Glue Dots

Renita Ryan <ryan.renita [at] dpc__sa__gov__au> writes

>I am wondering if anyone knows what Glue Dots are made from? And is
>this stuff appropriate for use next to collection material? ...

We informally tested Glue Dots for possible use in display mounting.
We tested the Medium profile, High Shear dots we received as a
sample from the company to use as an alternative to wax to attach
matboard to P-95 acrylic case decks.  (To clean the wax off the
acrylic later required the use of solvents and marred the surface of
the black acrylic.  We were hoping the Glue Dots would solve that
problem.)

I emailed a representative of the manufacturer who described the
Glue Dots this way:

   "Our products have not been tested for either the ODDY or the
    PAT.  We can state that our products are Lignin Free, Acid Free,
    Archival Safe and comply with ASTM-D4236 specifications.  My
    concern would be in the weight of the item being mounted
    vertically. Our products are designed for "light weight"
    applications such as posters, pictures or papers.  Our best
    product for your testing will be our Poster Dots (TM) or our
    High Shear adhesive.  The Poster Dots 1/2 inch Low Profile) are
    available in retail stores and our High Shear products are sold
    through our industrial distributors.  The strength of the
    adhesive would be the same from either channel of purchase, but
    our High Shear is also available in Medium and High Profiles
    (thicknesses).  The High Shear is not the "strongest" adhesive
    we have, but it is the strongest adhesive that would still be
    considered removable.  If your surfaces are flat-to-flat, the
    Low Profile should work for you and is, of course, more
    economical to use.  Here are the thicknesses: Low 1/64 inches
    thick), Medium (approximately 1/16 inches thick), High
    (approximately 1/8 inches thick).  The thickness will not add
    strength but will assist in surface coverage if there is a
    texture or shape involved."

At our lab we Oddy tested the Glue Dot samples and also did a
mock-up display.  The Glue Dots passed two rounds of Oddy tests,
though it was noted that they 'oozed' out of shape (not surprising
with heat, but does indicate that application temperature is an
issue).

We then mocked up an exhibition scenario, applying Glue Dots to the
corners of 4-ply matboard (approximately 11 inches x 14 inches) and
attached it to a scrap piece of acrylic and placed it vertically.
(We also did this with the wax).  The glue-dot-mounted matboard fell
off within several hours (the wax held).  We tried it a second time,
this time thoroughly cleaning the acrylic prior to application. This
time, both the glue dots and the wax held for several months (when
we took down the mock-up).

Some things we noted:  The glue dots were easily removed from the
acrylic and matboard, but did stain the matboard (an oil-like
stain), so they would not be appropriate for use directly on a paper
artifact.  The clean removal of the glue dots, however, improves
'safety' when handling because there's no sticky tape or wax
residues to worry about, and it would allow for possible re-use of
the matboard.

Although we have not instituted a change to Glue Dots (which had
more to do with a change in our exhibition design aesthetic), I
think there is potential for their use as an alternative to wax.
Obviously, more testing would be informative, particularly since
there are several types of Glue Dots with varying tackiness and
thickness.

Emily Olhoeft
Paper Conservator
United States Holocaust Memorial Museum
Washington, DC


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                  Conservation DistList Instance 26:30
                 Distributed: Monday, December 17, 2012
                       Message Id: cdl-26-30-006
                                  ***