Restring Nut

[Richard Brekne]

Hi list.

Recent reading and posts on the list has given me the impetus to try something
out. I am normally rather conservative about attempting things I know are over
my head, but I just couldnt resist.

I have in the shop a Brother Hals Piano. Americans wont probably have heard of
this, but Scandinavians know them well and they are not particularily popular
amoung tech. It is a Danish make from around 1880, birdcage. Typical for the
design, long sustain, weak tone. From middle C there are just 2 strings
(unwound) down to  the E below where 3 wound double string unisions take over
before the bass bridge begins. The piano has ribs like every 2 inches or so.
Lots of them. They are triangle shaped. That is they angle up to a point on the
top. The soundboard is 8 mm thick, some small amount of crown (a straight edge
taken across the top of the board, angled with the tenor bridge with strings off
shows about 2 mm space at each end.) There are no cave-ins on the board
anywhere. The stringing scale makes no use of halve gauges. Unwounds start at
wire size 22 (2 unisions) then 21 for 2, then 20 for 2, then 19 for 2 and then
starts spreading out ending up at 14 until the last three unisions finnally make
use of a half gauge, 13.5. I wont get into the bass strings this time around.

The board rose almost not at all when I took off the strings. So I thought like
this. Lots of ribs... board has no cracks and has never been repaired... bridge
shows almost no indentation from strings after all these years... piano had long
sustain and weak tone above and beyond what overdampers can explain... little
but some crown..........

This thing (soundboard) must be really stiff, so I decided to lower the plate
and set string deflection at 0.5mm treble and 0.8 bass. (at low tension) And I
decided to split the difference between each treble string gauge section and
insert halve gauge sizes (18's over to 17.5's etc) to spread out the scale a
bit. Not haveing a scaleing program, and this being just a first try at such I
decided to just keep it real simple. I am pulling it up to pitch tommorrow so I
will know how it sounds.

What I am after with all this is to see if I have understood any of what I have
read recently.. grin. It seems like there should be to some degree a
predictability about the general sound quality based on the condition of the
soundboard and bridge. My reading was in this case that the board was too stiff
in relation to the scale, thereby all the long sustain and weak tones. The other
conditions noted seemed to support this. The change in scaleing was simply gut
feeling (I have almost no knowledge in regards to scaling)

So anyone out there in the know, I would appreciate your comments. This is the
first time I have conciously tired doing any thing else then duplicating the
previously existing conditions, being content to fix soundboard and bridge
cracks, and supplying the piano with new strings. So I would be very gratefull
for feedback and critic' on this first simple step.

Richard Brekne
I.C.P.T.G.  N.T.P.F.
Bergen, Norway