Rubber cement stains

Kyla Ubbink <kyla.ubbink [at] sympatico__ca> writes

>Miriam A. Kilmer <miriam [at] risingdove__com> writes
>
>>Does anyone know of a safe and effective way to remove rubber cement
>>stains from paper?  Robert C. Morrison wrote in 1995: "To my
>>knowledge, there is no solvent for rubber cement [made from natural
>>rubber]."
>
>... there is a
>commercial product available specifically for dissolving rubber
>cement adhesive called "Bestine". It is basically Heptane and is
>available at artist's supply stores.
>
>...
>Heptane has a great advantages: it does not dissolve dirt and
>therefore does not leave tidemarks; does not require a fume hood or
>suction table; and I have yet to find an ink that is soluble in
>Heptane (although testing first is always wise). I do recommend
>wearing Nitrile gloves when working with this chemical.

Rubber dissolves a bit better in n-hexane. It is currently most
often sold dissolved in heptane simply because this is a safer
solvent than n-hexane.   The difference is significant between a
TLV-TWA of 50 parts per million (ppm) for n-hexane and 500 ppm for
heptane. But rather than say heptane does not need to be applied on
a suction table, I would suggest it be used there anyway.

The TLVs are designed to protect most (not all) healthy adult
workers and most data on which the TLVs are based are from exposure
to males.  Certainly, there is no guarantee for the fetus.  So if
women, pregnant women, or men or women with health issues work in
the lab, the practice should be to use all solvents with air
extraction of some type.  Oh dear, the corollary suggests that
healthy men should go ahead and snort the stuff--that's not what I
mean.  But you understand.

And always check the glove chart from your particular glove
manufacturer. The data really varies.  First, make sure you have
their permeation data, not their degradation data.  Degradation is
when the glove starts to fall apart.  Hell, you can see that.  No
need for a chart.

Second, never accept data from manufacturers that simply rates
gloves as "excellent," "good," "fair," "poor" and "not recommended."

Instead, you want permeation data that is the numerical results of a
lab-run ASTM test which detects the presence of the solvents on the
inside of the glove membrane.  One of my charts says heptane goes
through their nitrile gloves in two minutes, but their neoprene
glove was still holding at 480 minutes (the 8-hour ASTM test limit).
This same supplier's nitrile glove does work for hexane, however. Go
figure.  Better yet, go get a chart or table from your particular
glove manufacturer.

This data is needed because each different type of plastic or rubber
glove can be manufactured using different processes, each of which
affects permeation characteristics.

Monona Rossol, M.S., M.F.A.,
industrial hygienist
Arts, Crafts and Theater Safety, Inc.
and
Safety Officer,
United Scenic Artist's, Local USA829
International Alliance of Theatrical Stage Employes (IATSE)
181 Thompson St., #23
New York NY 10012-2586
212-777-0062


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                  Conservation DistList Instance 26:21
                Distributed: Saturday, October 13, 2012
                       Message Id: cdl-26-21-004
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