Balsa or jelutong as filling materials for splits in wooden panels

Yuqi Chock <yuqi.chock<-at->gmail<.>com> writes

>As part of my research, I would like to ask whether anyone has had
>notable experiences (either positive or negative) using balsa or
>jelutong as wood fills, in instances where the surrounding wood has
>little or no space for movement? ...

I am a retired sculpture conservator, and I often worked on objects
made of wood that had cracks.  Unless the crack had made an object
unstable (i.e. vulnerable to break apart), I found it satisfactory
to provide fills made of balsa wood that I adhered to only one
inside surface of the crack.  This is of course not a structural
repair, just a safe way to make the crack less obvious.

One must always expect that at some time, even in a highly
climate-controlled museum, there might be an occasion (like a leak
in the building) when the ambient humidity becomes very high.  Using
balsa wood as the fill for a cracked sculpture made of stronger wood
ensures that later, if/when high humidity causes the crack in the
sculpture to close somewhat, the soft balsa fill will suffer
compression "sacrificially" instead of the harder original wood. And
when the ambient humidity is reduced, the crack-with-fill will
reopen neatly along the side that is not adhered to the crack.

Good luck with your project.  I'll be interested to know the results
of your research.  In the late 1970s or so, I attempted doing
empirical research to compare a variety of flexible filler compounds
for possible use on wood objects.  However it proved too difficult
and time-consuming to complete my project, which required keeping
detailed records of months of precise measurements of many blocks of
wood with inserted fills.  As I recall, about the same time
conservators at the Canadian Conservation Institute (CCI) launched a
similar project.  You might consult someone at CCI about their
long-ago research, which I believe resulted in a published article.

Jean D. Portell
13 Garden Place
Brooklyn, NY 11201


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                  Conservation DistList Instance 29:4
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