Clear adhesives

Does anyone have thoughts on an absolutely crystal-clear adhesive
that would be suitable for bonding glass, ceramics and other objects
where the bond line needs to be and remain very unobtrusive.

Since around 1975, we have used Hysol (or Dexter) 608 Epoxy, which
is crystal clear; however, it sets quickly and is not suitable for
bonding complex projects where some flexibility in the bond lines
needs to be maintained while additional pieces are added. The
adhesive is also convenient, in that it is a tube-kit, consisting of
two tubes, and the mix ratio is 1:1. Other than the speed of cure,
we have had very good results with this product.

For slow setting, we have been using Hysol 0151 Epoxy, which is a
two-tube kit, mixed 2-parts resin to 1-part hardener. This is also
easy to use, convenient, and has a very long set-up time. That's
fine, but the adhesive has a 'straw' color, and does not produce
absolutely clear, unobtrusive bonds.

We'd like to find a good, stable substitute for 0151 simply because
of the color issue. Also, the adhesive should be available easily in
the USA, and needs to be in small kits - perhaps 4-Oz., or so.

Loctite has a family of two-tube products, but they are designed to
mix in an external spiral mixing tube system, which then must be
discarded. Because of this, I haven't tried the adhesives, and would
hope that perhaps Loctite might make them available in kits similar
to the Hysol product line. One of the Loctite products is 530-CL. It
looks great in the syringe kit, but isn't practical to use because
of difficulty in getting it out of the syringe kit and the external
mix issue...

We, of course, are not anxious to change our system, as it has been
highly satisfactory for so many years and we have had no adverse
results with discoloration or bond reliability.

Robert K. MacDowell
MacDowell Restorations


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                  Conservation DistList Instance 15:60
                  Distributed: Tuesday, March 5, 2002
                       Message Id: cdl-15-60-020
                                  ***