Rebuilding for Performance or Show? changes - Isaac OLEG's list

[John Hartman]

Isaac OLEG wrote:
> Hello, thanks for answering so fast ! I believe I understand why you
> like less dense felts for the pianos you work on - if I understand a
> tad what kind of tone the American made pianos are for.
> 
> What I don't really understand is if this is due to the kind of
> soundboard build (very light and may be flexible) , the strings
> scaling, or a whole based on the kind of tone you prefer.

I am not sure how hammer voicing is related to how the soundboard is 
built. It probably has to do with how the whole instrument is build and 
in what condition you find it. I have noticed that different types of 
grand pianos require different voicing techniques. Most of my experience 
is with American grands and I have a good idea how to voice them. When I 
work on european grands (not often) I find myself a at a bit of a loss. 
There is a difference in aesthetics as well as design that throws me off.

I can definitely tell when the soundboard of a Steinway grand, for 
example, is not doing all it should to radiate tone. This can get in the 
way of accomplishing a good voicing job.


> 
> I see that European instruments, are generally more oriented to a more
> dense tone , the French trade being a little different but still some
> density is present even on open tone pianos.
> Too light felt in the idea you give me will not really work well in
> all registers on the French pianos I have in mind (1930-1950) because
> the where yet aiming for some power with the iron framing, they don't
> like hardness, the molding is generally light and thin , but not as
> much as for forte pianos or such. Never seen as soft a felt as in US
> Steinways for instance.
> 
> More often multy layered hammers where used to try to have a dense
> foundation in the middle of the hammer, while the external layers
> where softer.
> 
> "German felt" is not saying so much to me, I made a search on the
> Germany phone book and more than twenty felt makers are yet present in
> Germany, as You may have read on my last post I know yet 2
> possibilities for sure, between VFG and Wurzen, but I've been told
> others produce felt for pianos. We are trying to find more precise
> information with my friend Stephen Paulello (which is preparing the
> building of a series of 2.17 M grand's)
> 
> It could be a tad of a problem if some hammers in a set where so bad I
> should use 2 sets for one piano (I've done it yet with Runners, but
> for sure don't like the idea much).
> Hand made does not mean every individual hammer is pressed separately
> I guess (is not the Dodge machine allowing for a full set at once ?)
> 
> But I understand inconsistency may shows up in the process of
> tensioning and gluing, of course when the felt is in the cauls there
> is little control on what happens. Our French re-felter use a modern
> Renner machine to put the felt in shape, possibly with some warmness,
> before gluing it cold with its old almost wooden hammer press (with
> the large screws they have to turn everywhere to press the cauls.
> They have sometime very nice results but it is not often enough in my
> opinion, and most technicians here seem to live with that and not
> asking more unfortunately. SO we see many sets that are lacquered
> immediately, and in my opinion the tone is very limited when doing so
> (even if it can be fairly acceptable for sometime) Particularly with
> the Laoureux felt, once lacquered, tension is almost inexistent if it
> have been compressed a bit to begin with.
> 
> I have no experience in shaping a whole set (before wiring it I guess)
> and I am afraid I should do insufficient work on those matters. Is it
> a very difficult task to learn (I've seen it done, but still ...)
> 
> Thanks anyway for the information about that light felt specialty,
> I'll keep that in mind. I guess I will begin using a vertical set for
> a Pleyel N?3 that I own, Ill get a feel for these hammers in the
> process I hope.
> I can drill so that is enough a good thing for a beginning !
> 
> For sure these hammer's questions are one of the most concerns (even
> if I begin to be better at ease with actually)
> 
> For scaling and belly work I have plenty of good help (a little too
> much sometime), while basically I am more a technician, finisher,
> tuner, I try to obtain some skills in basic intelligent rebuilding
> (more real than the ones I learned twenty years ago). That is the
> reason of so much questions I ask. Being not an expert in woodworking,
> I have many roads to cross, but things evolve, with time (and I have a
> real shop with some real tools also !!!).
> 
> My Very Best Regards to you.
> 
> Isaac OLEG

Thanks for you insights into hammer making and how it influences you 
work. Maybe I did not make myself clear about what I am looking for in 
hammers for rebuilding. So simply put:

1) I want hammers that are reasonably light in weight. I fit each hammer 
set to work with each action in terms of weight. So it doesn't need to a 
specific weigh but medium to medium light.

2) I want the felt to be soft, not too dense. This usually goes a long 
with a light weight hammer.

My voicing technique:

1) Get the weight of the hammer down. This will give a bright tone with 
soft felt. This is one reason why they got away with such soft felt back 
then (actually put these hammer on a scale and see how light many of 
them were).

2) Use hardeners when necessary to increase the dynamic range. Putting 
thin hardeners deep into the hammer increases the difference between the 
density of the crown and the core.

As you see it is the weight of the hammers and the density (from crown 
to core) of felt that matters to me. So far I am not much of a believer 
in finding the right felt and I don't worry much about how it is 
pressed.  Resilience if a term that is often misused when talking about 
hammers. What it more resilient, hammer felt or a hardened piece of 
lacquer?

John Hartman RPT

John Hartman Pianos
[link redacted at request of site owner - Jul 25, 2015]
Rebuilding Steinway and Mason & Hamlin
Grand Pianos Since 1979

Piano Technicians Journal
Journal Illustrator/Contributing Editor
[link redacted at request of site owner - Jul 25, 2015]