Klarinet Archive - Posting 000096.txt from 2004/02
From: Tom.Henson@-----.com
Subj: [kl] Shellac on Tone Hole Faces-tips
Date: Mon, 9 Feb 2004 16:47:01 -0500
I tried an experiment over the weekend that I wanted to share with the list.
A while back I had searched the archives for anything matching Hans Moennig.
I was hoping to find out more information about what he did and how he
actually did it from people that would know.
I got a lot of matches on a gentleman by the name of Alvin Swiney. Most of
the message were back in 1999 and a few in 2000. Evidently he does not post
to the list anymore, but his knowledge of working with Hans really intrigued
my.
Specifically, I read where Hans would throw away 90% of the commercial pads
that were available to him. He became so frustrated that he started making
his own skin pads for his top level work. This figure astounded me. In
addition, Avlin said that he also used several coats of shellac on the tone
hole faces to help build up a smooth layer of material on which the pads
could seat better. The shellac would fill in the microscopic imperfections
such as grain lines, grain holes, etc.. Alvin also said that Hans' vacuum
test of a good pad seal was 3 minutes for the upper joint and 75 seconds (1
minute 15 seconds) on the lower joint. The lower joint having a shorter
time, I suppose, due to the larger tone hole and pad size. These were the
times that he achieved and I'm sure that even by today's standards that is a
lot. However, I don't know if Hans ever worked with a synthetic pad like the
Valentinos. Therefore, I did an experiment.
Using an R13 with the Valentino Greenbacks (which are made of a synthetic
material), I wanted to try the shellac method with a clarinet that I knew
was already in good condition to see if any improvement could be achieved.
Before the shellac, I was able to get about 30 seconds on the upper joint
and about 1 minute on the lower joint. The upper joint also has a key that
is going to be replaced due to excessive wear and therefore may be one
reason for this lower vacuum time. I don't know if these time are average or
not for this type of pad or clarinets in general. Maybe someone with repair
experience could comment.
I took the clarinet apart and inspected the tone holes without any
magnification, just by eye. My particular specimen has quite a bit of grain
in the wood, mainly along the tone holes on top. You can clearly see the
grain lines that run through the tone holes and chimney's. The lines are not
really deep, but there are there nevertheless. I also found a couple of tone
holes that had some small imperfections.
I went down to the hardware store and bought a small can of clear shellac
for about $5. If you try this, make sure it is the clear shellac.
To prep the tone hole faces to make sure they were clean, I took some Q-tips
and soaked one tip in alcohol. I cleaned the face with the alcohol first and
then used the other side to dry it. I used quite a few Q-tips as they would
get dirty pretty fast.
Then, using a small artist bristle brush, I applied thin coats of the
shellac undiluted. Shellac, by the way, can be diluted with alcohol. That is
one of the main ingredients. After I had "painted" all the tone holes of one
joint, I went back with more clean Q-tips soaked in alcohol and carefully
insert it into the tone hole and twist it round to remove any excess shellac
that had dripped into the tone hole itself. I didn't want to apply it inside
as this would change the tuning and voicing of the tone hole slightly. You
must be careful not to get any cotton fibers stuck on the shellac and dry. I
used small tweezers to pull a few off that had stuck to the face. I applied
a total of three coats. In between each coat, you need to wait at least 2
hours for it to dry completely. I actually waited about 3-4 hours. The
shellac will dry completely clear and will have a somewhat shiny look to it
like varnish. Don't be alarmed that you can still see all the grain lines
and imperfections showing through, this is because it is clear and you can
see everything on the tone hole face.
In addition, I applied three coats of shellac to the end grain of the upper
joint and the bell tenon on the lower joint. I didn't want to apply it
inside the sockets as I was concerned it would make them too tight. Besides,
it would probably wear off in time anyway due to the friction of putting it
together. I used the Doctor's wax in the sockets to help waterproof them.
Once I had completed all three coats and let it dry properly, I then put the
keys back on. I paid very close attention to how each cup/pad would contact
the tone hole surface making any minor adjustments to make sure they closed
flat and even against the tone hole face. I did not use any special tools
for this other than my eye and my hands.
Having it all back together I started test playing it. All I can say is that
the difference was immediately apparent. Each note played with ease and with
fluidity and evenness. The whole clarinet seemed easier to play as well,
like it had less resistance. I checked the tuning to make sure that it was
still correct and it was. The tuning was not affected by this process.
Now for the figures. Using only my hands and mouth to do a vacuum test here
are the results:
Lower joint - 4 minutes (I was shocked!)
Upper joint - 1 minute (I need to replace one key that I think is not
seating properly and is loose).
While I had hoped for the magical 3 minutes on the upper joint, I think I
know what is holding it back. At least I doubled the time of the vacuum
seal.
What I could not believe was a 4 minute vacuum seal on the bottom joint.
That is almost 3 times longer than what Hans Moennig ever hoped to achieve
on a regular basis using skin pads.
While all of this is not scientific in approach, it confirms to me at least,
that there is some benefit in using this shellac treatment of the tone hole
faces. Given that it only cost me about $5 and took about three hours of
total work, not counting the waiting between coats, I don't know why more
people don't do this. As a matter of fact, why don't more repair techs use
this method for achieving a tighter seal and a longer vacuum number?
Tom Henson
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