From: Snaruhn@xxxxxxx
To: harp-l@xxxxxxxxxx
Subject: [Harp-L] Warming harps (was:.. CX-12 Chromatic 'Sticks' )
Date: Wed, 22 Dec 2004 15:57:53 EST
Vern wrote:
< While warming is not sufficient to avoid all sticking/popping,
< it does prevent the condensation that occurs against a plate that
< starts at much lower than breath temperature. >
Sorry, Vern, but that´s the crucial question: how much lower...?
I say, not much lower, exactly spoken, an object must have the same
temperature to prevent condensation. A well-known example may illustrate
that.You will certainly agree that spectacles on the nose have almost taken
on body temperature, but it´s possible though to have the breath
condensates
on the glasses for cleaning.
You have to carry a harp in the pocket for hours until it is warmed up to
body temperature. In the moment you pick it out the cooling down starts
immediately together with the condensation effect.
Our breath has certainly a moisture content of 100% and the body
temperature let´s assume with 65° F.
When I´m tuning reeds I always wonder again that a single blow is enough
to produce Niagara Falls on the reed AND it doesn´t matter that I´ve
warmed the reedplate with a hair drier before.
In my last post I said.
<< .....to warm up a harp for better function is superfluous in case of
blow
<< reeds because the breath is warm enough and ineffective in case of
<< draw reeds because the inhaled cold air immediately balances the
<< warming.>>
Aaah, I thought over that (I constantly think about past things, heehe) and
found that the matter is even more complicated. At a blow one doesn´t warm
not only the blow reed but, logically, also the backside of the draw reed.
The same goes for draws, only the other way round. A chamber has a blow
and a draw reed, so, they are both cooled by the cold inhaled air. In other
words: Blow and draw reeds are alternatively warmed and cooled depending
on the tune being played.
The fact is interesting indeed that the blow valves are mostling popping or
curling or are making other nonsense. Yup, one reason is clear:
When the frustrated chromaticist removes the comb out of the shell to look
for the malefactor he doesn´t care much of the paper tigers and, orrps,
again
he as one killed or is gone by the wind (therefore: windsaver).
But other reasons are obvious too. Though both reeds in a chamber are
alternatively warmed and cooled, the blow reeds are the ones which
can "enjoy" the breath moisture.
Now Vern again:
< It is my experience that warming combined with engraving and waxing
< the plate surface around the blow-reed slots eliminates
sticking/popping. >
OK, forget the warming but the other measures are well-thought. Above all,
the engraving is effective because it diminishes the adhesion of the wet
valve.
The popping and curling valves aren´t unknown to Hohner but the factory
didn´t find a satisfying solution over the decades though there are good
alternatives (found in the archives). Hohner once introduced a harp-like
wind
instrument where the playing wind didn´t get immediately to the reeds but
in a detour, similar a bagpipe is working.
Once I asked Toots what he would do when his Mellow Tone suddenly
started to make strange popping noises on stage. Nothing, he answered,
or do you think I would stop playing only because of these trivial matters?
Finally, about all these condensation, warming, and popping problems the
millions of blues harpers can only laugh, unless, they valve their
mini-harps.
Oh, I almost forgot to mention an important point. When I saw the Niagara
Falls on the blow reeds though warming them, I thought at first that the
water may influence the pitch which had been a serious and almost
insurmountable barrier. However, two things prevent that:
1. A vibrating reed acts like a trampolin for water drops.
2. The relation of the densities of water and brass is 1 : 8.9 = the water
has no chance.
Siegfried