Interesting Sap Wood Observation-Drying

Interesting Sap Wood Observation-Drying

Post by Thomas Trag » Mon, 16 Aug 1999 04:00:00



I've been aware that the sap wood of any species is different in
density/make-up than the heartwood, that it drys at a different rate,
etc.

Well, it was interesting to observe something, an unintended "lab
experiment," as it were.

Had roughed out a Cherry hollow-form yesterday at a friend's shop.
He's got a nice, big, new Poolewood 2000, and I had this nice big
chunk of Cherry.  About 10" across and a foot deep.  It's been laying
around for about 3 weeks, had been circular cut from a log, but not
turned yet.

When I got to his place I had thought "no checks yet at all," as I had
checked the sealed end-grain in the bag, and no checks.  Once removed
from the paper bag I could see the whole once SIDE of the blank was
checked pretty badly, and this was the side with sapwood.

So, I have to take a good 1/3 of the thing away to get past the
checks.  Still an OK sized vessel, rough to shape, seal it up mostly,
and re-bag it.

Most of the sapwood had been turned away, except for a splash still at
the bottom, and on one side, mostly on the waste-area just above the
tenon.  I unbag it today to show someone (remember, it's only been ONE
night), and the sapwood has checked & split in about 8 places again!
to either side where it's heartwood, it's solid & clear.

I found it VERY interesting, and a clear, real world example of how
sapwood works/acts differently than heartwood, expecially in drying
properties!

 
 
 

Interesting Sap Wood Observation-Drying

Post by John Jorda » Mon, 16 Aug 1999 04:00:00


Right you are about cherry sapwood/heartwood. I turned a piece a few weeks
ago with just a bit of sapwood around the lip, and it (the opening) was oval
the WRONG way (across the grain) since there was more sapwood that way-It
looked most unusual. It was carved and textured this past week and no
evidence remains. <G> I have been working on a LARGE piece of cherry today
and I really wanted to leave more sapwood around the top, as it was very
nicely patterned, but I know that I'll have problems if I leave it,
particularly in larger pieces.

I'm not aware of any other eastern hardwoods where the heartwood sapwood
vary enough to cause a problem.

John Jordan

Quote:

>I've been aware that the sap wood of any species is different in
>density/make-up than the heartwood, that it drys at a different rate,
>etc.

>Well, it was interesting to observe something, an unintended "lab
>experiment," as it were.

>Had roughed out a Cherry hollow-form yesterday at a friend's shop.
>He's got a nice, big, new Poolewood 2000, and I had this nice big
>chunk of Cherry.  About 10" across and a foot deep.  It's been laying
>around for about 3 weeks, had been circular cut from a log, but not
>turned yet.

>When I got to his place I had thought "no checks yet at all," as I had
>checked the sealed end-grain in the bag, and no checks.  Once removed
>from the paper bag I could see the whole once SIDE of the blank was
>checked pretty badly, and this was the side with sapwood.

>So, I have to take a good 1/3 of the thing away to get past the
>checks.  Still an OK sized vessel, rough to shape, seal it up mostly,
>and re-bag it.

>Most of the sapwood had been turned away, except for a splash still at
>the bottom, and on one side, mostly on the waste-area just above the
>tenon.  I unbag it today to show someone (remember, it's only been ONE
>night), and the sapwood has checked & split in about 8 places again!
>to either side where it's heartwood, it's solid & clear.

>I found it VERY interesting, and a clear, real world example of how
>sapwood works/acts differently than heartwood, expecially in drying
>properties!


 
 
 

Interesting Sap Wood Observation-Drying

Post by George Nazark » Tue, 17 Aug 1999 04:00:00


I am perplexed, because I have never had problems with cherry sapwood
breaking up a drying piece.  I've turned end-grain and face-grain pieces,
heart up and heart down, and often leave sapwood as accent.

With me it is the heart that splits, though some water-thin CA helps a lot.
I don't use plastic bags to dry, though I can't see where that was a factor.
It shouldn't be a lot slower than a paper bag which, when I use one, is my
preference.  I generally just set 'em on the ba***t floor where it's
coolest and dampest for a couple of weeks, then move 'em up the shelf.  No
room on the floor - paper bag.

My only suggestion - leave the bark on until you're ready to put it on the
lathe.

Quote:

>I've been aware that the sap wood of any species is different in
>density/make-up than the heartwood, that it drys at a different rate,
>etc.

SNIP of misadventure with cherry
Quote:
>I found it VERY interesting, and a clear, real world example of how
>sapwood works/acts differently than heartwood, expecially in drying
>properties!

 
 
 

Interesting Sap Wood Observation-Drying

Post by Dick Osbor » Tue, 17 Aug 1999 04:00:00


What George said. I've never had any problem with cherry and I've made
several hundred bowls from it. First you have to cut the pith out of it (I
love to be able to say that without getting into trouble) To get the nice
whitish color from the sapwood that George describes, you most always have
to rough turn it while it is green then dry it (air or microwave), or
complete the turning and accept the warp. Coating the rough turned object
with an end-grain sealer helps. Another advantage of the sealer is with
spalted wood or wood which tears easily. The sealer gets into the fiber and
strengthens it enough to help get a nice clean cut.

--


Quote:
> I am perplexed, because I have never had problems with cherry sapwood
> breaking up a drying piece.  I've turned end-grain and face-grain pieces,
> heart up and heart down, and often leave sapwood as accent.

> With me it is the heart that splits, though some water-thin CA helps a
lot.
> I don't use plastic bags to dry, though I can't see where that was a
factor.
> It shouldn't be a lot slower than a paper bag which, when I use one, is my
> preference.  I generally just set 'em on the ba***t floor where it's
> coolest and dampest for a couple of weeks, then move 'em up the shelf.  No
> room on the floor - paper bag.

> My only suggestion - leave the bark on until you're ready to put it on the
> lathe.

 
 
 

Interesting Sap Wood Observation-Drying

Post by George Nazark » Tue, 17 Aug 1999 04:00:00


That's one thing I quit doing fairly quickly.  I used that stuff from
Woodcraft (~$15/gal) on some cherry and maple, and it leaves the endgrain
darker than the rest of the piece.  I think my problem may have been that
the wood I had was super fresh (day or two), and allowed the wax to run in
farther than I could afford to turn away.

Is it just me, or has anyone else seen this happen?  If so, have you found a
way to avoid it?  I don't have enough losses - and at $55 a full cord,
delivered, most of my turning wood is too cheap - to justify further
experimentation.

 Coating the rough turned object

Quote:
>with an end-grain sealer helps. Another advantage of the sealer is with
>spalted wood or wood which tears easily. The sealer gets into the fiber and
>strengthens it enough to help get a nice clean cut.

 
 
 

Interesting Sap Wood Observation-Drying

Post by Dick Osbor » Tue, 17 Aug 1999 04:00:00


When I turn to finish the object, the outer layer of wood is removed pass
the point of penetration of the sealer so that none of the sealer remains in
the finished piece; less than 1/8 inch.

Just this week I received 4 16" x4' logs of walnut, two burl knots and one
crotch, 4 18"x2' basswood, 6 16"x2' box elder and 8 14"x2" cherry logs, all
felled by a recent storm. These were all delivered for free to my workshop
by a friend, except for the cherry which I had to drive 10 miles to pick up.
This is not unusual for a woodturner in West ***ia. Unfortunately, the
present administration is bringing more logging industries into the state
and old growth, once inaccessible to most loggers, will now be harvested.
--


Quote:
> That's one thing I quit doing fairly quickly.  I used that stuff from
> Woodcraft (~$15/gal) on some cherry and maple, and it leaves the endgrain
> darker than the rest of the piece.  I think my problem may have been that
> the wood I had was super fresh (day or two), and allowed the wax to run in
> farther than I could afford to turn away.

 
 
 

Interesting Sap Wood Observation-Drying

Post by Thomas Trag » Wed, 18 Aug 1999 04:00:00


On Mon, 16 Aug 1999 16:53:23 -0400, "Dick Osborn"

Quote:

>Just this week I received 4 16" x4' logs of walnut, two burl knots and one
>crotch, 4 18"x2' basswood, 6 16"x2' box elder and 8 14"x2" cherry logs, all
>felled by a recent storm.

None of the wood you've described is any good for turning.

You should send it all to me for disposal.

Hey, I'll even do it for free.  Just pay the shipping!

:)

 
 
 

Interesting Sap Wood Observation-Drying

Post by Dick Osbor » Wed, 18 Aug 1999 04:00:00


Funny, Thomas, My brother-in-law said the same thing. I forgot to mention
the ash logs.

Dick


Quote:
> On Mon, 16 Aug 1999 16:53:23 -0400, "Dick Osborn"

> >Just this week I received 4 16" x4' logs of walnut, two burl knots and
one
> >crotch, 4 18"x2' basswood, 6 16"x2' box elder and 8 14"x2" cherry logs,
all
> >felled by a recent storm.

> None of the wood you've described is any good for turning.

> You should send it all to me for disposal.

> Hey, I'll even do it for free.  Just pay the shipping!

> :)