Hammer boring fit was: Re: TOOLS/Hide Glue, etc

[David Love]

Yes and no.  Glue generally operates best as a thin bonding layer.  However,
hot hide glue does have good gap filling properties.  Keep in mind, though,
I'm not talking about moving at the joint such that the hammer will fall off
the shank.  I usually bore to exact shank size and ream slightly to fit with
a minimum amount of play.  It would be nice if things were bored exactly.
But as careful as I am, with a fancy Renner boring jig, I still have the
slightest bit of correction to do sometimes.  I don't really consider it a
problem and hot hide glue (not cold hide) fills that small gap very nicely.

The thread also mentioned prebored hammers.  I think it is important to bore
them yourself for replacement.  Steinway has a standard bore that they use
and changes the angle only every 1.5 degrees.  I can't remember a Steinway
that would have matched that standard bore distance exactly and if you want
a smoother fan without reaming, you will have to change the angles more
frequently.

The message in this whole thread is really to bore them yourself.  It's not
hard and not expensive to set up for it.  Also, if you are doing tapering,
you will need to do it before tailing.  Prebored hammers from Steinway also
come tailed.  Prehung hammers are an even worse idea.  Hanging distance will
frequently vary with moving strike points.  All Steinway hammers a glued at
5 1/8".  It won't always work.

David Love

----- Original Message -----
From: "Farrell" <mfarrel2@tampabay.rr.com>
To: <pianotech@ptg.org>
Sent: May 14, 2002 5:23 AM
Subject: Re: Hammer boring fit was: Re: TOOLS/Hide Glue, etc


> I always thought that with wood glue AND with hide glue, a well-fitting
joint is important, and that hide glue does NOT have good gap filling
properties. No?
>
> Terry Farrell
>
> ----- Original Message -----
> From: "David Love" <davidlovepianos@earthlink.net>
> To: <pianotech@ptg.org>
> Sent: Tuesday, May 14, 2002 1:43 AM
> Subject: Hammer boring fit was: Re: TOOLS/Hide Glue, etc
>
>
> > Depends on how wobbly.  Too loose isn't good, but I like some movement
so
> > that I can adjust angles slightly to smooth out the fanning and square
up
> > hammers when boring isn't perfect.  If you use hot hide glue it has
> > excellent gap filling properties and will form a nice collar that takes
up
> > the slack well.  With thinner wood glues a better fit is more important.
> >
> > David Love
> >
> > ----- Original Message -----
> > From: "Greg Torres" <Tunapiana440@cox.ne t>
> > To: <pianotech@ptg.org>
> > Sent: May 13, 2002 6:39 PM
> > Subject: Re: TOOLS/Hide Glue, etc/Isaac Oleg's post
> >
> >
> > > THIS was my main gripe on my previous 'rant' about the Steinway
> > > hammers/parts/...
> > > I also like a hammer bore that is a fairly snug fit. It should never
be so
> > > loose as for hammers to wobble. And for Steinway part's dept. to say
that
> > is
> > > normal just blows my mind...
> > >
> > > Best,
> > > Greg Torres
> > >
> > >
> > > ----- Original Message -----
> > > From: "John Delacour" <JD@Pianomaker.co.uk>
> > > To: <pianotech@ptg.org>
> > > Sent: Monday, May 13, 2002 7:12 PM
> > > Subject: RE: TOOLS/Hide Glue, etc/Isaac Oleg's post
> > >
> > >
> > > > What is a standard hole?  The hammers should be bored so that they
are a
> > > very tight fit on the shank before knurling.  The shank should then be
> > > rolled through the knurling machine to reduce the diameter so that the
> > > hammer can be turned without creaking for about 20 seconds after
gluing.
> > > After that it should become too tight as the moisture from the glue
> > > re-expands the compressed shank.  The hammer should never at any stage
> > have
> > > any wobble, let alone 'fall'!  If the hammers are carefully bored,
hammer
> > > fitting is straightforward provided you follow the proper procedures.
To
> > > have to rely on "wobble" for fore-and-aft positioning is a sign that
the
> > > hammer heads have not been bored properly -- and there is at least one
> > > well-known German hammer maker whose speed exceeds his exactness.  I
> > always
> > > bore my own and save myself a lot of trouble.
> > > >
> > > > JD
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> >
> >
>