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Hello David I,
I haven't heard any squeaks to date, possibly because of the
dilution or, it may be the case that CA just doesn't squeak. I say this
because two or so years ago when the possiblity of using CA like this
first occured to me I put too thick a concentration on a test bushing
which I then found to be too hard and, if memory serves me, noisy with
a click, not a squeak. I then rebushed this particular flange, shrunk
it normally (that is, with water), repinned it and gave it no more
thought until the problem with the Tokiwa flanges came up. So, I had,
later, at the point I referred viz a viz the ridiculous Tokiwa
bushings, already some concept of what might be useful as regards the
concentration to be used.
Personally, I don't believe a problem will develop if it hasn't
shown up now as the treated flanges have been subjected to substantial
play and the piano has been exposed to real extremes of humidity and
temperature with no problems in this particular set of flanges.
The only mechanical problem I can see to have any real possiblity
of developing over time would be a general pulverization of the
impregnated plastic due to the repeated shocks incurred in playing.
Were this to occur it may have the effect only of decreasing the
friction and increasing, again, the wobble, or, as you say, possiblily
causing a sqeak. If so, retreatment could cure this problem for some
period. Another possiblity , is that the pulverized material may
actually once again increase friction in the flange to unacceptable
levels. This would probably be dependent upon the dimensions on a
molecular level of the particular polymer that constitutes the plastic
and the interstitial spaces in the felt. These things, in my opinion,
are extremely unlikely.
Finally, in terms of functionality another possiblity of difficulty
exists which, I think, would be dependent upon the proportions used and
type of felt employed, and is the less likely the more dilute the
mixture. This would be such a combination of material as to make the
bushing hard enough that under conditions which diminish the size of the
hole, or swell the bushing, (in my mind this is increased moisture
although this point is argued here), that is that act in such a way as
to cause the pressure in the bushing to increase a result could be had
in which the pining becoming too tight, as can happen with a teflon
bushing. The proof however, will have to be in the pudding, that is,
in the use of the technique and observations of its effects over time.
Regards, Robin Hufford
David Ilvedson wrote:
>Glue wicking into flange bushing cloth is a source of squeeks. The CA glue isn't causing this problem? Because it is so diluted?
>
>David I.
>
>
>
>----- Original message ---------------------------------------->
>From: Robin Hufford <hufford1@airmail.net>
>To: Pianotech <pianotech@ptg.org>
>Received: Sat, 11 Dec 2004 13:29:39 -0600
>Subject: Re: Rebushing centers/mystery center pinning
>
>
>
>>Hello Richard, Don and Barbara,
>>A few more comments interposed.
>> First, I did try today the use of alcohol as a wetting agent; it
>>was useless as it served only to accelerate the reaction and
>>immediately harden the mixture as Don Rose predicted it would. Also,
>>while applying it to a piece of bushing cloth as Barbara considered
>>doing it was obvious that there really was no need for a wetting agent
>>as it disappeared almost instantaneously upon being dripped onto the
>>cloth. There was no discernible puddling or lag time. Again, this was
>>a Don predicated. Two for two. It may be however, that the
>>penetrabilty of this mixture may be different in a bushed flange whether
>>the pressure in the bushing may have to be taken into account. The
>>obvious effect of this stuff was to stiffen and harden slightly the
>>cloth as I intended.
>>
>>
>
>
>
>>Richard Brekne wrote:
>>
>>
>
>
>
>>>Hi again Robin, a couple comments below
>>>
>>>Robin Hufford wrote:
>>>
>>>
>>>
>>>>Hello Richard,
>>>> ..... However, simply because the claim is made that the bushing
>>>>is hard doesn't mean, in my experience, they will be, perhaps yes,
>>>>perhaps no, perhaps sometimes and one probably will not know when
>>>>until perplexing difficulties arise. One can take the
>>>>hammershank and flange in hand and hold the flange tightly while
>>>>trying to wiggle the shank in a way so that the pin can be made to
>>>>move back and forth in the bushing and watch this motion. A soft
>>>>bushing will show more motion of the pin in the bushing and that is
>>>>a serious problem as it has a really detrimental effect on the sound.
>>>>
>>>>
>>>Herein lies at least one tentative test for Barbaras flanges and it
>>>would be nice to hear what she observes in this regard. Up to this
>>>point I've been taking for granted that the bushings in question were
>>>as previously described.
>>>
>>>
>>>
>>>
>>>>Sometimes, as I Barbara and I both have experienced, repining is only
>>>>a temporary improvement; in the face of such a frustrating experience
>>>>I tried the method I described. It appears, as I said, at least for
>>>>the moment to have both worked at the time of use in stabilizing the
>>>>friction and wobble and led to no discernible subsequent pining
>>>>problem. But, again, its purpose was to deal with an overly soft
>>>>bushing.
>>>>
>>>>
>>>I have to admit I've never tried the kind of solution you describe
>>>above, being hesitant to apply any chemicals at all to either hammers
>>>or bushings. Too many unsatisfactory experiences for my part.
>>>
>>>
>
>
>
>> In general, I thoroughly agree: A clean pin, of the right alloy,
>>with a proper woven felt cloth, properly densified, I think, can be
>>shown to have worked for generations reliably and can continue to be
>>expected to do so. Why fiddle around with anything else? A lesson, in
>>my opinion, these various companies should take to heart. But they
>>don't and they put out, generally for frivolous reasons, the kinds of
>>products of which we are taking note of here. But, in this case, here
>>was a problem in need of a solution, which, in the case of my use of the
>>technique, appears to have worked.
>>
>>
>
>
>
>>>What I have found works very well is to work a good deal of teflon
>>>powder into the bushing and burnish very agressively followed by a
>>>rather tight pinning. Generally if I do have a problem afterwareds it
>>>goes in the opposite direction and I need to loosen things up a bit.
>>>Perhaps I might give your suggestion a try tho on some spares I have.
>>>Never thought of using CA in this context before.
>>>
>>>
>>>
>>>
>>>>If I were Barbara in this situation I would find two or three really
>>>>weak sounding notes from the middle and low treble and change nothing
>>>>else but the density of their bushings with the mixture, or take the
>>>>time to use water with alcohol, and judge from the results. I think
>>>>is absurd even to have to do this lesser task by necessity but even
>>>>more so when it is necessary to take the time to rebush parts for
>>>>which one has already paid good money to have acceptable bushings
>>>>come along with the rest of the order. I'll have to climb down off
>>>>my soapbox here before I get myself really worked up!
>>>>Regards, Robin Hufford
>>>>
>>>>
>>>Agreed, should be an un-needed operation for high quality parts. But
>>>then, assuming these are the new NY Steinway parts... we (I at least)
>>>dont know really what these are like from the get go. That said... the
>>>whole concept of bushings with such low friction does not appeal to me
>>>in the first place.
>>>
>>>
>
>
>
>>It doesn't to me either: I am not sure it is even a valid technical
>>idea and it seems this idea may only be a stop-gap attempt to deal with
>>the problems of geometry, excessive mass and friction which one sees in
>>the present production.
>>
>>
>
>
>
>>>RicB
>>>_______________________________________________
>>>pianotech list info: https://www.moypiano.com/resources/#archives
>>>
>>>
>>>
>
>
>
>>_______________________________________________
>>pianotech list info: https://www.moypiano.com/resources/#archives
>>
>>
>
>_______________________________________________
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>
>
>
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