Just musing with no scientific reasoning or experimental backup: Perhaps
the pith itself, doesn't play a causal role in the internal stresses of
drying timber, it's just the area where the growth rings begin. Maybe
the stresses are owing to constricted growth rings due to an intact
drying log or limb or distorted growth rings due to summer-winter
growth, compression-tension reactions or cell
alignment-'dis'alignment wind.

Cutting the rings radially to their beginnings at the pith or that 'one
big longitudinal crack' allows for their free movement tangentially that
would be otherwise constricted with resultant severe stresses. Should
higher Tan/Rad ratios relieve stress and result in less cracking?

What am I talking about, Charlie? I dunno except I think that drilling
out the pith doesn't affect the rings (the real culprits) the same as
relieving their tangential stresses by cracking or cutting radially to
the pith. Whether it's removed or not may not matter as much as we all
believe. You did ask for theories so let the laughter begin!


Turn to Safety, Arch
Fortiter


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