Filling termite galleries

Daniel Cull <daniel.cull [at] themim__org> writes

>I am currently treating a wooden object from Papua New Guinea, that
>has damage from termites.
>
>I am looking for a method of filling the termite galleries in such a
>way that they will provide structural support for the now fragile
>overlying wooden surface. The fills need to be structural because
>the object will be on open exhibit, so more simple cosmetic repairs
>will not suffice.

I have successfully filled/strengthened sub-surface insect cavities
by first saturating the damaged wood with a 5% solution of Butvar
polyvinyl butyral.  This is alcohol soluble, generally does not
darken like other resins and makes the wood water resistant.  I then
make a slurry by grinding cellulose powder or shredded acid free
paper into a 1 or 2% solution of carboxy methyl cellulose, tinting
with pigments if the fills will be visible anywhere.  The paste,
when mixed thoroughly enough can be injected into cavities through a
syringe.  The voids should be completely  filled and allowed to dry
(takes a few days).  When dry, the cellulose coats the interior of
the cavity walls and hardens to a surprising degree.  Repeat
injections may be necessary.  Surface voids may be filled with a
thicker paste and  in-painted.  Residues can be removed with a damp
swab.  Obviously if there are paints that may be damaged by contact
with alcohol or water, this would not be a good choice.

This supports fragile surfaces very well without contracting during
drying, but will not make it as strong as the original wood, so if
you mean that it must be structural enough to hold up hundreds of
pounds, this would not be your method.  For structural fills that
must hold weight, the carve-able epoxies are a better choice, but
obviously completely irreversible, harder to inject and less
compatible with the wood.

Linda Roundhill
Art and Antiquities Conservation, LLC
Woodinville WA


                                  ***
                  Conservation DistList Instance 23:19
                 Distributed: Sunday, November 29, 2009
                       Message Id: cdl-23-19-004
                                  ***