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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>
<A title=BobDavis88@aol.com
href="mailto:BobDavis88@aol.com">BobDavis88@aol.com</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A =
title=pianotech@ptg.org
href="mailto:pianotech@ptg.org">pianotech@ptg.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> July 25, 2003 1:40 =
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Bridge =
attachment</DIV>
<DIV><BR></DIV>
<DIV><FONT face=arial,helvetica><FONT lang=0 face=Arial size=2 =
FAMILY="SANSSERIF">There are obviously several ways to clamp a =
bridge to a new
soundboard while gluing - pneumatic press, go-bars, screws with their =
holes
later filled with dowels. <BR><BR>Suppose one is using screws. I have =
heard
several people say they don't like to drill through ribs. The old =
Steinways
had a combination of screws through every rib which were then =
dowelled, large
dowels up into the areas between the feet of a footed bridge, =
and screws
through soundboard buttons in the high treble which were just left in =
place.
Is there a better way, if one is using screws? It seems like drilling =
through
ribs weaken the ribs, a hardwood dowel through a thin softwood =
soundboard
between the ribs could break free later and buzz, and a screw left in =
place
through a soundboard button could loosen and buzz, especially since =
many are
inaccessible.</FONT></FONT></DIV></BLOCKQUOTE>
<DIV><FONT face="Comic Sans MS" color=#000080>Drilling through the =
rib does
weaken it. This is not a problem if the soundboard is =
compression-crowned. In
this case the rib is not supporting crown, but resisting it. It needs to =
be some
flexible. </FONT></DIV>
<DIV><FONT face="Comic Sans MS" color=#000080></FONT> </DIV>
<DIV><FONT face="Comic Sans MS" color=#000080>In the case of a =
rib-crowned
soundboard system the rib is a structural member. It is not a good idea =
to do
anything that would weaken the rib right at the point where you are =
putting the
most stress on it--directly under the bridge. </FONT></DIV>
<DIV><FONT face="Comic Sans MS" color=#000080></FONT> </DIV>
<DIV><FONT face="Comic Sans MS" color=#000080>Most of those who use =
screws and
buttons to attach bridges put them in between the ribs, not through =
them.
</FONT></DIV>
<DIV><FONT face="Comic Sans MS" color=#000080></FONT> </DIV>
<DIV><FONT face="Comic Sans MS" color=#000080>It is true that a =
screw left in a
soundboard could cause a buzz sometime down the road. But then so will a =
loose
rib. Perhaps we should leave the ribs off as well. Seriously, enough =
screws have
been left in enough soundboards over the past 150 plus years that if =
this were
going to develop into a severe problem it probably would have done so by =
now.</FONT></DIV>
<DIV><FONT face="Comic Sans MS" color=#000080></FONT> </DIV>
<DIV><FONT face="Comic Sans MS" =
color=#000080>Del</FONT></DIV></BODY></HTML>