repair bridge

[Jim Coleman, Sr.]

Hi Chunping:

Many pianos have about 3 screws which are applied from underneath the apron.
It would be necessary to remove the entire bridge assembly to get to these
screws. There are usually screws going from the back side of the soundboard
through soundboard buttons into the apron. These must first be removed. The
vinegar should work if the piano is an old upright piano which used animal
glue. The modern glues would probably not work with vinegar or even acetic
acid. Heat and a sharp chisel might help. Sometimes, just a large hammer
works.

Jim Coleman, Sr.

On Fri, 21 May 1999, Chunping Ding wrote:

> Hi, everybody.
> 
> I am new in piano technician team. My first major task is to repair a
> seriously cracked base bridge of my upright piano. One fourth of the
> pins are loose. I would like to re-cap the bridge. Firstly, I would like
> to take the bridge off the sound board. I tried to put vinegar between
> the bridge and the bridge apron (shelf). However, I failed to dissolve
> the glue. Does anyone know any more powerful dissolvent? Or do I have to
> use some special vinegar (I used my cooking vinegar)? Or is there any
> hidden screw between the bridge and the apron? Then I tried to dissolve
> the glue between the apron and the sound board. I failed again. Could
> someone give me some hints on how to take the bridge off?
> 
> Your help is highly appreciated.
> 
> Chunping
> 
> 
>