Need explanation of terms

[Billbrpt@AOL.COM]

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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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