Wood & Humidity, was Hammers

[Farrell]

> "OK ?"

OK.......but! Are we really sure that a varnish/laquer covered spruce panel
would absorb more moisture than an unprotected piece of
maple/hornbeam/walnut (or whateverelse and action is made of)? Certainly the
large panel would change dimension TONS more because of its overall size,
but per unit volume, I would almost be suprized to find that it does. (I'm
trying to be constructive and informative - not step on anyone's toes!)

Is this a question for Del to chime in on?

Terry Farrell
Piano Tuning & Service
Tampa, Florida
mfarrel2@tampabay.rr.com

----- Original Message -----
From: "Tony Caught" <caute@optusnet.com.au>
To: <pianotech@ptg.org>
Sent: Saturday, December 30, 2000 9:36 PM
Subject: Re: Wood & Humidity, was Hammers


> Hi Terry
>
> Gee wiz and golly gosh. My mistake I should have been more explicit and
said
>
> "Both spruce and pine that are used for making soundboards are soft
timbers,
> cut on the quarter which promotes swelling of the soundboard.  These soft
> timbers will of course accept moisture more rapidly than the hard woods
that
> are used in the making of actions in the same piano."
>
> Am not into timber boat building, only interested in pianos and aluminium
or
> fibreglass boats but thanks for the info.
>
> PS I guess I should also make a correction to the above by adding that
> "Other timbers have also been used for making soundboards with varying
> degrees of success however the varieties of the above mentioned timbers
that
> are used, today, for making soundboards, are of the softer variety".
>
> OK ?
>
> Regards
>
> Tony Caught ICPTG
> Australia
> caute@optusnet.com.au
>
> ----- Original Message -----
> From: Farrell <mfarrel2@tampabay.rr.com>
> To: <pianotech@ptg.org>
> Sent: Sunday, December 31, 2000 3:16 AM
> Subject: Wood & Humidity, was Hammers
>
>
> > >" Both spruce and pine are both soft timbers, cut on the quarter which
> > > promotes swelling of the soundboard.  The soft timbers will of course
> > accept
> > > moisture more rapidly than had woods."
> >
> > I don't think the above statement is necessarily true at all. Both
spruce
> > and pine are "softwoods". All spruce and some pine woods are soft. Some
> pine
> > woods are extremely hard. Some "hardwoods" are soft and some are hard. A
> > "softwood" cut at a time when much resin is present in the wood may make
> the
> > wood less susceptible the water content gain from high humidity.
> "Hardwoods"
> > can vary to extremes on their ability to pick up moisture from the air -
> > largely based on their cell structure. Trees have interconnected cells
> that
> > allow water movement from the roots to the leaves. These cell can large
or
> > small diameters. Also, upon a cell's death, the cell ends may close or
> open
> > up. A species group such as red oak (certainly a very hard "hardwood")
has
> > both large interconnected cells and the cell ends are not present after
> cell
> > death. Cut a six-inch long piece of red oak. Put your mouth up to one
end
> > and blow. You can feel the air coming out the other end (or dip one end
in
> > water and you can make bubbles!). Certainly these kinds of structures
open
> > up such a wood to rapid changes in moisture content. The white oak group
> on
> > the other hand has little end caps on each of the same cells, thus
> > preventing water from flowing through the wood. That is why they make
oak
> > wine and whisky barrels out of white oak - because liquids will not pass
> > through. These are some of the properties that give white oak many uses
in
> > boatbuilding and make red oak a big No No in virtually any boatbuilding
> > application.
> >
> > Terry Farrell
> > Piano Tuning & Service
> > Tampa, Florida
> > mfarrel2@tampabay.rr.com
>
>