- Getting the Ingredients -
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At this stage of the investigation, the most difficult question
on my mind was exactly what ingredients would be needed in order
to do some first experiments making cylinder wax.
It was rather confusing. I will begin this segment by bringing the
reader all of the information I had at that time, so that the
confusion can be seen. All I had as a reference was the hand-copied
transcription from the book "Technical Handook of Oils, Fats, and Waxes"
by Fryer and Weston, 1939. Here is what it says:
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Pure Stearic Acid 12 pounds
Caustic Soda 1 pound
Aluminum Oxide 1 ounce
Tempering (ceresin or paraffin) 2 pounds
The caustic soda is boiled in about twice its weight of water,
at which point the aluminum oxide is added. The soda lye is now
added to the stearic acid, which should have already been melted,
and the whole is kept cooking until all the water from the soda is
driven off. When this is clear, the tempering is added. The whole
is then further heated; the temperature should be about 450 degrees F.
(not more for fear of flashing). This then is strained, lowering
the temperature by about 100 degrees F. The mixture is then ready
for the moulds. It is not quite suitable for master records, but it
is good for direct reproductions.
Moulding Operation:
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The core and cylinder are assembled after treatment with graphite
or french chalk; they are dipped together into the molten preparation.
The mould stays under for some time so it becomes gradually heated
by the mixture and thus, retention of air bubbles is avoided.
After a time the mould is lifted out, drained, and set to cool.
The conical mouth retains a "head" of wax to flow into the lower stratum
when cooling.
At a certain stage of cooling (to be determined only by experience),
the core is loosened and twisted out. If allowed to remain too long,
the wax will contract and bind the core too tightly for removal.
The outer cylinder containing the blank is allowed to cool completely,
when the latter will easily slip out. The interior of the cylinder
is then reamed out, and the head gets cut off. Then the cylinder
is shaved.
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The above is all I had to work from at that time. I had asked around
a bit and found several wax companies and chemical companies that
have active, aggressive sample programs available to researchers
who are working on new processes. The stearic acid was fairly easy
to obtain using that method. So was the ceresin. The caustic soda
is just lye (more properly called sodium hydroxide or NaOH).
The lye was, in fact, the first ingredient found and purchased.
I just simply picked up a 1 pound bottle of lye at the local hardware
store.
Soon, the stearic acid and the ceresin arrived as free samples from
a few different chemical companies.
That left the aluminum oxide, which turned out to be the first of
several stumbling blocks. The thing about aluminum oxide (Al2O3)
is that it's the same stuff found in sandpaper! It is very hard
and abrasive, just the wrong stuff to have in cylinders. I was
seeking any and all information about why it is there in the cylinder
wax, as to what function it serves. Along the way I read some things
that hint that some of the early wax recipes called for it, and some
even described how to make it. One such account tells about burning
aluminum metal and using the fine ash that is the aluminum oxide.
So I investigated and dug deeper and asked around several chemical
companies for aluminum oxide and found out that not only is it fairly
uncommon, but that when found it is rather costly.
The story of the aluminum oxide in the cylinder wax apparently
comes down to the fact that once it is all combined in with the
other ingredients, it is no longer harsh and abrasive. It combines
with the stearic acid to form aluminum stearate, which is a salt
and which has favorable properties in a recording blank. Adding it
in as a fine powder such as would be obtained from burning aluminum
apparently causes it to combine readily, and so the abrasiveness
is avoided. The big danger in using aluminum oxide is that if
any of it is left uncombined, it will wear out shaver cutters,
recorder cutters, and playback styli, not to mention that the blank
will sound harsh and noisy.
The big realization came when I found out that the aluminum metal
itself is why the aluminum oxide is there in the first place. Just
because the aluminum is bound up with oxygen to form aluminum oxide
gets away from the fact that what is needed is the aluminum metal
itself, leaving the oxygen as just extra and un-needed.
One other perfectly good way to achieve the same chemical result
is then, simply, to use pure aluminum metal instead of the Al2O3.
It also turns out that lye readily reacts with aluminum, which is
very handy in this formula. The end result of this part of the
investigation was that no search for aluminum oxide was required after
all. The aluminum was readily available on the roll of aluminum foil
in the kitchen drawer!
So, finally the day came when all the ingredients were spread out
on the dining room table, ready to be used. Great stuff! But, what
to do with them?
Next segment: Early Experiments
