Korean Piano Prepping, was Samick hammer knuckles HARD!!

[atonal@planet.eon.net]

> From:          "Brad Smith" <bsmith006@sprintmail.com>
> To:            "Pianotech mailing list PTG" <pianotech@ptg.org>
> Subject:       Re: Korean Piano Prepping, was Samick hammer knuckles HARD!!
> Date:          Thu, 11 Dec 1997 06:46:45 -0500
> Reply-to:      pianotech@ptg.org

> 
> Roger, Thanks for starting a thread I was thinking of starting! Namely
> Korean piano prepping.  A dealer I work with does not see the value of doing
> this 'extra' work. It
> would be great to have some input from you all about it. Specifically, what
> steps would
> you include on the typical Korean grand out of the crate?  What if you could
> only get the dealer to spring for an extra hour of time? What would your
> highest priorities be?


Brad, 

	This is a re-posting of a message I sent to the list in '95. These 
are some of the concerns that I address on noisy Korean piano 
actions. You need an afternoon, and a fairly well regulated piano 
before you start any of these procedures. I usually set a day aside 
to get a Korean grand regulated and prepped. Depending on the 
dampers, this may extend into the next day. 

Hope this helps, 

Subject: Things that go Clunk  

      Greetings all!  

      As a service technician, I'm called upon to fix *noisy,
      clunking* Imported (read Korean) grand actions. Most of these 
instruments are no  more than 5 years old. Most of these instruments 
are Samick SG series.   
      Simply put, when the keys are released, they return with a clunk
      like   a log being dropped.  
      I've worked out a service regimen to assess this problem.   

1) Keyframe bedding - I've sometimes found the frame glides   
dialled up excessively, or not at all. Fixes some of the clunk.  

2) Balance rail holes are too big - front to back motion in keys.
Sizing   the hole (water-soluable glue, or good old fashioned spit).
Fixes some of   the clunk.  

3) Back rail cloth too dense. Fluff it up with wire brush or needles.
If   done carefully (i.e., not excessively) the key level is
unchanged. Fixes   some of the clunk.  

4) Wip felt (and jack reg. button felt) too dense. Fluffing with
needles   helps, but at the cost of raising the hammer line. Jack
button felt can   be accessed through the rep. window with a needle
held in a pin vise.   Fixes a fair amount of clunk.   

5) Knuckles too hard. I've experimented with replacing an existing  
doeskin knuckle with a Renner doeskin knuckle (slightly smaller, BTW).
  The difference was a considerable reduction in noise. Now, replacing
all   the knuckles would be unfeasable (unless the client wants to
spend the   $$$ "... but I just bought it *new*, why is it having
these problems?")  I've had some success lightly scuffing the knuckle
surface with a brass   wire brush. Nap direction remains unchanged.
Fluffier knuckle = less noise.  

6) Repetition springs too strong. A common problem on brand new
Samicks.   Coupled with dense jack position button felt (the little
regulating   assembly that sets the jack placement re: the knuckle),
this can make a   loud *whack* when the jack returns to rest. Kudos to
Glen Hart   for cutting my time in half on this job. Fixes a little of
the clunk.  

Rob Kiddell                   8-)  
Edmonton, AB. Canada  

... If at first you don't succeed, get a government grant.  
Rob Kiddell, 
Registered Piano Technician, PTG
atonal@planet.eon.net