Regluing Ivory

[John Delacour]

At 8:02 am -0400 22/4/02, Jon Page wrote:

| I have a keyboard looming in my near future where +25% of the ivory is off.

Yes, I've got three keyboards on the go at the moment, all of which have 20
or so central ivory heads loose or badly reglued.

| Before I start fashioning jigs, has anyone devised a means to keep the ivory
| in place while the hot glue sets under the heated ivory plate.

| Once the heated plate is clamped, the ivory has a tendency to slide on the
| water layer underneath. Some means is needed to secure the ivory on the key
| and not interfere with the plate.

I use two fixed clamps or rather clips, one at each end of the head.
_____________________    These are made of 3/8" plywood and cut to
|                   |    fit tightly to the sides of the key.  Since
|                   |    there is variation in the width of the keys,
|     _________     |    pairs of clips are prepared with slightly
|    |         |    |    different gaps and the inner sides can be very
|    |         |    |    slightly tapered.  Once the brass plate has been
|    |         |    |    lightly clamped down, the clips are pressed on
|    |         |    |    fore and aft and the clamp is then fully tightened.
|____|         |____|



| I have tried all types of other adhesives and am convinced that hot hide glue
| mixed 5 to 1 with titanium oxide (show white) is the best, longest-lasting
| method not to mention authentic.

I do the same.  Once I have ironed off the loose or ill-fitting heads, I
clean up the key-tops, removing any chemical glues etc. with paint stripper
or solvent.  I then paint the tops with a thinnish size of glue and
titanium, sometimes lightly sanding and applying further coats intil I get
a perfectly smooth and white surface.  I use the mix also to build up spots
where the glue has pulled away.  The original or replacement heads are
washed in lukewarm water to remove all traces of glue, and I then bleach
them partially as necessary before letting them dry thoroughly and then
gluing and clamping them, this time with a thicker glue/titanium mixture.

| I  usually leave the ivory clamped for at least three hours when
| simply securing loose fronts.  Would a longer time period be more
| beneficial for a full length ivory glue set?

I'd say that was quite long enough.  I prefer to remove the clamped plate
much sooner and replace it with a spring clamp and a wooden lath, or you
can just use ribbon or masking tape to hold things while the glue sets
really hard in a day or so.  To firm or too long clamping can crush the
ivory and the wood.

If the head is loose only at the front and the glue is clean, which is
quite common, it is often adequate to clamp the key at the joint in a small
vice, raise the front and slide in some glue.  A colleague of mine uses a
clear epoxy in this case and I have been successful with this method for
the odd key.

I find it useful to bleach the keys partially before I do any repair work.
The swelling of the ivory will show up all the keys that need regluing and
cause them to come loose.  The firmly glued keys will be unaffected.  This
way you avoid the guesswork and the wishful thinking and will have no
trouble with the keys one they've gone home.

JD