Karla, if you have decided that using an adhesive really is the best
way to proceed, then forget about the five minute epoxy. It’s great
when you really need fast set up time, but it suffers from two
problems. Firstly it’s difficult (not impossible, but takes practice
and planning) to get it mixed properly in the time available.
secondly, even when properly mixed, it is nowhere near as strong as
the 24 hour stuff. Applies to all makes of epoxy that I am aware of.
So, get some of the 24 hour stuff. Be carefull to get the correct
proportions of the two components. Although retail packs usually
refer to them as “adhesive” and “hardener”, it’s better to regard them
as two equally important chemicals. In this respect epoxy is totally
different from the polyester-with-peroxide-catalyst systems used with
glass fibre or for so-called cold enamelling. Get something to mix it
on that absolutely will not contaminate your mix with anything, but
especially not with any wax. Clean scrap metal is good … old tin
lids and suchlike. Business cards may be OK. At work I used to use a
large piece of thick Teflon. This contained no plasticiser, and the
cured waste could just be snapped off next day. Such is not easy to
come by, and many other plastics will not be suitable, when you need
to get maximum strength. Finally, have a plan as to just how you are
going to mix the two components. Remember, you have plenty of time,
but the most important point to bear in mind is that your final mix is
rather viscous, and becomes more so, but that molecules that are not
touching cannot react together. I much prefer to mix anything except
very small quantities with two palet knives, or spatulas. One does
most of the mixing, but occassionaly you use the second one to scrape
the first one clean. Let the mix spread out a bit, then from time to
time gather it all up into a central gob, turn it over, and mix again.
As you know, both surfaces have to be clean, and you really need to
wipe with a little alcohol or similar to ensure that. A rough surface
helps too. Apply epoxy to both surfaces, and work it about to be sure
the surface is fully “wetted”.
Finally, be aware that differential thermal expansion may be a
problem with a ring worn daily, and perhaps immersed in hot or cold
water. Minimise this problem by arranging the epoxy layer to be as
thin as possible. Perhaps consider claws or bezel to “just” hold the
piece, with the epoxy as a rigid filler and reinforcement. Or see if
it’s not possible to do aproper bezel setting after all, with no glue.
Kevin (NW England, UK)