[pianotech] Center Pin Zapper

[David Ilvedson]

Been there and done that...we got better things to fiddle with that really work.   Do you folks realize you are trying to help out a client who should be paying to have the work done right.   You are doing potential damage to their pianos parts.   Why make their problem your problem.   Fix it right or move on...

David Ilvedson, RPT
Pacifica, CA  94044

----- Original message ----------------------------------------
From: "David Boyce" <David at piano.plus.com>
To: pianotech at ptg.org
Received: 3/4/2010 2:50:04 PM
Subject: Re: [pianotech] Center Pin Zapper


>It seems to me that a zapper made from two soldering irons, and one made 
>by electric current, are two different types and may have different effects.

>In both cases, the intention is to heat the center pin.  In the case of 
>the soldering irons, the heat is generated in the center pin by 
>conduction from the very hot tips of the soldering irons.  In the case 
>of the electric method, the heat in the pin is produced by letting a 
>large electric current flow through the pin, causing it to heat.

>Now, with the soldering irons, the heat will spread from the ends of the 
>pin towards the middle, This means that the bushings will be heated 
>before the birdseye.  With the electric current method, might not the 
>pin heat from the middle of the pin towards the ends? In that case, the 
>birdseye will feel the heat before the bushings.

>It's my understandting also that DC is much more dangerous than AC.  And 
>that it's amperage rather than voltage that tends to be deadly.

>The whole business of heating center pins by passing electric current 
>through them seems fiddly and frought with problems, to me!

>David Boyce