can use a thicker cyanoacrylate with
an accelerant, it weakens the join 30-50%, according to Loctite and
The 2 part epoxies are not very flexible, if at all, when cured, and
WILL break down in the presence of high humidity or water. Takes
some time, but they are not reliable if water is involved, including
the shower, trust me, been there and done that!
There is an adhesive from Norland Adhesives, that is clear and cures
with either UV (sunlight works fine) or heat. And as the cure
continues (it joins very quickly but continues to increase in
strength for many days), if glass is involved, the adhesive actually
penetrates the glass surfaces and becomes one with them. This bond
cannot be broken, but is not flexible.
The silicones mentioned, especially the 3M product, will create a
clear (available in clear, white and black) and flexible bond which
is quite waterproof. It would be my adhesive of choice for the job
If you Google Loctite and Norland Adhesives you will find vast
on all kinds of adhesives. Considering that many can
withstand heat in excess of 400* F and have a tensile strength
exceeding aluminum, I'm surprised we don't see wider use of them in
the jewelry world. Old prejudices, I guess.
Hope that's of some help...I am a long time admirer of your