bridge repair

[Robert Goodale]

It sounds like this piano really requires a complete recapping job, however for
a short term budgeted repair I would suggest looking into an epoxy repair.  It
won't be as good as a new cap but it will work..  If we are talking about the
top two sections of the piano, you can loosen the tuning pins just enough that
you can slip the strings off their hitch pins and fold them back.  Start at the
high treble end and tie them back with another piece of wire threaded through
the ends.  Since you will be removing two whole sections it might be advisable
to lower the tension on the whole piano to minimize the risk of cracking the
plate.

You will need to remove all of the pins in the damaged sections.  You may want
to make a pattern because it can be difficult to install new pins in the correct
place if they bridges are badly split and they have started migrating.  Once the
pins are removed I highly suggest West System epoxy for the repair.  This type
of epoxy is exceptionally thin and works it's way deep into cracks.  It also
cures exceptionally hard.  It will fill the original pin holes as well but they
will be clearly visible and you can easily redrill them.  Clean up the bridge
surfaces before proceeding to make them smooth with absolutely no globs of
epoxy.  You can also clean up the notches a little with a chisel which will
expose new wood and enhance the look of the bridges.  Be sure to re-dag the tops
before you proceed.  I recommend gray liquid teflon.  After applying several
coats burnish it with an old hammer and it will look great.  Be careful not to
get the gray teflon in the notches.  You will want to use new pins which are
extremely cheep and they will look far better.  It will be nearly impossible to
get the filed ends of the old pins in the right direction again which would look
terrible.

Use the long pins with the pointed ends, not the short rounded pins.  Take note
of where they change size.  Bridge pins are not like tuning pins where you can
insert an "oversized pin" to make a loose one tight.  The difference in size is
substantial and guaranteed to split the bridge either now or in the future.  You
will have to use some creativity in filling the tops of the pins.  If this were
a complete repining or recapping job with the plate removed then you could
carefully take a belt sander and file off the tops.  In this case with only two
sections and the plate still in the piano you will have to do it all using a
file.  Using a sander with epoxyed pins can also heat the epoxy just enough to
boil it out of the holes and make a mess.  Stuff some rags under the plate to
help mute the sound board and wear ear protection because filing bridge pins
will make a heck of a racket.  When finished you should have a decent looking
bridge that is ready to go.

You mentioned that there were "overall value of the piano considerations".  I
would suggest you re-evaluate this position.  Knabes are very fine pianos and in
most cases well worth rebuilding.

Rob Goodale, RPT
Las Vegas, NV


David Love wrote:

> List:
>
> Encountered a 1928 Knabe (5'8").  The bridge cap, which extends down through
> both capo sections, is cracked and delaminating with some bridge pin
> migration.  The rest of the bridge is solid, uncapped and in good condition.
>   The board is good.  The piano has been restrung within the past 20 years.
> The strings are in good condition.  When the piano was restrung they put in
> #4 pins.  So, if I remove all strings in order to remove the plate and recap
> the bridge, I will have to replace the block.  I am trying to determine if
> its feasible to recap the upper part of the bridge without removing the
> plate.  Is it possible, or reasonable?  The plate struts do not get in the
> way of the pinning or notching, but I am trying to figure out how to get
> around the planing problem.  Any thoughts.  Budget limitations and the
> overall value of the piano are considerations.  Any thoughts?