pin blocks

[Robert Goodale]

Leslie W Bartlett wrote:

> I'd like to hear some discussion of delignit pin blocks.  I've
> encountered on  on a Samick (sorry to bring that name up.....) at the
> church where I do a bit of music, that is causing me some concern.  It
> has s number of loose pins. I replaced a couple with larger pins about a
> year ago, and now, they're loose.

<snip>
Whether you like or dislike Samick, (let's not go there again this time),
Delignit blocks are not a Samick product.  They are made in Europe from
European Beach and widely used there.  Just wanted to clarify that first in
case there was any question.


> I tuned a Kawai today that I tuned about a month ago (pitch raise)  At
> that time it had about thirty very loose pins. Today, pitch was
> considerably sharp, and the pins were tight.  That's good for now, but
> what happens with a decade or so and some more dry weather???????????

<snip>
Best to my knowledge, (I could be mistaken), Kawai is not using Delignit
blocks.  I'm certain they are maple.


> I'm curious as to how more experienced technicians view pinblock
> materials.

I don't believe that Delignit is a bad material by any means.  I have used
it for rebuilds many times with outstanding results: tight and smooth
feeling pins with no jumping or squeaking whatsoever.  This has not always
been the case, however, and I think much of this can be attributed to poor
factory techniques.  Delignit is much more dense than maple, and far less
elastic.  For this reason the pin holes must be to an exact size with the
understanding that the dimension is not going to change much once the pin is
installed.  For this reason a particular sized bit must be used.  I believe
that one of the problems with new pianos that use these blocks is that the
control necessary when drilling the holes is often lost.  It is critical
that the holes be drilled slowly with a sharp and cool bit.  If this rule is
followed there doesn't seem to be any problem and the blocks come out
beautifully.  In the case of factory production, however, I think the
temptation to rush the process is all to frequent.  Thus the bit becomes to
hot, charring the hole.  The bit is not changed or sharpening frequently
enough, compounding the heating problem and producing a less accurate
dimension.  These and other common production related deviance can
dramatically degrade the results.  Unfortunately these practices give
Delignit a bad name.

Rob Goodale, RPT
Las Vegas, NV