On Jul 16, 12:20 pm, "Toller" wrote:

1) I could only manage to hollow out about 5.5". And even then I left a little uvula in the middle that I couldn't get out noway. I don't think I can go deeper than 5.5", but how do you get the center part out?

You need a surprisingly substantial tool to hollow 5.5" deep in a
vase. You didn't say what type of tool you were using, or why it or
you wouldn't go past 5.5"

Are you end grain turning (grain parallel with the ways) or are you
bowl grain turning (grain at 90 degrees) to the ways? This would also
make a difference in the tool selection and capability.

Until I was comfortable (OK, sometimes even now...) with my gouges I
used to use my 1/2" X 1" round nose scraper to nibble off that little
cone.

2) I had to leave most of it rough inside because I couldn't manipulate a tool in there, and certainly couldn't get sandpaper in. Any tricks here?

If it is a vase, you should be able to hold sandpaper in your hands it
if it is 4" across and only 5.5" deep. If that isn't comfortable for
you, you can use differnet pliers (I use 12' curved brake pliers),
holders, and homemade gizmos to get the paper to the wood.

3) I nearly lost it because the bottom became extremely uneven when it dried. I did the best I could to get it back on the chuck square, but it wobbled and I had to take more off the outside to get it round than
anticipated.

Very typical. As the general rule of thumb goes, you want to cut to
about 10% of your final thickness. I am more generous than that, but
that 10% allows for radial movement which throws the piece off it axis
of balance when drying. I try to turn as closely as I can to the
final shape stopping at my 10% or so and cut the surface almost as
finely as I would before final sanding when finishing the piece.

But no matter what, when you dry, you should plan to rebalance the
piece when you re-mount.

But looking at your piece and reviewing your dimensions, you have some
other challenges that you will have to master to get things going in
the right direction.

First, a knotty piece of wood like you used, full of occlusions and
twisty grain will never dry perfectly. The more screwed up a piece of
wood actually is makes it more valuable to us woodturners, right? So
that will take some practice and experience from you to make the call
on how close to cut one of these pieces when taking it off the lathe
to further dry. This is one I would have stopped at about 25% of
final thickness and just let it dry longer.

Second, you created a recipe of hardship for yourself when you
hollowed 2/3 of the way down and quit. The wood will dry in a
drastically uneven fashion when parts of it are 1/4 thick (the sides)
and other parts (the base) is about 3" thick. It simply cannot dry
the same way, or react the same way with two huge differences like
that in thickness.

Think about this: The sides can expulse water from both sides making
them dry faster, and more evenly on a smaller thicknes of material
which will give smaller movement. On the solild mass you left on the
base, the water can only leave on the perimeter, leaving the inside
green until it finally dries from the outside in. This can take a
long time and since it is a greater mass of wood fiber and water
drying from one side only, the drying process with distort the wood
much more than an even, two sided drying.

That's my 0.02.

Robert