larger bridge pins (drilling)

[Isaac OLEG]

Ron, thanks for transferring,

yes that came in another folder, I am so glad to receive personal mail
that I like the feature, but I forget to use the "answer to all"
switch too often (and your post does not appear in the list I receive,
while I know it is there).

The board have really too little crown to be interesting (still in the
3 mm figures in the middle, but rolled almost flat in the K. zone) ,
but I've seen yet old boards that I've used little DB on, firm bridge
pin, notching, nice hammers, strong regulation (that is of utmost
importance as regulation makes clear to the intoner the capacities of
the instrument ), and, under home situation, the tone was so much more
powerful and sustaining that the old board was not a problem.

Of course the customer knew the piano before, that helps.

I am not advertising actually that I will bring the piano back as if
it where new, so things are under control.

I'd tend to think that we can gain a little sustain with good
terminations, and precise bearing, but the kind of gain we obtain with
a temporary fix, as DB on a yet flat board, lend to an unpleasing
tone, and probably not lasting long repair.

Yes, next step is .... buy a Clavinova

BTW what rule of thumb applies for the drilling (reaming in my case)
of the bridge pins , I'd consider 1/10 mm (a bit more than 1/32) drill
less to be a maximum for these pins ? I have all sizes drill by
tenths.

Considering the use of C.A., the product is known to not really resist
to shocks, then it may turn into powder may be, or is it only that it
break while remaining it's shape (loose bond) ?

Anyway it is strong enough on wood that when turning (I don't know the
term to make rounded wood parts) wood, it split, the operator use a
tad of CA that allows him to pursue the work. (I was told)

> I'd flatten the bridge top to get the middle the same
> height as the bottom  of the grooves at the edges. Those grooves
represent
> crushed wood, and a  string rest path rounded down at the edges.
You'll get a
> better termination  flattening the top.>

That make sense, and it is easier to check the DB  without them. I
noticed too that if we massage the string too strongly in front of the
pins, the tone deaden some sometime (so a very little tap is all it
need).

> >Admittedly I could shape the bridge to correct a (very
> little) rolling motion, but I am in trouble with the DB after that.
>
> You have to decide that yourself. Is there enough crown in
> the board so you  can position the plate height to get adequate
bearing
> without pushing the  board flat, or beyond?

I can have minimal bearing (but some) without forcing the board flat.
Beside, I see no real difference between flat and almost flat (from
the tone point of view) advantage is that the tuning is not affected
by humidity swings ;>)
Could it be that there is a point (flat board) where the board is more
prone to collapse, even under a minimal bearing ?

I guess I will try a metal belly brace on this one, that cannot be
bad.

> >Do you believe that adding DB in the middle of the board
> stiffens the killer octave, or is the opposite a better way (less DB
in
> the middle to expect a bit more life in the killer zone ) All that
under less
> >than good conditions unfortunately (very small curve)?
>
> Maybe temporarily, but isn't a fix, and will shortly be a
> problem again if  it's a problem now. None of the tricks you have
heard about
> fixing killer octaves caused by a too low impedance board will work
> except replacing the soundboard.

> Bearing should be set with crown and the stiffness of the
> board in mind. If  the board is dead, it's dead.

The board is responsive , but in the ZZZZZone , may be some
amplification ?

> >I will have a soundboard press in January (with go bars).

> I recommend pneumatic. There have been a couple of list
> discussions of  pneumatic press use recently. Check the archives
first,
> before you start building.

It is an opportunity from a colleague of mine that will leave the
country, strong large press classical model, very useful for more than
bar gluing. It can be modified I guess to accommodate pneumatic setup.


Thanks again.

Best Regards.

Isaac O.