Klarinet Archive - Posting 000207.txt from 1997/02

From: "Robert D. Shaw" <theshaws@-----.NET>
Subj: Re: Keeping a clarinet warm
Date: Fri, 7 Feb 1997 20:50:33 -0500

Mark,
I wholeheartedly agree with all of your comments about cracking and
have taken steps to do these things ever since I bought my R13 1 1/2
years ago. I have been extremely faithful about oiling my clarinet,
keeping it at a steady temperature and warming it slowly before
playing. However, my efforts have been in vain, because my instrument
developed a crack above the register key recently. Luckily I caught it
while it was still a surface crack and had it repaired by a wonderful
technician. Sometimes you cannot win!!
On the other hand, I have had friends who have not taken care of
their clarinets for years and they have not had any problems.
My luck has not been good, but that will not stop me from taking
good care of my instrument. Hopefully it will be a great instrument for
years to come.

Deborah Shaw

Mark Charette wrote:
>
> I've been lightly chided for a very frivolous answer to a very
> serious question, and rightly so. So, as penance, I will relate a
> little bit of my material properties background to the subject, but
> without the math (because I don't have all the gross properties
> for grenadilla in my CRC handbook ;^)
>
> Materials crack or split for various reasons, but all have to do
> with the release of internally stored energy. A crack wants to
> start at some defect in the material because it's an area where
> the energy can easily be dissipated, and the crack spreads because
> there is more energy "behind" it trying to get out.
>
> All materials have some sort of "glue" which hopefully is stronger
> than the energy trying to split it. In wood, the fibers are interlocked
> and hopefully the defects are few, along with the wood being in a
> "relaxed" state.
>
> Cold weather, however, changes two things dramtically. One is the
> relative humidity. Wood is not dimensionally stable with varying
> humidity levels, and heating a home changes humidity levels drastically.
> As the wood shrinks, internal stresses build, and make it more likely
> that the wood will get rid of it's stored energy along some defect.
>
> The other, of course, is the temperature change. Wood is not
> dimensionally stable as regards temperature, either. Add to that
> the changes brought about with unequal heating (when you start playing
> the instrument) and you have the receipe for disaster.
>
> How to avoid the problem? One obvious way (which I have no empirical
> evidence for) would be to seal the wood, using whatever bore oil your
> tech recommends (I don't know what's best, but there are some
> recommendations on the sneezy pages). The oil polymerizes in the pores
> of the wood to create flexible plugs - the wood can expand and contract
> due to temperature changes, but the internal humidity levels (internal
> to the wood) should stay more constant).
>
> Another obvious way is to keep the clarinet from expanding and
> contracting too quickly. Taking it out and throwing it into the
> trunk of a car in the winter is not going to be a good idea, along
> with sticking it by the heater vent! A good, solid case with a
> reasonable amount of foam surrounding the instrument would
> theoretically be a "good thing". Wrapping it in aluminum foil will
> also make a large difference (shiny side in or out? - I've done
> experiments both ways with my kids, and there is negligable
> difference either way, and whether you're keeping something hot or
> cold). The aluminum foil thing during experimentation added about
> 20% efficiency (in temperature differentials after 2 hours) to 1" of
> expanded close-celled polystyrene foam. We tested foil next to the
> object as well as foam next to object - the results were statistically
> insignificant.
>
> The last thing - don't ever blow into a cold clarinet! The clarinet
> may be 60 F., your breath 95F., and the 35F differential can split
> the wood with NO problem at all!
> --
> Mark Charette Webmaster, http://sneezy.mika.com and maintainer of
> Mika Systems, Inc the Clarinet Info Pages,
> charette@-----.com/clarinet