Improperly sealed imitation gold leaf on paintings

Shelley M. Smith <pixelounge<-at->yahoo<.>ca> writes

>I have a question from an artist about resealing *potentially*
>improperly sealed imitation gold leaf on his paintings created
>within the past 4 years...

My opinion, is based on working as a polymer chemist as a young
person and following the acrylic water based emulsion manufacture as
it was when these materials were made by Rohm and Haas and now
bought out by Dow.

You have an insurmountable problem because no one, not even most of
the chemists at Dow, know the identity of all of the chemicals in
any of the acrylic bases used by artists.  They are purchased by
small art material manufacturers in bulk, and the safety data sheets
my list a few chemicals, but there are vastly larger numbers of
small amounts of chemicals that re never revealed.

First on the list are two biocides :

    Biocides to protect wet paint in the can and which usually
    evaporate

    Biocides which remain in the paints to protect the dry film.
    This is the one likely to still be in the acrylic film.

In addition, water-based latex products may include any of the
following:

    UV (sunlight) absorbers
    adhesion promoters
    anti-sag and settling agents
    anti-skinning agents
    anti-static agents
    antioxidants
    coalescing agents (e.g., Texanol)
    defoamers
    dispersants
    driers (to speed drying time)
    emulsifiers
    flame retardants
    flatting agents
    flow modifiers
    freeze-thaw stabilizers
    light stabilizers
    mar and slip aids
    moisture scavengers
    pH (acidity) control agents
    plasticizers
    rheology modifiers
    rust inhibitors
    surfactants (detergents)
    wetting agents

Most of these are complex chemicals with names as long as your arm.
Many are trade secrets and most have never been tested for their
effects on people--much less effects on artifacts.

You will *never* be able to determine what the minor ingredients in
these products are or what effect they may have when in contact with
a layer of another polymer material whose ingredients also are not
fully disclosed.

Most art works today are conceived experimentally by artists who
have no idea what the chemical ingredients of the materials they use
really are.  They will be restored and protected by conservators who
are almost equally uninformed.  And there is no fix for this.

Monona Rossol, M.S., M.F.A.
Industrial Hygienist
President:  Arts, Crafts and Theater Safety, Inc.
Safety Officer: Local USA829, IATSE
181 Thompson St. #23
New York NY 10012
212-777-0062


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                  Conservation DistList Instance 29:47
                    Distributed: Sunday, May 1, 2016
                       Message Id: cdl-29-47-002
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