[pianotech] ivory replacements with wafers intact using metal key plates

[John Delacour]

At 07:28 -0600 17/11/08, John Formsma wrote:

>Sounds about right, Conrad. ÊHowever, it has been quite some time 
>for me that I've had to do this. :-)
>
>Seems like there might be another way to glue an ivory without the 
>wafer process. ÊI remember hearing it in a class years ago. 
>ÊCombining glue with titanium dioxide to "whiten" the glue so it 
>won't be dark under the ivory when it dries.

That is the way I do it.  I mix titanium white in the glue cup with a 
medium consistency of glue.  You need to add enough titanium white to 
make the glue really white and opaque.

To heat the bronze or brass plate I put it in a dish of nearly 
boiling water for a ten seconds or so.  This heats the plate more 
evenly and to a predictable temperature.

No glue must be allowed to get in the gap between the head and the 
tail.  It's not a bad idea to brush the glue on evenly and leave it 
for 15 or 20 minutes to gel.  That way is is possible to place the 
ivory accurately without the risk of glue getting smeared into the 
joint.  Once the hot plate is clamped down the glue will liquefy and 
ooze out at the sides.

The clamps are designed to press the plate towards the joint, but 
they don't stop the ivory slipping sideways if they're not perfectly 
square.  When I have the ivory properly positioned and the clamp 
ready to tighten down I use two small clamps or pony clamps across 
the side of the key to keep the ivory centred.

If the dry joint is not perfect, or if you are using an ivory front 
from another note, draw the back edge of the ivory along a fine 
whetstone at a very slight angle  <-_____\_____<-  until the edge is 
quite straight but very slightly beveled at the under side.  This 
will make the job easier of getting the joint perfect.

Wipe off, with a damp cloth, as much of the extruded glue as you can 
get at while it is soft to save unnecessary work when it has gone 
hard.

A glue wafer should only be used if the keys were originally glued 
using wafers, which is very rarely the case in Europe.

JD



-- 
______________________________________________________________________
   Delacour Pianos  *  Silo  *  Deverel Farm  *  Milborne St. Andrew
                      Dorset DT11 0HX  *  England
                        Phone:  +44 1202 731031
          Mobile: +44 7801 310 689   *   Fax: +44 870 705 3241 
______________________________________________________________________