Freezing green wood sculptures

Elizabeth Wild <lizwild68 [at] hotmail__com> writes

>I am an objects conservator working at the Queensland Art Gallery in
>Australia. Our institution regularly collects sculptures by
>contemporary Aboriginal artists in tropical and rainforest areas in
>Australia. The sculptures are generally made from green softwood and
>then painted with acrylic paints. Splitting or dimensional changes
>are not uncommon in the wood months/years after it is collected.
> ...
>Has anyone attempted freezing similar material? I would be
>interesting in any discussion on this issue.

Depending on how old the green wood is, I would wonder if it still
did have significant moisture in it.  Most of our museum artifacts
do not have enough moisture in them to form ice, but I wonder if
green wood might.  If you have the time, the best option would be to
get some of this "green wood" (possibly from the shop of the
artist?) and put it through its paces.  Take some photos of it
before you freeze it, especially looking at cracks and where exactly
those cracks start and stop and try to gauge how wide they are.
Loosely wrap it really well with tissue or cloth to help control RH,
bag it with good sealing and put it in the freezer for at least a
week. Depending on how thick the wood is and how cold your freezer
gets (hopefully a tissue freezer that can maintain a -20 deg. temp
and not a cycling "frost-free" freezer that does not stay at the
same temp) it might take a while for the coldness to get to the
center of the wood. When you take it out, let it come to room temp
before opening the bag to avoid condensation on the surface.  Gut
instinct, maybe let it sit for two days.  Then take it out and
compare it to your photos.

If you go through this testing process well, you can probably
convince yourself that it is safe to put these items in the freezer.
I know it would be a commitment to go through all that, but there
are a lot of us who would love to hear what happens!  Think of the
service to the profession!  Good luck to you, and e-mail me if I can
help.

Ellen Carrlee


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                  Conservation DistList Instance 17:62
                  Distributed: Friday, March 26, 2004
                       Message Id: cdl-17-62-002
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