[CAUT] Hammer Alignment

[David Love]

I would have to agree. Heating the glue joint seems to be asking for trouble
with both Titebond and hide glue (which I still use).  

 

David Love
davidlovepianos at comcast.net 

-----Original Message-----
From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Gary
Mushlin
Sent: Wednesday, March 29, 2006 8:07 AM
To: ed440 at mindspring.com; College and University Technicians
Subject: Re: [CAUT] Hammer Alignment

 

I used to heat the glue joint to align hammers, until I found out that
Titebond begins to break down at about 120 degrees, and loses half its
strength at about 150 degrees. I got this info from a technician named Tom
Patten in his class concerning fire damage to pianos. My understanding is he
got this information from Franklin, the makers of Titebond. I assume this
applies to other glues as well.

 

Maybe this isn't enough loss of strength to affect the hammer glue joint
significantly, but I'd rather not take the chance. I now twist the shank, as
was described in a previous response to this question. If the hammer is too
far off to twist the shank, I remove the hammer and reglue with fresh glue.

 

Sincerely,

 

Gary Mushlin, RPT

 

 

On Mar 29, 2006, at 9:16 AM, ed440 at mindspring.com wrote:






I will second Wim's approach.

I heat the glue joint with an Ace hardware heat gun on low setting, moving
from side to side of the hammer.  If correcting more than one hammer I will
move around and heat several at once.  You need to give time for the heat to
penetrate to the glue, and you don't want to make charcoal.

Then grasp the shank with shank knurling pliers just below the hammer.  No
stress on the flange pinning, and very definate control.

Then reset the hammer sort of like setting a tuning pin, over and back a few
times until it's on center.

I use Titebond in my work, but have also used this method on pianos with
what-ever-it-is glue. Results seem stable, but I have not made a research
project on the question.

 

Ed Sutton

  _____  

Original message
From: Wimblees at aol.com
To: caut at ptg.org
Received: 3/28/2006 2:11:50 AM
Subject: Re: [CAUT] Hammer Alignment




In a message dated 3/27/2006 11:13:17 PM Central Standard Time,
davidlovepianos at comcast.net writes:

Do they always end up twisting in the same direction?  One thought is that
if you burn the shanks for straightening at the initial installation and you
hold the heat gun, say, in your right hand, you might be heating one side of
the shank more than the other which might create some unequal tension in the
shank that might play out over the period of a few weeks or months.  

I have been reading these post with interest. I seem to be getting the
impression that some of you are heating and bending the shank to move a
hammer. I personally think that might be causing the problem Jon first
mentioned. It has been my experience that the best way to burn hammers is
heat the glue joint enough to allow me to twist the hammer. I then hold the
hammer in its new position for the glue to solidify. I have never had a
hammer move after that. I don't think the heat does any damage to the glue.
I use Tightbond, BTW. 

 

Wim 

 

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