"Prometheus" wrote in message
...
Sorry, but what does TDT stand for? I'm guessing that it needs to be
thinner in the bottom and top when hollowing into end grain, to keep
the pith as thin as possible?


Turn,dry, turn. The end grain area is the fastest to lose, but also the
easiest to gain water, so you want to give it the least "hold-on" help. It
pulls against something else, so don't give it too much to pull against, and
it may not pull apart.

Does applying the finish in the same session do the trick, or do I
need to try something else, like the paper bag full of shavings
method?


Applying a finish does not dry the piece. It may slow moisture loss, but
when the piece gets below the FSP (Fiber Saturation Point), the cells walls
will thin and the piece shrink. Not conducive to good fits. Drying it
slowly in a bag, newsprint, or such is your money move. Shavings have
lignin, and may promote mold.


Do you mean roughing the blank slightly off-center to begin with, to
keep the pith oriented at an angle, or just making sure that the
exposed pith is on an angled feature of the piece? Come to think of
it, either may work- right?

It's the don't give much to pull against move all over again. With the pith
located in a sloped or curved area of the wall, it has less to grab below,
because there isn't enough continuous fiber across the grain. Little loss
(1%) of dimension along the grain.