removing key pins

[Elian Degen J.]

This is realy getting interesting, and for our profession it looks very
important to get to the bottom of this

I would inquire deeper on this subject

some interesting sites, and maybe we could write to them for some questions
(I will do it)

http://www.kstr.lth.se/research/Wood/html/wood_res_area.htm

http://www.woodweb.com/knowledge_base/Wood_and_Water.html

http://www.fpl.fs.fed.us/documnts/pdf1994/winan94a.pdf.

http://www.nrc.ca/irc/cbd/cbd086e.html

Elian





----- Original Message -----
From: <JIMRPT@AOL.COM>
To: <pianotech@ptg.org>
Sent: Friday, September 06, 2002 09:05
Subject: Re: removing key pins


>
> In a message dated 06/09/02 8:50:27 AM, elian_degen@cantv.net writes:
>
> << when I take it to my shop first thing I do is get the
>
> humidity level on what I know is the lower in the area I work.  After
>
> hundreds of works I always noticed the same simptoms, and it always worked
>
> right >>
>
> Elian....first pin blocks and plain wood operate differently so lets
separate
> the two and just talk about plain wood.........
>  a screw in wood will get looser as wood dries but not because the hole is
> getting larger...more likely because the taper of the screw has less wood
to
> hold on to as the thickness of the wood decreases......also as wood dries
> hole shapes change from round to  more oval shaped thereby presenting less
> surface for the screw to grip. We force moisture laden wood to compress
with
> our screws and as the wood dries the screw dimensions don't change with
the
> change of dimensions in the wood....also the position of the screw does
not
> change with the change in dimensions of the wood...ergo we have what we
> 'call' loose screws.
>
>  You are correct in your procedure of tightening screws, but you are also
> perpetuating the next cycle of 'loose screws' with a supposed symptom of
> holes getting larger as they dry....... :-)
> Jim Bryant (FL)
>