Kawai flange material.

[John Musselwhite]

At 08:30 AM 20/02/96 -0700, Avery wrote:

>on the subject, can someone please tell me the name of the black plastic-like
>material that is being used in Kawai's for flanges, etc.?

The material you might be thinking of is called "delrin". Among other
things, it's used to make the bodies for some 10-speed bike derailleurs.

>   Could this be the same material that is sometime used in harpsichords for
>the plectrum?

I have seen it used for harpsichord jack assemblies as well as the plectrums
(plectra?).

Kawai plastic flanges are made from "ABS Styran" and are usually a tan
colour to simulate wood. I've heard more than a few customers recoil from
the idea of "plastic parts", but the ABS is of an extremely high quality and
does function correctly, and in some cases better than the equivalent wooden
ones.

You might be interested in this: The Kawai Service Manual I have (which is
undated but has an intro by G. Defebaugh and is probably about 15 years old)
has some specific instructions on the care of those flanges. In the manual
they do not recommend alcohol and water on the centers because of the danger
of over-shrinking as well as the deleterious effects of alcohol on the ABS
Styran.

What they DO recommend is a mixture of 8 parts naptha to one part mineral
oil applied directly to the bushings. Another method (they say) is to remove
the action from the piano, apply silicone spray (!) to each tight bushing
using a plastic extension tube, followed by WD-40 (!!) applied in the same
manner. After that, they suggest making a "tent" over the action with
newspaper to form a "wind tunnel" and blow hot air from a hair dryer through
it for half an hour or more. If it's STILL sluugish, repin with the next
size larger pin. They don't mention how to remove all the junk that would
now be EVERYWHERE, including the silicone molecules which will now be
attached to almost everything in your shop let alone all the action parts!

I have run into more than a few Kawai verticals that wouldn't check properly
because the back checks and catch leather were too slippery. I wonder if
overspray or creep from this silicone treatment has caused this?  I won't
keep silicone spray (or anything!) in my house, let alone have in in the
workshop.  Does anyone know if Kawai still recommends this procedure?

Also, does anyone know what effects Protek has on the ABS flanges? Is it
safe to use?

Finally,  the black "carbon jack" Kawai uses is made from carbon and
polyacetal according to the spec sheet on it. It's a different material from
the flanges as the carbon also acts as a lubricant for the jack.

>   Any help would be appreciated.

Is that more than you wanted to know?  B-})

                        John
John Musselwhite, RPT
Calgary, Alberta Canada
musselj@cadvision.com