There is a method I have done thought experiments on, in which a wood
part could be soaked through with methyl methacrylate monomer, which
will penetrate to the deepest cell structure, and then activated
chemically to cross link. Something of this nature could possibly be of
use. Methyl methacrylate monomer will cross link under UV such as
direct sunlight, which I have used (taking several days to start the
reaction). You would need to maintain the saturation in a closed
container since the monomer is quite volatale.

A.L.
Phoenix