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Hello Barbara,
Some comments interposed.
Barbara Richmond wrote:
> Robin,
>
> Do you think if I did some tests on pieces of bushing cloth, I'd be
> able to tell anything?
To test the method with methyl alcohol you could try it with an
old flange and bushing if you have one lying around, which you probably
do. This will probably show whether the two will work together or
not. Tomorrow, I'll try it here in my shop and report back to. I very
much doubt there could be any problem using the three ingredients
together but I am no chemist either. I do know, though, one should
avoid breathing fumes from any of the three where possible.
Using it on bushing cloth could only show whether the mixture was
compatible with the alcohol. I don't see how it would indicate much
otherwise so why not use a real bushing which is in place and much more
true to the situation one is trying to test.
I was thinking in particular about the 90/10 acetone/ CA mix and also
trying out some with a bit of methyl alcohol mixed in, too. Does
anybody know if I'll blow up or pass out or anything? (That last one is
the important one, I'm not a chemist.)
>
> I repinned some again yesterday, following very precise directions by
> folks who should know.
I use similar methods in pining and did with the Tokiwa flanges;
they were inadequate due to the excessive softness of the bushing cloth
which had been used to bush the set. I had little expectation these
suggestions would help here. They are predicated on acceptably
densified, or adequately hard bushing. Possibly by taking the pin
size up to 25 you could get come stability for a longer while, but
this, again, is probably only going to be short lived.
> I was more aggressive in my burnishing and working the flanges and
> just generally pinning tighter, but by this morning, they had loosened
> some (I measured each step using my gram gauge). The flanges went
> from too tight before working the flange, to the high end of being
> acceptable after working the flange. This morning they were at the low
> end of acceptable--which is OK as long as they stay there, but I
> have a funny feeling they won't stay there for long.
They are very unlikely to stay there long at all. Again, the
problem that I see, judging from your description is likely do to an
overly soft bushing cloth have been used. They may well, actually,
have been sized at the factory but this effort has not densified the
bushing sufficiently, which was probably too soft to begin with. The
use of water again, may render them acceptable, although I doubt this
will occur.
In my opinion, it is necessary to do something due to the overly
soft cloth, which is similar to what one does when rebushing keys, that
is, through a similar process to the glue-sizing done when replacing
key bushings which allows the glue in that case to wick into the felt
and size them to a certain dimension. While we are not actually trying
to size the bushing, I think to a certain dimension, we are trying to
increase its functionaly density which impregnating the felt matrix with
a very thin deposit of plastic does, I believe.
> After this test of my pinning technique, I have come to the
> conclusion that perhaps I'm not totally incompetent after all----maybe
> just partially.... :-)
>
I don't think your technique is at all in question, rather, it is
just another case of technical inadequacy on the part of the supplier,
of which there continue to be an abundance of instances. In my opinion,
when buying parts from any supplier, who represent themselves as having
a professional level of competence, much less the elevated, somewhat
pretentious claims of this particular one, technicians should at the
very least receive a professionally adequate product. Sadly, with this
company, and numerous others this is frequently not the case. And this,
notwithstanding the tremendous, dominating understanding and
superiority in all matters technical it once readily displayed.
Regards, Robin Hufford
> Barbara Richmond
>
>
> ----- Original Message -----
>
> From: Robin Hufford <mailto:hufford1@airmail.net>
> To: Pianotech <mailto:pianotech@ptg.org>
> Sent: Monday, December 06, 2004 1:31 AM
> Subject: Re: Rebushing centers
>
> Hello Barbara,
> I think it is vital to properly shrink and stabilize the
> bushings after installation. Otherwise, you will be where you are
> now with the inadequate Steinway parts (something ridiculous and
> telling in itself for a company in business doing this for 150
> years,) you refer to in recent posts, that is, the friction will
> not be stable and the hammer will also wobble causing a loss of
> power.
> I have used shrinking fluid combinations with proportions
> ranging from 50/50 to 75/25 or so, water and methyl alcohol and
> had good results. Although, I have had, on occasion, a need to do
> some over, as some were still, after drying, loose. These were
> then rendered acceptable after another treatment.
> An interesting new possibility, which had occurred to me one
> day as I was waiting for a conventionally treated set to dry and
> is, as far as I can tell, a completely new technique since I have
> not seen it referred to anywhere or heard any discussion about it
> elsewhere, I decided to try on a set of Tokiwa shanks which had
> a very soft, unstable bushing that responded to pining exactly as
> you describe with the Steinway, is, perhaps, better.
> This method uses water thin CA glue thinned even further to
> about about a 90/10 acetone/glue mix. It occurs to me now, as I
> write this, that it may work better if a little methyl alcohol is
> added as a wetting agent, if possible, although I haven't done
> this. There may be complications if alcohol is used which I am
> unaware of at the moment.
> As you know, of course, the CA rapidly sets and this
> characteristic obviates the need for the prolonged drying
> necessary when using water. One can vary the mixture as desired
> to control its effects, but if too much CA is used it will make
> the bushing so hard that it will click and this defeats the
> purpose of its use. Too little and there is not enough stability
> induced in the bushing.
> On the piano I tried this on I have had very good results;
> the pining is stable and there was a noticeable increase in
> power. I tried at first to apply it simply by dripping the
> mixture onto the bushing: this does have an effect, but,
> eventually, I removed the pining, wetted the bushing and then
> reinstalled a pin. Perhaps, as I indicated above, a wetting
> agent like methyl alcohol will make it possible to do this without
> even removing the pining. All of the flanges on this piano had
> already been repinned, some twice or even three times. They had
> progressively loosened as you described earlier.
> Judging from your recent posts you are considering
> rebushing the inadequate Steinway shanks you have referred to. I
> would try this technique before rebushing were this problem one I
> had to solve. I think, once resigned to rebushing, you have
> nothing to lose.
> Regards, Robin Hufford
>
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