Pigment binder

Zack Peabody <zackofalltrades<-at->yahoo<.>com>

>I have been volunteering in the National Parks, gently sandblasting
>spray paint graffiti from granite then touching up the damaged
>pre-existing natural mineral stains by airbrushing with mineral
>pigments and water, and was looking for suggestions for a non-toxic
>airbrushable binder for mineral pigments that won't attract microbes
>or other flora.

I am assuming that the graffiti is a fine pigment (not a dye) that
has penetrated into the matrix of the granite (not sitting on top)
and that it is not possible to remove the defacement by poultices,
solvents or other less invasive techniques.

You may try and use dilute sodium silicate in water as a binder for
the pigment you want to apply.  It will penetrate the stone and once
set, it will become insoluble in water.  I is not organic and will
not promote microbial growth.  Over time it will become somewhat
less transparent and rough, approximating stone.

Experiment on disposable surfaces before doing anything critical.
Good luck,

George Schwartz, Professional Associate AIC
ConservArt, Inc.
561-482-7292
561-912-0030
Mobile: 561-206-4406
Fax: 609-594-1199


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                  Conservation DistList Instance 29:7
                   Distributed: Friday, July 3, 2015
                        Message Id: cdl-29-7-003
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