capo-hardening vs hardened capo rod

[Richard Brekne]

Richard West wrote:

> Some things in this long thread don't seem to add up.  So I have a few
> questions:
>
> 1.  Why is harder, better?  1/2 of most pianos are strung using agraffes, ie,
> brass.  Brass is not a hard metal.  As technicians we may not like to clean
> capo bars on ocassion, but if a balance between soft and hard is what makes for
> the best tone, then we may have to live with a softer capo.  We should be
> happy; it's job security.

I dont think it has ever been shown that harder is better. There are certainly lots
of people who think so, and the opposite is true as well. And  you make a good
point bringing up the hardness degree of brass agraffees.


> 2.  If capo hardening only penetrates 1mm, it seems that such a small amount
> would be filed off when preparing a raw plate for stringing right in the
> factory.  Are we really dealing with a hardened capo even on a new piano?

I think the 1 mm figure referes to "skin" hardness that results from the casting
process for traditional sand cast plates. The actual hardning of the capo bar is
independent of this and is done at a later stage in the process. That being said,
it is certainly possible to file away the hardness of a hardened capo bar.

>
> 3.  Why is strike point so critical/unforgiving in the octave around C6?  It
> seems that if I have "zingers" in that area it's more often a strike point
> problem than a capo bar problem, assuming that the capo has been cleaned up.

This one is probably pretty complicated and gets into other issues then plate and
front termination point issues.  Generally the cleaner and more precise the
termination point is the better the results. It may be that we end up being more
"picky" in our resolve to achieve this precision in this area but that the real
problems you point to lie in the soundboard assembly and scaling.

> 4.  In the battle for artist approval, why have "soft" capo bar pianos seemed
> to be the instrument of choice?  I know this is a loaded question.  After all,
> opinions are all over the map and what does the pianist know anyway?

I have not heard that they are... per say...  could you give some examples of what
you mean here ?
--
Richard Brekne
RPT, N.P.T.F.
Bergen, Norway
mailto:rbrekne@broadpark.no