In bleaching ivories I have, before retirement, used the following
method:

- Fine sandpaper the upper surface for uniformity.

- Bleach with 130 vol. hydrogen peroxide.  Use with care as it corrodes
skin.  Use a cotton tip.

- Expose to sunlight or an ultraviolet lamp.  Repeat peroxide bleach
and exposure as necessary.

- Polish-buff with white buff and white compound.


In attaching old ivories to the keys I did this:

- Scrape the key top and ivory under-surface clean and flat.  Ensure
that the tail-to-front joint is perfect.

- If the ivory is curved, soak it in a saucer of hot water.  It can then
be straightened easily.

- Prepare a piece of good quality white typing paper to the correct size.

- Coat the key, paper and ivory with a smooth layer of aliphatic resin
(Elmer's glue) or Weld-bond white glue, not PVA which sets soft and
pliable and weakens with force and heat.

- Press all together and clamp using a metre of string, wound tightly
especially close to the front.

- First lay a loop of string and when all tightly wound, put the string
end through the loop and pull under the windings.  This is similar to
the windings on fishing rod line guides and locks all in place.

- Leave 24 hours to set before trimming to a finish.

Ronald Sharp