Cleaning art glass windows

In response to Sarah Arehart's inquiry on cleaning art glass
windows, I gave a paper at the AIC Objects Session this June on
cleaning glass.  It will be published in the Objects Postprints
Volume 11, probably in 2005.

Two years ago I ordered some Synperonic A7, and I had to report (at
AIC) that I was not happy with it.  I was happy with the old
Synperonic 'N', and Triton X-100, both now discontinued.  As to
preparation, the instruction that came with my bottle was simply
"Dilute in Water to Use", which is what I have always done with
these concentrated surfactants.  I generally dilute approximately
20:1, using simply a beaker to measure, and not a graduated cylinder.

I have noted, however, that after dilution, the Synperonic A-7 tends
to gel and clump, which is annoying.

In answer to the specific questions:

    1.  As far as I know, the shelf life of the diluted solution is
        indefinite. I have had solutions mixed up for months, and
        except for the "gelling" mentioned above, the material is
        still usable, and is an effective cleaner.

    2.  I have used the solution cold and warm, with little
        noticeable difference.

    3.  Initially, I diluted the concentrate simply in warm water.
        No heating or special preparation was required.

    4.  I believe it is generally irrelevant what water you use to
        dilute it.  I always wash glass in tap water, and follow
        this by thorough rinsing in tap water and then thorough
        rinsing in deionized water.  The last rinse is the most
        important. I have never seen adverse affects on caming, from
        washing, but I generally don't do windows.

    5.  Conservation Resources and the MSDS state that "Synperonic
        A7 is readily biodegradable". I wash, rinse and send it down
        the drain.  It should not be dumped directly into
        streams/rivers. The "drains and watercourses" are these and
        storm drains.  Regular drains send the water through
        treatment plants. The MSDS states that "The product is
        substantially removed in biological treatment processes".

One final comment: In the last 2 years, I have washed over 2,000
objects made of glass with Synperonic A7, and have not seen any
residues or problems. However, I have now switched to using the new
Triton XL-80N, and I simply prefer its handling properties.

Stephen Koob
Conservator
The Corning Museum of Glass
One Museum Way
Corning, NY 14830
607-974-8228
Fax: 607-974-8470


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                  Conservation DistList Instance 18:11
                 Distributed: Thursday, August 12, 2004
                       Message Id: cdl-18-11-001
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