Bubble wrap and water damage on acrylic paintings

Recently, a four-part series painted by a young indigenous person in
2004, was received in the laboratory for treatment. The works are
mixed media, and include applique hessian (charred) with bleach
mark,  adhered with PVA glue onto chinese manufactured acrylic
ground cotton canvas and stretcher.  The artist splashed both black
and white acrylic based paints onto the canvas around applied burnt
hessian, making a mixed media drippy composition.

In February the paintings were damaged due to flash flood/rainstorm,
which prolonged wetting of the surface of the stored paintings. The
bubble wrap surrounding the paintings was left in contact with the
surface for approximately 36 hours.    The contact between surfaces
resulted in tide marks and bleeding out of the black paint,  making
very disfiguring blue/black staining in a bubble wrap pattern on
both the acrylic ground layer, and the cellulose of the cotton
canvas.

Wet cleaning removed a great deal of the superficial colorant,
however there are large stained areas remaining on both the painted
acrylic, exposed cotton canvas.   I have tried many options for
reducing the staining and am looking for advice as to what might be
the best and most conservation sound option to use to decolourise or
alter the double bond of the blue black colourant,  (which is likely
to an aniline dye molecule,  not a pigment based paint)

I am aiming to reduce the tide mark staining on the acrylic ground
and canvas as much as possible.  The artist has agreed to repaint
the very damaged sections post treatment, in consultation with the
owner.

Caroline Fry
Painting Conservator
The Centre for Cultural Materials Conservation
The University of Melbourne
99 Shiel Street
North Melbourne 3051
+61 9 348 5700


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                  Conservation DistList Instance 24:45
                  Distributed: Monday, March 28, 2011
                       Message Id: cdl-24-45-026
                                  ***