[pianotech] Center Pin Zapper

[Poppy Miles]

Although I'm still entertaining the idea of making a zapper ( I saw one that seemed to work without burning the birdseye or the bushing cloth). This zapper is pretty elaborate, and manages to deliver a very small charge through the pin, and has a beeper that goes off when you locate the sides of the pin with sharpened tongs made of spring steel ( the charge is deadened with a block of wood where you grab it.) The main thing that has discouraged me from making a copy of the one I had used, is I don't like the idea of heating up the birdseye. I've heard they can be worse than a waste of time. I would  have to make, and study the effects of this tool on a scrap part before feeling confident it would be safe and reliable. A few of you said they are not. Without a sort of experiment where the humidity is controlled or measured alongside a reamed part, I can't be sure. Reaming works well, but all pinning changes with humidity. Also, after reaming
 the bushing cloth is fuzzed up, so the action center needs to be worked in order to smooth it. You also have to be very careful to ream evenly, and there is a chance of pushing out a bushing. Sometimes, after repinning the part becomes looser, because the part wasn't worked enough. I've seen alcohol/ water treated bushings regain a little of their tightness, but I'm not sure if that was due to a change in the humidity or not. It's also easier to get a small change with reaming, than with a solution. You also have to wait for it to dry. I've saw a demonstration at convention where the lecturer used the old trick of heating up the centerpin with a lighter to loosen it. I tried this and wished I hadn't, ( the bushing looked a little charred). I'm sure there are people who this technique works well for, but I will pass. I do actually reason for giving you all this well known info: all methods seem to have drawbacks. So why not try a new one? My key
 bushing iron works well, so maybe using heat instead of electricity, reaming, or solutions could work. Maybe there's not enough pressure on the bushing with a zapper, and the problem of heating the birdseye could be eliminated ( by separating the parts.) If anyone feels like designing a heated centerpin caul type tool ( modified soldering iron attachment), a variation on the lighter method where the amt of heat would be controlled more carefully, I think it might work. That said, I will continue using my reamers, after all, I am patient as is anyone who has read this incredibly long post.



----- Original Message ----
From: David Ilvedson <ilvey at sbcglobal.net>
To: pianotech at ptg.org
Sent: Wed, March 3, 2010 5:49:44 PM
Subject: Re: [pianotech] Center Pin Zapper

Yes...zapper is a waste of time

David Ilvedson, RPT
Pacifica, CA  94044

----- Original message ----------------------------------------
From: "Gregor _" <karlkaputt at hotmail.com>
To: pianotech at ptg.org
Received: 3/3/2010 1:26:13 AM
Subject: Re: [pianotech] Center Pin Zapper



>I never heard of that idea of a zapper and it sounds really weired to me. How long 
>does it take, I mean how long do you zapp one center pin? Would it not be easier, 
>quicker and more long lasting to replace that pin?

>Gregor

>------------------------------------------
>piano technician - tuner - dealer
>Münster, Germany
>www.weldert.de




>> Date: Tue, 2 Mar 2010 15:09:57 -0700
>> From: mark.purney at mesapiano.com
>> To: pianotech at ptg.org
>> Subject: Re: [pianotech] Center Pin Zapper
>> 
>> I've heard other claims that the results can sometimes be permanent, or 
>> at least long-term. Maybe the ironing effect of the heat reconfigures 
>> the bushing fibers in some cases, but not others?  I'll experiment and 
>> see what kind of results I get - it's not a complicated or expensive 
>> device to build. Thanks for the information!
>> 
>> 
>> On 3/2/2010 1:57 PM, Michael Magness wrote:
>> >  I have one I rarely use, it's results are temporary at best. The 
>> > results of the device is/are heat, resulting in drying the flange 
>> > bushing cloth thereby cauing it to stop sticking. The problem of 
>> > course is that the humidity returns and with it the problem.
>> 
>                         
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