(The following adhesive use can be applied to many
facets of jewelry making.)
In my briolette business I often deal with the issue of “glue”. To
be correct, glue is not the proper name for what jewelers might use
in the construction of their products. “Glue” is a protein derived
adhesive made from animal or vegetable products. More advanced
adhesives do not have biological origins like “glue” but are
synthesized in labs and factories using more recent technology. So
to be correct the word adhesive should be used when talking about
modern substances like cyanoacrylates, epoxies, urethanes, acrylics
and others out there.
Briolettes like pearls often rely on adhesives for setting. There
are 3 ways that I am aware of to fix them to jewelry. Two of these
ways rely on adhesives.
see this link for the 3 ways to set briolettes:
I have done testing of these methods and found some very interesting
results. Results which support the use of adhesives over mechanical
methods. In all cases the adhesive setting methods proved stronger
than the mechanical setting methods used to set briolettes. Repeated
tests only proved to substantiate this.
see this link for the strength of the different adhesive and
mechanical settings: http://www.briolettes.com/b_strength.htm
One of the most important and overlooked elements to successful,
strong adhesive bonds is proper surface preparation. Surfaces should
not be polished or smooth but rather they should be rough or
air-abraded when using adhesives. (Air-abrasion is sand-blasting
with things other than sand, i.e. aluminum oxide, glass beads,
silicon carbide, diamond, sand, etc.) The abraded surface not only
has increased area for a bond, but also has peaks and valleys for a
mechanical grip by the adhesive.
Scratching with abrasive wheels or sand paper does not give
equivalent results as air-abrasion. (one look under a microscope
will show this fact). Also scratching induces stresses into the
surface which could cause future failure. Similar to how glass
breaks on the scratch when cutting it.
Surfaces should also be totally clean and grease free.
The proper adhesive is also very important. For jewelry the epoxies
are best in my opinion.
a… they can fill gaps up to .040",
b… they have good shock resistance,
c… can be broken down for disassembly with low heat,
d… come in near colorless transparent,
e… have good chemical and water resistance,
f… have high tensile strength (over 4000 psi),
g… come in a variety of working and cure times to meet the job
I could go on about this, but it would be easier to just look at my
site. It is all there.
Steve Green / Rough and Ready Gems / www.briolettes.com
"now you have a friend in the briolette business" to paraphrase Tom ; )