[pianotech] key bushing problem

[David Love]

Let's be clear because I'm not sure I understand what happened.  There are
two sets of cauls for any particular sized key pin.  The intermediate caul
with which you glue in the first side of the bushing and then the final caul
which you use to glue in the second side.  The final caul is thinner,
usually the width of the key pin plus a few thousandths (don't remember
exactly).  The intermediate caul is thicker because it is designed to glue
in only one piece of felt and so the thickness compensates for the side yet
to be glued in.  If you use the intermediate caul for your final fitting or
to decide what thickness felt to use it will end up too loose.   

 

Aside from that the final caul comes in two types, single shoulder and
double shoulder.  You can use either one you choose.  The double shoulder is
nice if you want to make sure that both sides of the folded over top of the
bushing remain clamped after the final caul is inserted.    Otherwise, you
need to make sure that the glue is totally dry before you remove the
intermediate caul.  

 

So did you use the intermediate caul instead of the final caul for the
second side of the bushing?  If so, that explains why it's loose.  

 

David Love

www.davidlovepianos.com

 

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of John Formsma
Sent: Tuesday, January 26, 2010 8:03 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] key bushing problem

 

Oh yeah, forgot about the different methods. What I wrote was for the single
caul. Haven't used the double.

 

--

JF

On Tue, Jan 26, 2010 at 9:52 PM, David Love <davidlovepianos at comcast.net>
wrote:

You're sure you used the final caul and not the intermediate caul at the
end?  Otherwise, I'm not sure what could happened.  The trial method you
state is the one that works for me. 

 

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