Role of the Staple on a hammer

[erwinspiano at aol.com]

    Dave
    All these concerns are warranted if there is actually tetnsion on the felt. Stwy hammers for example have very little tension & compresion, or at least most of them. The hammers made with the least amount of heat seem to demonstrate the most actual felt tension. Also many hammers are glued these days with radio frequency glue. That's how the hammers get in & out of the press so quickly. I'm not saying that's bad.
  Unless there is a glue failure, hammer seperation in my opinion is very rare. My own opinion is that if the glue doesn't hold it the staple won't be much use. 
    That said I think that a hammer with much demonstratable tension ie. (cut it open & see if it spreads) can exhibit felt creep over time. I challenge any body to cut open there favorite hammers to see this phenomena. Cut the felt open from the top with a razor or bandsaw up thru the molding. I do this routinely for a variety of reason.
  Ronsen hammers have a good amount of tension & Ray prefers to install the staples. For what it's worth I order mine with out. SO there it is. 
  Dale



As I mentioned, I don’t think that the staple necessarily holds the felt to the molding.  The glue itself is adequate for that.  I’ve not seen glue joint failure on hammers with staples pulled and I have seen it on hammer with staples still in place.  I think the integrity of the hammer that Brooks refers to is the tension in the felt.  Over time I have noticed that the staple tends to become more embedded suggesting that the felt expands or wants to release tension in that part of the hammer.  On heavily lacquered hammers the felt is bound together by the lacquer and the hammer is not really a tensioned hammer anymore and this progression won’t happen.  Thus, with Steinway style hammers that are heavily lacquered I don’t think the staple plays a role this way.  Moreover, with the staple removed it is probably a good idea to apply a heavy dose of lacquer to the lower shoulder down in the area where the staple normally resides (Terry).  Don’t let it creep under the crown where it can influence the tone but it’s probably a good idea to bind the felt in that region if it has no other support.  That will remove one’s ability to purposefully release tension from that area by needling which can serve to actually strengthen the crown of the hammer but it’s probably a worthwhile tradeoff.  

 

One other question is just how substantial does the staple need to be to hold the tension in the manner described.  Staples come in all sizes and I wonder how heavy the gauge needs to be to do the job.  Abel and Renner staples are quite heavy.  Steinway staples are not but considering the role of the staple in a Steinway hammer it probably doesn’t matter.

 


David Love
davidlovepianos at comcast.net
www.davidlovepianos.com 


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Barbara Richmond
Sent: Monday, October 27, 2008 9:17 PM
To: Pianotech List
Subject: Re: Role of the Staple on a hammer

 



Hi David,

 

I've taken staples out--only because other people told me I could...and well, I believed them.  :-)   At the CERS this fall, Wally Brooks told a fellow that the integrity of the hammers was destroyed (can't remember his exact words, but he got pretty excited about it) when folks remove staples to control hammer weight.   I figure Wally probably knows something about hammers...

 

Anyway, I'd be interested if anyone had ever had a hammer spring open (some time, sooner or later) after removing the staple.  Guess I'll be crossing my fingers about those staples I've removed in the past--though I think most of them had a bunch of lacquer holding them together.  

 

Barbara Richmond, RPT

near Peoria, IL

 

 

----- Original Message -----
From: "David Love" <davidlovepianos at comcast.net>
To: "Pianotech List" <pianotech at ptg.org>
Sent: Monday, October 27, 2008 9:50:40 PM GMT -06:00 US/Canada Central
Subject: Role of the Staple on a hammer

An older subject but I've been meaning to comment on this.  A few things
have been written about whether the staple is necessary to secure the glue
joint on a hammer.  While I do agree that the glue does most (if not all) of
the work holding the felt to the molding, I think the staple does play a
role in maintaining the overall tension in the felt.  Hammers without
staples must resort to reinforcers (which I have done on occasion) or some
application of heat to stabilize this region.  I think the use of heat to
create stability has a potential downside in that too much will simply
remove tension from the felt rather than reinforce this area in any
particular way.  For that reason, I'm not yet ready to abandon the use of
the staple.
     
David Love
davidlovepianos at comcast.net 
www.davidlovepianos.com







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