Rebushing centers

[Robin Hufford]

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Hello Barbara,
     The piano is still in my shop and I observe no problems with the 
pining,  treated as described, that can be attributed to the CA use.  It 
was done about six or so months ago.   This was not a truly organized 
study of cause and effect, but, rather a quick decision to try to 
overcome a frustrating problem chronically recurring which was the 
persistent loosening of the pining.
     If you were to use a mixture so insufficiently thin as to cement 
the bushing together and to the wood  also, perhaps there would be some 
difficulty removing the bushing.  Personally, I doubt this as all one 
would have to do is use the debonder or acetone.  The great advantage, 
to me, of using this, if it has a lasting permanent effect  absent 
problems, which I think it does, is that one can apply the mixture, as I 
said in the post, either with the pin in place or removed and still, 
within a few minutes or so reinstall the shank on the rail, play it and 
hear an immediate difference, attributable mostly to lessened wobble.   
Months later, the swing test of pining is within an acceptable range on 
those treated. 
     I also tried, on a few, where the pin had been removed, the use of 
the accelerator and, also, the use of a water-based Teflon spray as an 
accelerator.   I can't speak to the differential results of this just 
yet.   I will be curious to hear of the results you obtain, should you 
try it. 
     Also, although I have in a number of postings here indicated my 
opinion of the essential uselessness of hammers needing artificial 
hardeners, a controversial enough opinion but one, nevertheless honestly 
expressed, I have, on a very few occasions used a similar mixture of 
thinned CA to harden the last couple of hammers  in the treble and a few 
elsewhere at times, by injecting the mixture directly under the crown 
just above the tip of the molding in the high treble and placing  it in 
a similar location but avoiding wetting the underfelt elsewhere.  One 
then acquires the characteristic hardened sound which can then by 
needling be blended in.   This, then, led me to try it with pining 
problems. 
Regards, Robin Hufford

Barbara Richmond wrote:

> Wow, Robin, this is something! 
>  
> How long ago did you do this?  If there was a need to remove the 
> bushings, would the CA make them any more difficult to remove?  (I 
> just have to ask.)
>  
> Thanks so much for sharing your experiment!  Yes, I think I'll give it 
> a try--as you said, I have nothing to lose. 
>  
> 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
>
>     Barbara Richmond wrote:
>
>>     Here's a question for you who rebuild action parts:
>>      
>>      
>>     I've rebushed flanges before, you know, one here or there, but
>>     have never done a whole set.
>>      
>>     Are there any secrets besides just plain old rebushing?  For
>>     example, do you shrink the bushings after you've put them in?
>>      
>>     Thanks,
>>      
>>     Barbara Richmond, RPT
>>      
>>      
>

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