[pianotech] ivory keytop repair

[David Weiss]

Any chance you could send a photo of the polyethylene block you are using?

David Weiss

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Douglas Gregg
Sent: Thursday, August 23, 2012 10:53 PM
To: pianotech at ptg.org
Subject: [pianotech] ivory keytop repair

Wim,
I agree with Paul and also Joe. I have two additional helpful tips. I made a
sampler of colors using an old ivory tail piece. I ground 5 notches in it
and filled them with varying amounts of the white and yellow colored powder
mixes. 3:1, 2:1, 1:1, 1:2, 1:3. this gives you a palate to compare to your
ivory to color match. This is similar to what a dentist will do when
matching a tooth.

Second, I find the biggest problem is the acrylic mix will slump when
applied on the overhang of the key. I first tried folding tape at a 90
degree and making a dam under the overhang. That worked fair. I now have a
piece of 1/8 inch thick polyethylene that I got from Smallparts.com.It
resists the acrylic so it does not stick at all.  On the table saw, I cut
pieces the width of the key and 1/2 inch long in the other dimension. I also
slightly beveled one edge that goes between the ivory and the facing
nitrocellulose on the front edge of the key. This allows some acrylic to get
under the ivory for a little extra support. Mostly though, the real
advantage is it make a nice dam to apply the acrylic. With this. I have
replaced the entire overhang on a key in one shot. It makes the job so much
easier. I did 40 keys on one Steinway for an owner who would not give up the
ivories. I got a good color match and it is hard to tell.

I do the sanding with the foam filled fine side of the fingernail that is
included with the kit. . Then I use 2000 grit wet or dry and final finish
with White Diamond polish. This give a great shine to the ivories. Use the
white Diamond on all of the keys and the owner will love it. They look like
new.

Doug Gregg
Classic Piano Doc




Message: 7
Date: Wed, 22 Aug 2012 12:26:07 -0700 (PDT)
From: Paul McCloud <pmc033 at earthlink.net>
To: pianotech at ptg.org
Subject: Re: [pianotech] ivory keytop repair
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Hi, Wim
I've done some ivory repair with Acrylikey.  Works well, smelly fumes tho.
What do you need to know?
I have a few things I can say about the procedure.  I use a magnifier so I
can really see.  I use a razor blade to bevel all the edges.  I use the
supplied dropper to put the liquid in the cup and add the powder to it until
it gets thick, but not too thick.  The liquid flashes off quickly, so I
start it off a little wet, and as I dab it on the ivory it gets thicker.
You can also put some tape over the front to prevent it dripping down.  When
the plastic gets solidified, but before fully hard, use a razor blade to
trim it.  Much easier than sanding a bunch off.  If you have voids or
pockets, just mix some more and dab it on.  Let it sit while you do the next
one.  I don't try to mix too much at one time.  New batch for each key.
Tedious, but it works.  When the plastic is fully hard, use the nail files
to sand down and finish.  You can also buff the keys after, but be careful.
Good luck.
Paul McCLoud
San Diego