Dead Bass Strings

[John Delacour]

At 23:42 01.11.95, EHILBERT@middlebury.edu wrote:


 |: I too have heard that bass string should be put on soon
 |: after being made. On the other hand, I had a set made one
 |: time for a Marshall and Wendall grand.  Then the project got
 |: set aside and I finally got back to it probably ten years
 |: later.  I decided to try the strings and they sounded just
 |: fine.  I certainly have had other sets for much longer than
 |: 30 days which also sounded fine when finally installed.

I recently supplied a customer with a set of bass strings that I had made=
 five years ago for an identical piano that I have since shelved,  There=
 were no complaints.  Nevertheless I myself would always install strings as=
 soon as possible after manufacture.  The realignment of the molecules in=
 both the copper and the steel is slow process and it seems logical to allow=
 this process to happen with the strings installed.

 |:          My suspicion would be that there would be a
 |: tendency for the core wire slip back inside of the
 |: winding if left too long without tension. Remember, the
 |: string is made on the string winding machine under
 |: considerable tension. I forget the exact amount but sort
 |: of recall a figure in the range of 70% of the tension when
 |: pulled to pitch on the piano.  Obiously, if the core wire
 |: then slipped back inside of the winding, when the string
 |: would then be pulled up to tension, it would tend to open
 |: the windings and that would not be desireable. I too
 |: shall wait for a more definitive answer.

Several points here.  The tension used on the winding machine must be less=
 than the tension at pitch for various practical and tonal reasons.  Two=
 things happen when the string is removed from the machine:

1.  The coils move a minute amount towards each other or, put another way,=
 they are slightly compressed longitudinally.  If the flattening at the ends=
 is adequate, this compression will be held and no creeping of the covering=
 will occur any more than it will occur when the string is brought to pitch=
 on the piano.

2.  When the end of the string is released from the grip of the machine=
 chuck, the residual tension in the copper wire twists the string.  This is=
 why it is important to twist strings when they are installed on the piano=
 and further twisting (more than is needed to restore the untwisting upon=
 removal from the machine) is generally recognized to be advantageous.

Most significant is the molecular rearrangement of the strings.  You will=
 all have noticed that a replacement string can sound less good than its=
 neighbours when first installed and yet blend in perfectly after a month. =
 Not only that but we are taught at school that a wire stretched within its=
 elastic range will return to its unstretched length when the tension is=
 removed, but experience teaches us that this is not so and that the string=
 continues to drop in pitch for some good while after installing although it=
 has never been stretched to its elastic limit.  These two phenomena go hand=
 in hand and are due to the slow redisposition of the molecules in the steel=
 wire (and in the copper) until they are comfortable in their new stretched=
 state.  When the string will hold its pitch for months on end you can say=
 that it will not improve any more in tone.

                John

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