pianotech-digest V2000 #984

[Walter Gramza]

Good Day Sir:

I am fortunate enough to have a zapper formerly made by frandis Mehaffey
which consists of a 12 volt transformer and a set of probes which look like
a large pair of tweezers.  You would place these probes on each side of the
frozen screws and a low amount of heat would pass through the screw and
shrink the wood surrounding the screw slightly making the screw frre up so
that it can be turned without difficulty.  The longer you keep the probes
on the screw the hotter it becomes and also the looser it will become.  If
you wish any further information concerning this device please feel to
contact me via e-mail at Gramza@bluemoon.net.  
Best of luck,

Walter GramzaAt 09:13 PM 11/12/00 +0100, you wrote:
>Hello Dave,
>
>When I had the same thing happening I drilled three holes with a 1 mm drill
>next to the remainder of the regulating screw.
>Then I pushed the remainder out, for there was no wood enough to keep it in
>there.
>After that I drilled a hole from the size of a hammershank, filled it up
>with a shank, shaved it off  and drilled a new hole for the replacement
>regulating srew.
>It takes some time before you realise you can't get it out neatly you know.
>I hope you can use this info.
>
>Henk Cousijn, Holland
>
>----- Original Message -----
>From: Dave Nereson <dnereson@dimensional.com>
>To: <pianotech@ptg.org>
>Sent: Sunday, November 12, 2000 5:54 PM
>Subject: Re: pianotech-digest V2000 #984
>
>
>> Does anyone know how to loosen up "frozen" (seized-up) regulating
>screws --
>> in this case, let-off screws.  This is in a Baldwin studio, only 20 years
>> old or so.  I tried turning them carefully and the eyelets would break
>off.
>> So I had to take off the button, grab the other end of the screw with a
>> vise-grips and turn out the remainder of the screw.  But in some cases,
>that
>> would break off also, leaving only that portion of the screw that's in the
>> wood, and nothing left to grab.  So I tried heating them all with a torch,
>> thinking the expanding metal would also expand the hole in the wood, then
>> when they cooled, they might turn easier, but no dice.  They still break
>> off.  And they're not even rusty.  I hate to put any type of oil or liquid
>> lube, thinking that would expand the wood cells, making the let-off screws
>> even tighter.  How to get the remainder of the screw out of the wood?  (I
>> can do it by carving away enough wood to let me grab some screw with the
>> visegrips, but hate to butcher the rail).  Can ya buy a new let-off rail
>> from Baldwin (it's the common studio model that's in many many schools)?
>>
>