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Note: In 1920, with sales of Diamond Discs at an all-time high (see
Edison Disc Record and Phonograph
Statistics), the Edison factory found it hard to meet demand
for the records.
Paul Kasakove was hired to develop new processes that would shorten
the disc production cycle. The following are his recollections.
Particularly interesting is Kasakove's observation that only one
of the usual three takes was chosen for issue, with the other two
takes held in reserve for "emergency" use. This refutes
the often-repeated (and incorrect) statement that all three takes
of any given Edison master were automatically issued.
Edison
Diamond Disc Records (Hill and Dale) Manufacturing Processes as
of 1920 to 1929 from Wax Masters to Condensite Records
By
Paul B. Kasakove (July 1964)
Electroplating
Process for Disc Record Moulds
In July 1920, I was engaged by Mr. T. A. Edison to modernize the
entire process for making the nickel-faced copper moulds that were
used, to press out the disc records. It was taking approximately
three weeks from the time the newly recorded Wax Masters were delivered
to West Orange from our New York Studio, before the first prints
from the Wax Masters could be heard. As a result of the experimental
work by Mr. T. A. Edison and myself, the process was changed so
that the three-week period mentioned above was reduced to three
days. The first disc record made by this improved process is on
display in Mr. Edison's library.
This improved process remained in use right up to the tine the Disc
Record Manufacturing Division was shut down. It may be described,
as follows:
1. The Wax Masters were recorded in our New York Studio and delivered
to the plant at West Orange in the evening of the same day that
the recordings were made. Mr. Walter Miller, who headed our New
York Studio at the time, and who lived in West Orange, would usually
bring the Wax Masters in on his way home. It was the practice to
make three Wax Master Recordings for each selection, and they were
identified by a serial number and the letters A, B, and C.
2. On the morning following the delivery of the Wax Masters, they
were turned over to the Plating Department employee who was responsible
for the grafiting [sic] operation. This grafiting process, the purpose
of which was to provide the recorded face of the Wax Master with
an electro conductive surface, had replaced the gold coating process,
because it saved a full day's time. At first, the grafite [sic]
that was used to coat the wax was purchased: as ordinary commercial
grafite, and subjected to an elaborate purification process which
consisted of fusing the grafite with caustic soda, then dissolving
out all the impurities, rinsing thoroughly in distilled water, with
a final rinse in pure grain alcohol. Later I discovered a small
company in Connecticut that specialized in making and selling grafite,
purified for electroplating purposes, and I vas able to buy this
grafite cheaper than I could purify it myself, so we discontinued
the purification process. The grafiting of the Wax Masters took
only a few minutes. They were placed on & table which could
be made to revolve slowly while being brushed with a very fine silk
bristle brush saturated with grafite, which just barely touched
the face of the Wax Master. At first My Edison was somewhat concerned
that this brushing action might result in removing some of the wax,
thereby causing poor reproduction. However, I was able to reassure
him by letting him listen to and inspect two records of the same
selection one made by the old Gold Coating Process, and one by the
grafiting process described above. He was unable to see or hear
any difference. When the grafiting of the Wax Masters was completed,
they were brought down to the Master elating Room located just below
the Grafiting Room in the same building, (22A).
3. As soon as the Grafited Wax Masters were received by the man
responsible for the copper plating of the masters (Peter Dempsey),
he would mount each Wax Master on a suitable, specially designed,
plating holder, which permitted the master to be rotated while semi-submerged,
in a Copper Plating Bath, with the electric current passing from
a Copper Anode in the bath through the Copper Sulfate-Sulfuric Acid
solution to the grafited face of the Wax Master, depositing a coat
of copper on to the grafited face. It formerly took several days
before the deposited copper was heavy enough (about .030")
to be stripped from the Wax to be used as the Copper Master. However,
we were able to cut this time down to 24 hours or less. As soon
as the recorded face of the Wax Master was completely covered with
Copper, an operation that took about four or five hours, the Wax
Master and holder, were transferred to another bath, which was a
cylindrical hard rubber pot containing a more concentrated copper-plating
solution, and in this bath, the Wax Master was suspended face down,
and completely submerged. In the bottom of the hard rubber pot was
a Copper Anode. By increasing the concentration of the Copper Sulfate
solution to permit higher current densities, and by rapid circulation
of the solution between the plating baths and the central storage
tank, the Copper Masters were heavy enough for stripping from the
Wax the following morning.
4. When the Copper Master plated to the Wax Master had reached the
proper thickness, the plated Wax Master was delivered to Mr. Frank
Clancy, Supervisor of the Lathe Department on the 3rd floor of Building
24. Here it was mounted on a Lathe, the outer edge turned down until
the line of separation between Wax and Copper became visible, and
then the Copper Master was stripped from the Wax. The Wax was returned
to the Silver Lake Wax Department for remelting. The Copper Master
would have a brass lug soldered in the center of. the back of the
mould and returned to the Plating Department.
5. In the Plating Department, the first step was to place the Copper
Master face up on a turn-table of a polishing machine, so designed
as to permit the turn-table to rotate, while a circular brush, fed
with a rouge polishing compound rotated slowly, with the bristles
in contact with the face of the Copper Master. Although this polishing
operation produced a completely clean surface on the face of the
Copper Master, it did not affect adversely the sound reproduction.
6. After polishing, the Copper Master was mounted on a Mould Holder,
placed in an electro-cleaning bath (a Sodium Sulfate solution),
for about two minutes to insure a chemically clean surface, rinsed
in distilled water, and then immersed in the "8-4" solution
and rotated for about two minutes. It was then removed; rinsed again
in distilled water, and placed immediately, while still wet, in
the Nickel Plating Bath.
7. The Nickel Plating operation under the old process required at
least ten hours to get the required thickness of coating (about
0.0004"). By increasing the density of the Nickel Plating Solution
using Glacial Ascetic Acid to improve conductivity, and immersing
the Copper Master in the solution face down instead of semi-submerged
as was previously done, and using Nickel Shot for an anode instead
of a solid cast anode, the total time required to get the desired
thickness of nickel was reduced from ten hours to two hours. The
Nickel. Shot was contained in a hard rubber, round, tray at the
bottom of the hard rubber cylindrical plating bath, and was periodically
removed from the bath and washed free of the Nickel Sludge which
is formed during the electroplating process. The sludge was replaced
by new Nickel Shot Additional changes made to speed up the Nickel
Plating consisted of raising the temperature of the Nickel Solution
to about 120°F, and circulating it rapidly between a central
storage tank and the individual plating baths. As a result of these
various changes, we were able to reduce the plating time from ten
hours to two hours. Because of the increased current density, there
was a tendency occasionally toward the formation of an excess of
Hydrogen gas bubbles to be re- leased, which if allowed to settle
on the face of the mould being plated would result in a series of
small holes in the plating. To prevent this, we added some hydrogen
peroxide, which combined with the excess Hydrogen to form water.
8. After two hours in the Nickel Plating Bath, the Copper Master
was removed from the bath, rinsed quickly and thoroughly, and transferred
without any delay into the Copper Plating Bath, which was also a
cylindrical hard-rubber pot, with a specially designed copper anode
at the bottom of the pot. The Copper Master, attached to its Mould
Holder, was suspended face down in the Copper Plating Solution in
this pot, and rotated rapidly with the current on. The cast copper
anodes used for this high speed copper plating process were made
in our own copper foundry located in the rear of Building 1, and
were so designed as to permit of a maximum surface facing the cathode
(master) and also to permit the Copper Sludge which was formed in
the plating process to be washed to the bottom of the plating bath
by the circulating copper plating solution. The copper plating solution
was stored and heated in large crocks from which it was pumped and
fed individually to each Copper Plating pot. Since any interruption
in the electro-plating before the desired thickness of copper was
obtained would spoil the mould, it was necessary to guard against
such an interruption by having available at all tines an emergency
source of current. This was accomplished by keeping a sufficient
number of Edison Nickel-Iron Batteries in a separate room in Building
22A. These batteries were connected in such a manner as to permit
of an immediate switch in the event of a power failure. The electroplating
process was continuous, 24 hours a day, seven days a week. I was
on call at all times in the event that anything went wrong with
the process.
9. On the morning following the start of the copper plating of the
female to the Copper Master, the Master with its plated female was
removed from the Copper Bath and its holder, washed, dried, and
delivered to a room adjacent to the plating room. Here a trained
lathe operator turned down the beaded copper plated edge, until
the line of separation between the nickel face of the female, and
the Copper Master, became visible. Then on a machine specially designed
by Sam Moore for this purpose the Master and female were separated
cleanly, without in any way marring the surface of either one. The
time required for making a Female from a Copper Master totaled about
24 hours as compared with a minimum of three days by the old process.
10. The Nickel faced Female Mould, after stripping from the Copper
Master, was sent up to Mr. Clancy on the 3rd floor of Building 24
where a brass lug was soldered to the center of the back of the
mould, so that it could be screwed to the Mould Holder, and returned
to the Plating Department. Here it was given a quick polish similar
to that given the Copper Master, but since the Nickel face was so
much tougher than the copper face on the Master, the polishing compound
in this case consisted of a fine emery paste. After polishing, the
female mould was put through the same cycle as the Copper Master,
as described above; i.e., Electro-clean, Rinse, Rotate in "8-4"
Solution, Rinse, Nickel Plate 2 hours, rinsed and place in Copper
Plating Bath until the following morning. It was then removed, the
plated mould stripped from the Female, and sent up to Mr. Clancy
to be finished to glass-like smoothness on the back, so it could
be used to press out the male recording on its nickel face, on to
the Disc Record Blanks. This was called the Working Mould, and if
properly handled could print several hundred Disc Records.
11. The complete cycle as described above, from the receipt of the
Wax Master Recording to the completion of the Working Mould, could
be repeated as many times as necessary to print the number of records
needed for sales. The Copper Master could produce about ten Females.
Each Female could produce at least a dozen Working Moulds, and if
by any chance something happened that would interfere with the completion
of the number of moulds needed, it was always possible to start
with one of the other two Wax Masters kept in the Vault for emergencies.
12. All three Wax Masters on a given selection were put through
the above cycle so that at least one print from each Master could
be listened to by our Music Committee, of which Mr. Thomas A. Edison
was a member, and this Committee chose one of the three for production.
However, to insure that nothing happened that would cause any deterioration
with the face of the Copper Masters, I arranged that after they
were no longer needed for immediate use, they were put through the
plating cycle again, but were not separated from the plated female.
The Copper Masters with the female mould plated to them for protection
were stored in the Vault for possible future use and safe keeping
— Paul B. Kasakov (July 2, 1964)
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