Bechstein Pinblock

Joel Rappaport joelr@flash.net
Tue, 29 Jul 1997 20:09:14 -0500


Stephen,
I hope the following will put your mind at ease.  I'll make a few
assumptions and hope they are accurate.  Your Bechstein was built around
1902 and you mentioned that the tuning pins feel good and only a couple
of strings have been replaced.  My big assumption is that the tuning
pins are the original size.  If they are, you will be happy to know that
Bechstein's original pin size is 6.75mm in diameter and 55mm long, which
is quite a bit smaller than what we here in the USA consider factory-new
tuning pin size.  Our "original equipment" #2 (or 00 or two-ought) pins
measure around 7.15mm.  Possible replacement sizes, listed in both the
Jahn and Renner catalogs, are 6.90, 7.00 and 7.10mm all of which are
still smaller than what _could_ still be considered factory-new size
(just a different factory!).  In addition, all those sizes are available
in lengths 55, 57, 60 and 64mm.  You would have to double check the pins
in your particular piano to confirm the existing size, both diameter and
length.

Another thing, I think the old pinblocks may not have been drilled all
the way through.  The "old timers" I worked with at the Bechstein
factory in Berlin mentioned that it should not hurt anything to drill
completely through the block when carefully drilling (we use a normal
drill bit, not a spoon-bitted reamer) each hole for the new pin.  I
would consider drilling with 6.8 and pinning with 6.90 or 7.00 (your
choice of length), having both sizes on hand and going completely by
tuning pin feel on several tests.

Original Bechstein procedure calls for dipping each tuning pin threaded
area in powdered rosin before installation.  My information comes from
being the factory stringer about 20 years ago, but should still cover
your vintage of piano.  I couldn't say for sure about the modern
procedures at the Bechstein factory.  Guess I'll have to make a business
trip to Germany to find out, eh?

Bonus, un-asked-for advice:  if you are going to replace the hammers,
don't forget that, if the agraffes go all the way up to the top, the
hammers are drilled not at 90 degrees, but 91 degrees (tilted away from
the plate-pinblock-agraffes) so that the top treble hammers do not hit
the plate into which the agraffes are installed up there where space is
close.

I hope this will help you to avoid unneeded major work, will keep your
estimate cost down and that you get the job.

Best regards,

Joel Rappaport
Round Rock, Texas

Stephen Powell wrote [edited]:
> 
> I came across a 6'6" Bechstein of this vintage (#63955) in a
> local hall a few weeks back......The
> piano is in very good condition really; there are no plate cracks, and the
> soundboard seems excellent with good down-bearing.  One bass sting and one
> high treble string has been replaced.  The tuning pin tightness is adequate
> to keep the piano in tune and (I think) even throughout the block.  IMO the
> piano is due to be restrung with new hammers etc.
> 
> Should I resting with oversize pins or install
> a `floating' block?  Or, should I prepare myself to the max and follow
> Bob's procedure?  My dilemma is that if I report to the council that I'm
> not equipped to do this work, another tech will come in and resting with
> oversize pins anyway! (I think the chances of this happening are quite
> high). And I don't want to risk losing my council work.
>




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