Notes: 1) This is a handout from
a class on ivory bleaching which was presented over
five years ago, so the model numbers on the black light my no longer apply.
2) All chemicals were purchased from a local scientific supplier.
3) This page is posted temporarily as a courtesy to "Pianotech List," and is intended
not to be easily accessible to the general public from other areas of this web site.
"IVORY BLEACHING PROCEDURE"
1) Clean ivory keytops using a soft cloth, slightly moistened
with water and a little liquid hand soap.
2) Lightly sand the keytops with 320 grit sandpaper.
3) Insert two (4 foot long) Sylvania 350, 40 watt Black lights
(Serial # F40/350BL) into a fluorescent shop light fixture.
4) Prop up the light fixture on two small sections of wood.
(2 X 4's are recommended.)
The light fixture should rest on the 4 inch dimension.
(Use your browser's BACK button to return to this page from the photos.)
Photo 1 Photo 2
5) Prepare a solution of 35% of Hydrogen Peroxide (H2O2),
in a pump spray bottle.
(Note: A weaker mixture of H202 can be used for a slower process.)
6) Put on safety goggles and a respirator mask.
7) Spray a fine mist of the Hydrogen Peroxide mixture over the
keytops. Turn on the Black lights and place the keys underneath
the light fixture. WARNING! Although this type of ultraviolet
light source is supposed to be relatively safe, avoid looking
directly at it. Ultraviolet light has been shown to cause
8) Keep checking the keytops over the next few hours. As
Hydrogen Peroxide dries, you will need to re-wet the surface of
the ivory from time to time. Continue for at least 24 hours...
at your leisure... i.e.: There's no need to stay up all night in
order to "dose" the ivory.
9) Generally, satisfactory results are achieved in about 48 - 72
hours. The bleaching that actually takes place is more a
function of the amount of Hydrogen Peroxide applied than of the
length of time the ivory spends under the light. It will do no
harm to leave the keys under the light for long periods of time.
In fact, the light should be left on at all times during the
bleaching procedure. Leave the light on over night.
10) IT IS POSSIBLE TO DAMAGE THE IVORY
BY OVER BLEACHING!
DO NOT USE TOO MUCH HYDROGEN PEROXIDE!
a) If the grain in the ivory begins to look extremely
b) If the ivory begins to look like a "bleached out" Sand Dollar
on the beach...
c) If the ivory is already thin and begins to crack or lift...
d) If the Hydrogen Peroxide on top of the key starts to look
"foamy" or "bubbly"...
e) If in doubt... STOP!!!
Remember that You can always
but you can't undo what you've already done.
11) When you're satisfied with the bleaching that has taken place,
turn off the light, remove the keys, and clean the residue off
of the ivory with a damp cloth.
12) Sand the tops of each key with 400 grit sandpaper in order to
smooth out any rippling or pitting caused by the bleaching
13) Buff keytops. You're finished.
A FEW MORE WORDS OF WARNING
As stated above, the ultraviolet light source used in this procedure
has the potential of damaging your eyesight. It would be wise to
wear sunglasses with verified U/V protection, or to build your light
source with U/V protective film available from "Edmund Scientific".
Hydrogen Peroxide, in concentrations of this magnitude
can be extremely dangerous... EVEN EXPLOSIVE. Follow all
warning labels closely. Use with adequate: Eye, Respiratory, and
If in doubt, tell your supplier what you intend doing
with it and ask them for their advice on safe handling.
U/V PROTECTIVE FILM: Edmund Scientific
101 E. Gloucester Pike
Barrington, NJ 08007 (USA)
Ph # 1-(856) 573-6240