Need explanation of terms

[Gordon Holley]

Bill, thank you very much.  There were three individuals that responded. 
 You, Don Rose and Joe & Penny Goss.  My thanks to all for the help. 
 Gordon Holley

-----Original Message-----
From:	Billbrpt@AOL.COM [SMTP:Billbrpt@AOL.COM]
Sent:	Monday, July 16, 2001 2:37 PM
To:	pianotech@ptg.org
Subject:	Re: Need explanation of terms

In a message dated 7/16/01 2:04:23 PM Central Daylight Time,
gholley@hi-techhousing.com (Gordon Holley) writes:


> Hello List.  Over the past months, while reading the posts and exchanges 
on
> the list, I've encountered three terms used in the authors dialog.  I've
> read through two books 1) Piano Servicing Tuning & Rebuilding, by Arthur
> Reblitz, and The Technical Examination, Source Book - PTG, and cannot 
find
> any explanation on the three terms.  Will somebody assist in my search:
> 1. "Burning In" - used in the explanation of hammers and the shank area.
> 2.  "Get The String To Render" - I know what render means, but what does
> the term render mead in this usage?
> 3.

I'm happy to answer these questions for you.

1.  I believe what you mean is "Burning Hammer Shanks".  "Burning in.." is
another term.  Take "Burning Hammer Shanks" to mean, "heating" hammer 
shanks.
 If the wood of a hammer shank has warped from its original orientation,
applying heat to it while twisting it in the opposite direction will cause 
it
to take the bend you desire.  A violin maker uses the heat from a hot plate 
to heat the bow while he puts the desired bend in it.  This is the same
principal.

The word "burn" is simply factory jargon but is commonly understood among
piano technicians the same way "to burn a CD" means to copy one, according 
to
the kids these days.  In the factory, a small alcohol lamp with a candle
sized flame is usually present to do this job.  The flame is used to heat 
the
shank.  It is not necessary to scorch the shank but it sometimes happens. 
 I
think this is where the jargon comes from. We've all blown out the small  
 fire
we've started at one time or another.  Some technicians use a match, some 
use
a barbecue lighter, I just use a common, disposable cigarette lighter for
this purpose.

"Burn in" is a term used in Finish Touch Up or Repair.  A dent or gouge in
the finish can be cosmetically filled with colored lacquer that is melted
with a special, heated knife called the "burn in knife".  The knife is used 
to spread the soft, melted lacquer into the damaged area.

2.  If you simply turn the tuning pin of a string which is low in pitch, 
you
may get it to sound on pitch initially but after a little time or after
playing the key forcefully (which is called a "test blow"), you may notice
that the pitch has dropped back somewhat.  This is because other segments 
of
the string, on the bridge, past the bridge and even those up towards the
tuning pin did not settle their differences in tension by turning the 
tuning
pin alone.

The kind of hammer technique used, the use of test blows and simply the
passage of time will all affect these other string segments.  Getting the
string to "render" means to get all of these nonspeaking segments of the
string to equalize and settle down so that no further change of pitch 
occurs.
 The most difficult "rendering" problems occur with new or newly rebuilt
pianos with very tight pins or in older pianos with rust or corrosion.

3.  I'm a little unsure of what may be meant by "Raking the Hammers" too. 
 I
don't believe I've ever heard anyone say or write that.  The hammer "rake" 
is
the angle the hammer has in relation to the shank.  It may look 90 degrees 
or
perpendicular but it usually will have a small angle off of 90 degrees put 
in
by design.  Small vertical pianos have the most hammer rake.

One of the design or rebuilding experts may be better able to tell you 
about
this but I believe the rake is put into the hammer to cause it to be at 90
degrees when it meets the string.  Otherwise, if the hammer is at 90 
degrees
to the shank, it will do what is called "over center" when it meets the
string.  In other words, the hammer will strike the string somewhere past 
its
center point.

You may have also heard the term used in confusion with Spacing and
Traveling, two other terms that have to do with the alignment of the 
hammers
to the strings.

Bill Bremmer RPT
Madison, Wisconsin
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