repair bridge

[Chunping Ding]

Dear Dave,

Thank you very much for your kind advice. I eventually removed the bridge and
its apron from the soundboard. I found some old bridge from  another piano, and
put it back to my piano. However, the volume of the sound is very small. I
guess the reasons for this may be:

1. I did not use glue between the bridge and the sourdboard. (Because I am no
so sure about the positions of the bridge and the pins etc. I would like to
play with the new bridge). However, I do not understand why do we need to put
glue between the bridge and the sound board? I think that the pressure from the
strings are strong enough to stick the bridge on the board.

2. The contact between the bridge and the sound board are not smooth. When I
take the bridge off the soundboard. The soundboard are slightly damaged. I hope
after I apply glue between the soundboard and the bridge, the sound will be
better.

3. Using the new bridge, the speaking lengths of the strings are smaller.

The heights of the new bridge is the same as the old one.

Hopefully, after I apply glue, the sound volume will be increased.

Any advice,

THank you again,

Chunping


DGPEAKE@AOL.COM wrote:

> In a message dated 5/21/99 6:02:07 AM Pacific Daylight Time, cding@att.com
> writes:
>
> << 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
>
>
> Chances are it was put on with animal hide glue.  Mix 1 part wallpaper
> remover to 1 part H2O and apply on the glue joints.  You may want to apply
> some heat from a heat gun to help soften the glue.  Make sure all of the
> screws are removed.  Sometimes part of the soundboard may come with the
> bridge, but that is not a hard repair, if you do not remove the part off of
> the bridge.  Another alternative is to apply epoxy in the cracks rather than
> recap. Email me privately and I will tell you how to do it.
>
> Dave Peake, RPT
> Portland Chapter
> Oregon City, OR