Klarinet Archive - Posting 000061.txt from 1994/05

From: Clark W Fobes <reedman@-----.COM>
Subj: Re: Clarinet Materials
Date: Tue, 3 May 1994 12:53:54 -0400

On Tue, 3 May 1994, Chris Hill wrote:

> The "graphite" clarinet postulated in recent communications must surely be
> thought of as a graphite fiber/epoxy resin or carbon fiber/epoxy resin
> composite material, or some closely related composite. The stiffness of
> such structures can be quite finely tailored, depending on fiber content,
> the precise nature of the resin used, and other factors, so it should be
> possible to vary the acoustic properties, which depend sharply on
> stiffness, of a clarinet fabricated from them.

I have always believed that this ability to tailor the stiffness
of this material is one reason that would make this material so
suitable for a wood substitute
>
> Of course, plastic clarinets have been made for a long time, but I don't
> know whether aerospace composites have been tried. As in aerospace
> applications, however, the Achilles Heel of composites is usually in
> attaching fasteners and in weak places caused by drilling holes in them.
> Since a clarinet is a rat's nest of holes, both open and tapped for
> attachment screws, a composite horn might be very susceptible to cracking
> and to delamination of the material owing to water absorption.

This is a very interesting point that I had not considered. Being
a "resinous" material is this really susceptible to moisture?
Does this material have a greater propensity for cracking than
wood?
>
> I'd be interested to know if anyone knows of experience with composite
> clarinet construction.
>
> As to my colleague Steven Popper's cast aluminum-titanium clarinet, my
> hunch is that making them of sheet metals in the old fashioned way (as we
> make all brass instruments and the much-maligned metal clarinet) will
> remain both cheaper and more effective than near net shape casting.

As far as I know clarinets have never been cast except in the
plastic which is an injection mold process.

>
Clark W Fobes reedman@-----.com