Rebushing centers/mystery center pinning

[Barbara Richmond]

Thanks, Robin for saving me some time.  I was too busy yesterday to get to 
it (it's that time of year) and this weekend isn't looking so good either 
(family obligations).  If all works out, I will have time on Monday, to get 
back to this project.

Barbara Richmond

----- Original Message ----- 
From: "Robin Hufford" <hufford1@airmail.net>
To: "Pianotech" <pianotech@ptg.org>
Sent: Saturday, December 11, 2004 1:29 PM
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
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