Modern paint drying

Gali Beiner <galibeiner [at] hotmail__com> writes

>... I'd
>like to ask for opinions on the length of time one should wait
>before using a display case with an interior that has been painted
>with modern acrylic water-based commercial paints of the type used
>for interior walls in residential homes.

Acrylic dispersion paints normally take about 30 days to completely
lose their water content (at about 50% by volume out of the
container), about another 30 days to coalesce so the acrylic
molecules begin to bunch up and leave less space between themselves
(think of a sphere turning into a marshmallow), and perhaps again as
long before the boundaries between the acrylic molecules begin to
dissolve.  All of these times are environment-dependent--drier
environments will encourage faster resolution.

Water-soluble plasticizers may migrate to the surface during the
drying time and after.  They are easily washed off with plain water.
Whether there is also off-gassing will depend on the manufacturer's
choice of dispersion:  There may be up to 15 different ingredients
in there--each company's is different!

Mark D. Gottsegen
Materials Research Director,
Co-Director, Art Materials Information and  Education Network
Intermuseum Conservation Association
2915 Detroit Avenue
Cleveland  OH 44113
216 658 8700
330 977 0334


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                  Conservation DistList Instance 22:18
                Distributed: Sunday, September 28, 2008
                       Message Id: cdl-22-18-001
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