STRING REPLACEMENT
As all harpsichordists know, strings occasionally break.
They do this for a few reasons, the most frustrating of which (especially for
someone new to owning a harpsichord) is tuning the string next to the one you
are sounding; and yes, we’ve all done it. Other reasons are: in the case of
brass wire, old age (brass hardens with time) or the string winding at the wrest
pin grinding its way into the wrestplank - there should be a bit of a gap
between coil and plank but this is diminished with repeated tuning or by tapping
the pin in to be firmer; and strings do break for absolutely no apparent reason.
You should know what wires are on your harpsichord, and their diameters. However
not all makers give this information with the instrument, or the information
has been lost. Measuring the diameter of adjacent strings is often necessary.
Identifying the material is essential, because most modern instruments made
before 1980 are designed to use steel music wire in the treble, often at
tensions impossible for reproduction iron wires to withstand. In the period up
to about 1980 the steel treble strings were accompanied by modern brass and for
the extreme bass sometimes phosphor bronze or even beryllium copper was used.
Re-introduction of authentic wire is now almost universal; the iron is softer
than steel, and the less pure brasses, yellow and red, are far stronger than the
earlier alternatives. Most makers and technicians should be able to make an
informed guess about what was used from knowing who made the instrument and
when.
Wires need loops made to hook onto the hitch-pins. Making these is a skill. I
have strung many instruments using a curtain-wire hook in the chuck of a
hand-drill, which was mounted in a vice and turned by a helper, or held between
the feet and turned with one hand while holding the wire in pliers with the
other - not recommended for anything but steel wire..... I’d hate to have to
make loops any more, and in any case this can’t be done with reproduction wires,
they will work harden and break.
Far better is to buy wires properly looped by a maker. It is important that the
loop is made without stressing the wire too much, so the wire while being
twisted around its’ self (at around 18rpm using my electric device) is allowed also to twist about its’
own axis; this takes practice. There is an ugly short self-locking loop that is
easier to do, found on some kit harpsichords. You should really use the style
that has been used for the other strings. Hand operated string winders are
available from Vogel (www.vogel-scheer.de)
Equally it is important to treat the wire with great care in order that no kinks
are formed while fitting the string. Any kink will be audible as an odd
uncertain flavour to the sound which does not make tuning very easy, and never
goes away. The wire should have no twists along its length
either; they too can be heard.
There is little consistency regarding tuning pins. Most of the ‘revival’
harpsichords have ‘zither’ pins. These are around 4.75mm (3/16”) in diameter,
rather larger than those used on antique harpsichords, and have square heads;
these are cross drilled for the string, and have a lightly milled ‘thread’ on
the bit you don’t see, which means that you can extract them by turning them
anti-clockwise with the tuning key, although it takes ages.
Old instruments have the head formed by flattening with hammer blows, and the
shafts, which vary in diameter from about 3.5mm to a maximum of 4.5mm are
usually but not always tapered where the pin enters the wrest plank. Two or
three diameters are often found across the compass, the larger used in the bass.
Good reproduction instruments will use similar pins. Removing them can be
tricky. There is no threading to help you; tapered pins usually come out easier
than parallel ones, but both sometimes resist the ‘twisting and pulling at the
same time’ technique using the tuning key. A small pair of ‘mole’ grips with the
serrations smoothed off is much safer than using pliers, since slipping is to be
avoided. The pins on old instruments are not drilled: as soon as the iron used
for the pins was pure enough to be largely free of hard unexpected inclusions,
and as soon as drill bits were tough enough at these small sizes, they were
drilled, but this did not become common practice until just before the
nineteenth century, with the factory production of pianos. The soft wire used
for harpsichords holds easily with no hole in the pin, but most pins available
commercially now will be drilled. But many makers still make their own pins and
mostly these are not drilled.
Pins can become too loose; each restring with any parallel sided pin making the
fit a little looser, and although the tensions of strings are not high (2 -7 kgf)
a pin that is too loose is as difficult to tune as one that is too tight. such a
pin can be safely tightened by slipping thin card, 1-2mm wide, down the hole as
you refit the pin; just ensure the card is left or right of the pin, not in the
string direction. A technician may use very slender strips of wood, sometimes
with a smear of glue, as a more permament solution. On an antique instrument a
few drops of hot water from the gluepot may swell the wood and do the job.
When the string loop has been fitted to the hitch-pin, slight tension must be
kept on the string all the time you are fitting it to the pin; Longitudinal
twists must not be present, so the wire is held gently in the fingers near the
hitch-pin and drawn along the wire so that any twists are allowed to disappear.
Iron or steel should at the same time be wiped, so use a small bit of cloth in
the fingers.
Some few people are unfortunate in that their skin exuded something that
instantly corrodes wires; If you are afflicted you have to wear cotton gloves. I
once was visited by some-one who loved to touch things and he ran his hand
across the entire string-band of a new instrument, and within a few minutes a
series of black lines appeared across the nice shiny new strings, which had to
be polished out immediately; It’s something to do with ammonia; brass
instruments of antiquity can sometimes be strong enough when found to be played
but others cannot be removed safely from the earth; an archaeologist told me that
the failures were unfortunate enough to be buried where the chicken run had
been.
OK. That’s the introduction over. Now for the practical bit. You need tools: a
tuning key and if the key has an metal strikers on the ends of the handle (hence
the alternative name ‘tuning hammer’) you will need a hammer too, a small one is
OK if you are sure of your aim, since little force is required, but one with a
medium sized head makes it more difficult to miss the pin. A pair of small wire
cutters are useful, and quite essential ( as are a pair of 5” pliers, the teeth
in the jaws having been smoothed carefully) if you are having to fit steel wire,
and if you are making your own loops on any wire. For removing stiff tuning
pins, a small pair of prepared mole grips will be useful. Have the hammer where
you can reach it, not on the floor or the other side of the room, since you will
need it to hand while you are keeping tension on the wire and the coils around
the tuning pin.
Ok, you have a broken string; remove the jack rail. Locate and remove the bit of
wire that used to be attached to the hitch-pin. Find the tuning pin and remove
the string still attached to it, if it still is. Now remove the pin:
If the pin is square headed, turn the pin anti-clockwise using the tuning key;
the thread is extremely fine so this will take a while, but the pin will come
out.
If the pin has an oblong head, try the same technique at first, but as you turn
the pin, exert an upwards pull while turning. This may work, in most cases it
does. If this doesn’t seem to work, try turning the pin to and fro as you pull
upwards, but on no account lean the pin out of its’ axis. Wrest-planks are wood
and the pin being steel will elongate the hole if you do this. The weapon of
last resort is the pair of mole grips, fastened in line with the axis of the
pin. Twisting gently to and fro while pulling upwards will always work. Set the
pin aside. Determine the thickness of replacement wire either from the list you
have or by asking advice of a maker or technician, or simply measure an adjacent
wire if you have access to a vernier or a micrometer.
Now uncoil the new wire carefully. Putting a kink in the new string is not an
option. If you do fit such a wire and the kink is in the sounding length of the
string, you will hear the funny sound all the time, while tuning and while
playing, until you succumb and put another string on. Hook the loop onto the
hitch-pin. Carefully uncoil the wire, pulling it gently as you get back to the
playing end (of a harpsichord...you know what I mean) and pick up the tuning
pin. Now you need to estimate how much string you need to coil around the pin
before popping the pin back into the hole. Try to make the coiling match the
rest; for a zither pin, each turn needs about 15mm of wire so if the other pins
seem to have ten coils you will need 150mm, so thread the wire end through the
hole in the pin and hold the pin about that 150mm beyond the hole, holding the
pin horizontally with the square end to the treble, to your right. Bend the wire
at right angles so that it lies along the pinto your left. Now roll the pin away
from you so that the wire coils onto the pin with the tuning pin rolling above
the wire, keeping some tension on the wire all the time. The coils should lie
neatly next to each other. Stop when you estimate you have two turns to go, and,
still keeping that wire taut, pull the over-length (which has become neatly
trapped under the coils) out, at right angles to the pin; wobble it to and fro
and it will break off neatly. Steel wires need cutting but all others will break
easily when this sort of work hardening is used. Now roll on those last two
turns until the pin reaches the hole, turn the pin to the vertical and position
it in the hole. Tension still needs to be kept on the wire, but once the pin has
entered the hole you can apply enough by pushing the wire sideways with a spare
finger. Reach for the hammer, (tuning or domestic), and tap the pin into the
hole nearly as far as the rest, and immediately use the tuning key to tighten
the string a little. Now settle the string into position around the bridge pins
and tighten the string to somewhere near pitch. Now check that the loop on the
hitch-pin is firmly down on the surface of the hitch-pin rail, or in the case of
4’ strings, onto the soundboard, pushing gently with a small object. I use a bit
of wood, usually a 3mm dowel, but a pencil will do, not a screwdriver because it
can slip and mark the wood and it can cause a mark on the surface of the loop
which will make the wire break, now or at a more inconvenient moment. Now you
can bring the string into tune, and tap the pin down to the correct height if
necessary. The last coils must end up a millimetre or two above the wrest plank
(this is true of all strings. Strings that try to bury themselves into the
wrestplank over time and tuning often break) and this can be adjusted by letting
those last few coils (after you break off the over-length) lie further down the
pin.
A new string will stretch for a day or two, and must be repeatedly re-tuned.
It’s a good idea to mark the pin to save hunting for the it, either by cutting a
little washer of cloth and popping it onto the pin, or use chalk on the top of
the pin. Iron wires will take a week to really stabilise, brasses considerably
longer; and the sound may be different to the adjacent strings for a lot longer
than that as the metal changes.
Oblong headed pins with a hole drilled for the wire are done exactly as above,
but the pin is usually smaller in diameter, and longer, than the zither pin.
Many more turns of wire are usually wound onto them, really just because it
looks nice. You can still work out the extra length you need (number of coils x
diameter of pin x 3.142) but there’s no need to be exact. the other reason for
the larger coils on these pins is to make them resemble the way old harpsichords
are strung., which brings us to the matter of fitting wire to pins with no
convenient hole drilled. In this case the wire is held in place by friction
alone and so many coils give better grip. Old tuning pins, hand made, are rough
and give good grip to a soft wire.
To fit a string, the pin is laid along the string with the oblong head facing
away from you at the point where you want to start the winding. Holding the wire
firmly against the flattened bit of the pin with the right hand, and the
over-length lower down the pin with the left, twist the pin to make a right angle
to the wire so that the pin is in the same position as with a drilled pin, and
start rolling the pin as before, trapping the spare length under the coils. It
is obviously necessary to keep tension on the wire and keep the wire coiling
over the over-length, and to be a contortionist at least for the first three or
four turns, after which giving a sharp tug to the wire will settle the coils and
‘fix’ the wire so that further coils can be added neatly and with ease. Ensure
that you keep tension on the wire or the coil may loosen, and proceed as before.
Photos needed:
1 different types of tuning pin
2 tools
3 removing tuning pin
4 different types of loop?
5 starting coils
6 rolling up
7 break off over-length
8 turn pin and fit
9 tap pin down
10 settle loop onto hitch pin rail
11 cup of tea