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Default Black Walnut - Heartwood/Sapwood Sanding Problem

Still playing with green black walnut (WHAT?!). Am working with
blanks that are half heartwood and half sapwood - half dark and
half almost white. The contrast is quite interesting. But being
a bit impatient (ok - totally lacking in the patience department)
I turn close to the finished thickness and want to see what the
finished piece will sort of look like.

SO - I run through the sandpaper grits - 120 to 320.

BUT - since the wood's still green, some of the dark sawdust gets
on the almost white wood and into it's pores and end grain. The
wood still being "green" that dark sawdust semi-soaks into some
of the white sapwood. Great for finding places that still need
sanding - not so good for keeping the dark/light contrast in tact.

Are "green" turners just a lot more patient than dry wood turners
or are there some methods or means to keep the white wood white
and the dark wood dark - while still green?

Green wood is more fun to turn than dry wood. You can cut
continuous ribbons of wood by the yards. And tools don't seem
to dull near as quick as when turning dry wood. On the other hand,
there's that patience thing as well as the "I have only a vague notion
of what shape this thing will end up with when it finally dries" thing.

Ideas? Suggestions? Caveats? Comments?

charlie b
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Default Black Walnut - Heartwood/Sapwood Sanding Problem


charlie b wrote:

or are there some methods or means to keep the white wood white
and the dark wood dark - while still green?

Green wood is more fun to turn than dry wood. You can cut
continuous ribbons of wood by the yards. And tools don't seem
to dull near as quick as when turning dry wood. On the other hand,
there's that patience thing as well as the "I have only a vague notion
of what shape this thing will end up with when it finally dries" thing.

Ideas? Suggestions? Caveats? Comments?

charlie b

Charlie,
every green wood turner should have a copious supply of shellac on
hand. Use a 1 or 2lb cut. Do a finish cut with sharp tools. Slather on
the shellac and let dry for a couple of days. Then WET sand with oil or
water as a lubricant. Cover the lathe ways and yourself with plastic
first. Personally I use a 50/50 mix of blo and turpentine don't use
paint thinner/varsol as it leaves a white residue in worm holes and
other natural features. Be careful not to sand right through the
shellac. The slurry from the wet sanding fills in small imperfections
and leaves a wonderful smooth surface.
As for distotrion and warping the shellac helps to slow down the drying
and lessens the chance and also helps with cracking.
Peter
Visit my site at:
http://www.oldtoolsshop.com/Galoots/pHyde/

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Default Black Walnut - Heartwood/Sapwood Sanding Problem

Canchippy wrote:
Charlie,
every green wood turner should have a copious supply of shellac on
hand. Use a 1 or 2lb cut. Do a finish cut with sharp tools. Slather on
the shellac and let dry for a couple of days.


Have the shellac flakes and the alcohol. Super Blonde might add a
little pale yellow, which, on the dark heartwood, is not a problem.
But I want to keep the almost white sapwood as colorless as possible.
Maybe Platina will do it. Having a little trouble with shellac and
moist
wood - shellac doesn't normally do well with water and the last thing
I want is to have to deal with gooey wood if the shellac doesn't dry
and cure.

Then WET sand with oil or water as a lubricant.


I'll skip water and go with Mahoney's walnut oil. But the finer
grits
paper for wet sanding are black. The LAST thing I want on the
white sapwood is BLACK.

Cover the lathe ways and yourself with plastic
first.


Finishing furniture doesn't usually involve the finish flying
off the work. Turning -all kinds of things to deal with that
aren't on the list for other types of woodworking.

Personally I use a 50/50 mix of blo and turpentine don't use
paint thinner/varsol as it leaves a white residue in worm holes and
other natural features. Be careful not to sand right through the
shellac.


BLO yellows things too much for my taste and the smell of
turpentine tends to linger for a long long time - not so good
for bowls in which fruits and nuts may reside. Will go with the
Mahoney's walnut oil

The slurry from the wet sanding fills in small imperfections
and leaves a wonderful smooth surface.


Right. But if it leaves the dark sanding dust and oil in the
white wood . . .

As for distotrion and warping the shellac helps to slow down the drying
and lessens the chance and also helps with cracking.


Will try the shellac for the next two bowls and keep my fingers
crossed. OR - I can seal the ends of the green wood I have,
put it in the wood rack out back and try to remember it's there
four or five months from now, then turn dry wood.

Peter


Thanks for the guidance. Appreciated.

charlie b
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Default Black Walnut - Heartwood/Sapwood Sanding Problem


"charlie b" wrote in message
...
Green wood is more fun to turn than dry wood. You can cut
continuous ribbons of wood by the yards. And tools don't seem
to dull near as quick as when turning dry wood. On the other hand,
there's that patience thing as well as the "I have only a vague notion
of what shape this thing will end up with when it finally dries" thing.

Ideas? Suggestions? Caveats? Comments?


You'll have to accept what develops or leave yourself an option to re-turn
for circular. If you've cut it thin, say 3/8 or less, you won't have to
wait more than a week or so to finish. If you cut it thicker, say an inch,
you'll have to wait perhaps two months, at which point you'll be turning dry
wood again, so the fun of green is only half the fun.

You've already noticed that sapwood dyes with heartwood extractives. Same-o
cherry and similar. If you want to keep the sapwood bright, get into the
log early. Otherwise some of that heart color will percolate through. You
will want to protect the bright wood from mildew and the discoloration that
can bring, too. Friend of mine turned me on to compressed air. Even on a
piece you've been spinning for fifteen minutes at 700 there's a lot of free
water available, and the air will bring it out. Inside to outside, since
the inside is under compression as a cross-grain piece dries. Keeps the
wood a couple days shorter in the mildew-making window. Keep your piece in
the open until visible moisture is gone from the end grain. If you bag it
right away, you risk black spots.

Now that you're dry and re-turned or just dry and sanded, don't lose the
bright white you worked to preserve by lathering oil on it.

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Default Black Walnut - Heartwood/Sapwood Sanding Problem

I'm no master turner and am stating it here and now.

But for what its worth, from my experience, turning green and and not
stopping to let it dry is a sure way to get unpredictable results if
you arent as smart as some of the guys here.

On all my green work I turn a rough shape that is approx. twice as
thick as the finished shape I want. To be safe make it 3x the final
thickness. Then you just have to put it aside for at least a week, and
let nature work on it until it's dry.

If you have plenty of blanks you can pick up another blank and start
roughing it to keep you occupied while the former is drying. I have a
few rough bowls I never seem to have time to finish.

Those dry blanks will cut ribbons too, if you have your tool sharpened
well and you apply the tool properly. Dry or wet, long curls come from
proper presentation of the tool.

I will admit, it is quite pleasurable to turn the soft green wood. Its
like a hot knife in butter. With a good tool edge you hardly feel any
resistance at all.

Learning to turn dry blanks will also force you to refine and develop
your turning skills, in pursuit of seeing those long curls spill out
from your tool.

cad
handturnedbowls.biz
charlie b wrote:
Still playing with green black walnut (WHAT?!). Am working with
blanks that are half heartwood and half sapwood - half dark and
half almost white. The contrast is quite interesting. But being
a bit impatient (ok - totally lacking in the patience department)
I turn close to the finished thickness and want to see what the
finished piece will sort of look like.

SO - I run through the sandpaper grits - 120 to 320.

BUT - since the wood's still green, some of the dark sawdust gets
on the almost white wood and into it's pores and end grain. The
wood still being "green" that dark sawdust semi-soaks into some
of the white sapwood. Great for finding places that still need
sanding - not so good for keeping the dark/light contrast in tact.

Are "green" turners just a lot more patient than dry wood turners
or are there some methods or means to keep the white wood white
and the dark wood dark - while still green?

Green wood is more fun to turn than dry wood. You can cut
continuous ribbons of wood by the yards. And tools don't seem
to dull near as quick as when turning dry wood. On the other hand,
there's that patience thing as well as the "I have only a vague notion
of what shape this thing will end up with when it finally dries" thing.

Ideas? Suggestions? Caveats? Comments?

charlie b




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Default Black Walnut - Heartwood/Sapwood Sanding Problem

I have found that wet sanding makes this problem worse, since you can't
control whether the dark or light powder fills the imperfections. OTOH,
some dark wood in the pores of the light wood does bring out the grain
nicely. You might try a high pressure air blast in the sapwood pores to
remove the dark wood after dry sanding & before finishing. That should
remove most of it.

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Default Black Walnut - Heartwood/Sapwood Sanding Problem

Thanks to all for your thoughtful responses.

To summarize for green turning specifically
- sharp tools with proper presentation of the edge
leaves a smoother surface and therefore less
dings/tear out/shredded wood for bacteria, mold,
mildew etc. to begin living in
- turn wall thickness to two two three times the
final desired wall thickness
- "free water", as opposed to "bound water" can be
blown out of the wood with compressed air blown
from the inside to the outside (assuming the grain
isn't parallel to the axis between centers
- sun light and good air circulation discourages
dark mold and mildew growth - but you don't
want to have a hot sun, on a hot day, beating
on the wood as it may dry the exposed areas
faster than the unexposed area, leading to possible
cracks and splits.
- with open grained wood, sanding with oil will create
an oil/fine sawdust slurry which "can" fill the pores,
ultimately leading to a smoother final finish.
- rough shaped green pieces can be dried enough in
several days to a few month, depending on the thickness
of the piece, to be finished shaped and finished "dry"
- if you're going to rough turn green, have enough blanks
to work on while earlier green turnings dry

When turning green pieces with high contrasting heartwood
and sapwood (ie black walnut: heartwood almost black,
sapwood almost white)
- the dark colors will migrate into the lighter areas (steamed
walnut and cherry for example have less contrast between
heartwood and sapwood than kiln dried or air dried walnut
or cherry. the downside is that the colors won't be as
prominent - more towards blah brown than notable grain
patterns)
- it is preferable to turn the piece to its rough shape and
wait 'til it's dry to turn to final shape and finish
- if you're impatient and don't want to wait for the wood to
dry for final shaping and finishing
.. DO NOT SAND when still wet. You'll just drag and then
embed the dark sawdust into the whiter wood
.. if you just have to sand, shellac the green piece first,
let it dry, then sand - carefully so as not to sand
through all of the shellac and repeat the shellacing
between grits, waiting for it to dry before continuing

did I miss anything important?

charlie b
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Default Black Walnut - Heartwood/Sapwood Sanding Problem


"charlie b" wrote in message
...
- "free water", as opposed to "bound water" can be
blown out of the wood with compressed air blown
from the inside to the outside (assuming the grain
isn't parallel to the axis between centers


did I miss anything important?


Do it there, too. Then try to ensure good airflow to the underside by
stickering. Problem develops when the part protected by sitting on
something stays expanded while the unprotected part dries and contracts -
splits. I don't do many "hollow forms," but am advised that even with
limited access through a small opening, stickering is desirable.

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