Drying pinblock before stringing

[Ken Jankura]

Richard,
Please read my original post again.
To summarize:
Holes in wood act like wood-
High humidity, wood gets bigger, hole gets bigger
Low humidity, wood gets smaller, hole gets smaller
Cross-ply laminated wood does not follow the above rule, and sometimes acts
OPPOSITE, as in:
Pinblocks-
Only the wood cells right around the cut edge of the inside of a tuning pin
hole are able to freely shrink and swell with humidity changes, as the rest
of the wood is constrained by the cross-ply construction. But those
shrinking or swelling cells are enough to make tuning pins-
Looser in winter (dry)
Tighter in summer (humid)

Ken Jankura




----- Original Message -----
From: "Richard Brekne" <Richard.Brekne@grieg.uib.no>
To: "Pianotech" <pianotech@ptg.org>
Sent: Friday, February 28, 2003 9:51 AM
Subject: Re: Drying pinblock before stringing


> Not to fret Cy
>
> You are not the only one to be confused by this. Personally, I could swear
that
> pins get looser in the pinblock during the dry season.... and this
contradicts
> Kens information. But I will be the first to admit that I have never
actually
> gone and put a torque wrench on tuning pins season in and season out, year
in
> and year out to make sure.
>
> All that being said... it would seem to me that the 32 % RH  figure that
our
> tail banging associate waggled around a day or so ago would seem
reasonable
> enough one way or the other. Its on the low end of what is reasonably
acceptable
> variance in RH anyways. Heck.. if all piano room climates never fell below
30%
> RH and never exceed 60 % ...... :) .... but things dont usually work out
that
> stable.
>
> RicB
>
> Cy Shuster wrote:
>
> > OK, I know we've all been over this, but as a newbie associate I just
have
> > to ask.  When we apply an alcohol/water mixture to bushings to free up
tight
> > action centers, doesn't that work by making the wood swell up around the
> > pin, compressing the felt?  And then when the alcohol helps the water
> > evaporate, the wood shrinks back?  (Or do I remember this backwards: do
we
> > do this to bushings to tighten up loose ones?)
> >
> > And wouldn't a one-foot plank of wood get longer (and bigger in each
outside
> > dimension) as it expands, when soaked?  Are you saying the outer edges
would
> > move away from each other, but the walls of the holes would also expand
> > towards the outer edges?  What if you drilled a hole near the edge and
sawed
> > it off through the center of the hole?  Would the straight edge move
outward
> > from expansion, and the curved wall of the hole move inward?
> >
> > Just trying to understand this -- I know it's counterintuitive!  Thanks.
> >
> > --Cy Shuster--
> > PTG Associate Member
> > Rochester, MN
> >
> > > --- Ken Jankura <kenrpt@earthlink.net> wrote:
> > > > Dear Thump,
> > > > OK, one last time, all together now, holes in wood
> > > > act as wood itself would
> > > > act. Fact. Truth. Take it to the bank.
> > > > A FINGER-SIZE HOLE IN WOOD WILL GET BIGGER WHEN WOOD
> > > > IS PLACED IN WATER.
> > > > One note of exception - the hole will initially get
> > > > smaller as water enters
> > > > the wood fibers and cells and spaces by the cut
> > > > edges. But upon equilibrium,
> > > > you'll wonder why you drilled the hole so big.
> >
> > _______________________________________________
> > pianotech list info: https://www.moypiano.com/resources/#archives
>
> --
> Richard Brekne
> RPT, N.P.T.F.
> UiB, Bergen, Norway
> mailto:rbrekne@broadpark.no
> http://home.broadpark.no/~rbrekne/ricmain.html
>
>
> _______________________________________________
> pianotech list info: https://www.moypiano.com/resources/#archives
>