Thought that a brief outline of the above for our newcomers may be of interest
Since the record industry is well over 100 years old, however brief one wants to make it so as to be of any value it will still take a few installments, so it will be done as such
I am not going to go into fine details Just some dates methods as well as material used from the earliest to current methods of producing Record stampers
OK
The method of producing record stampers is the oldest as well as the most continious operation of the Electroforming industry
Until the 1980's it was also the most sophisticated in regards to the application of new technology in which area the record industry did lead
The high level of refinement reached in the record stamper industry was adopted in other areas of Electroforming such as the aeronautics, space, telecoms wave guides as well as the microelectronics, and general electronics industries, as an example flexible and solid printed circuit boards as well as early computer memory called "core"
Phonograph Cylinders
It is well known that these where produced by recording and rerecording
Up to five machine where grouped together for a singing session or up to ten for a band so by the end of the days session they had 3-400 cylinders done
The next step was to gang up master and slave machines so as to get some copies done from a master to the slave. Before the original was worn out up to 25 odd copies could be made from each original cylinder
In effect in a couple of days the could have produced about 1000 cylinders
There is an early reference to electroforming of phonographic cylinders by a German manufacturer who used cocoa butter dissolved in alcohol to coat the sound grooves wound around the cylinder which was than made conductive by gold sputtering This was than used as a master so as to form an electroformed negative By casting a metal into it to produce a positive which could be played, the metal shrunk enough so as to slip out of the mould without ruining the grooves It was of course impossible to electroform a positive master from the negative so the impossibility of reproducing or duplicating the electroformed negative as it stuck to the inside Even ruining the negative so as to remove the positive did not help as the electroformed positive had to be teared off
We can see than that electroforming was certainly used as early as recorded sound on cylinders was invented
This marvelous man Edison took out a patent for gold sputtering them while spinning these cylinders in vacuum via a magnetic device so he did not have to deal with vacuum seals in the spinning shafts In so far as phonographic cylinders where concerned this method of producing them lasted till about 1930
Disc Recording
In about 1894 the first disc's where produced pressed in "Ebonite" These where made by stampers made from a zinc coated metal disc which was first coated with a thin layer of cocoa butter to act as a resist
Where the resist was scratched away the zinc was etched into a groove providing a positive By electroforming copper onto the etched disc a negative was produced which was used to press the ebonite records
In about 1897 shellac replaced ebonite and a few years later about 1900 the zinc gave way to electro wax.
A much smoother groove could be cut there without the rough etched groove obtained from etching the zinc coated plates
This was first coated with fine graphite to make it conductive it was then coppered so as to make a negative so as to press records from
Methods were quckly developed to electroform shels from one another so a supply of negatives was assured
As knowledge built up graphite was replaced by gold coated graphite which was replaced by gold or silver sputtering, they were replaced by wet silvering as well as vacuum metalising wax cut's in pure gold or silver This was so as to produce better masters from which to produce Mothers and than Stampers
Stampers were electroformed in copper as thick as 40 thou, in some plants they where faced with nickel and in some others in chrome straight on to copper in some cases known both. First a layer of nickel which adheres well to copper and than a layer of chrome on to the nickel for the same reason it adheres well to it, this was so as to extend their life
Some plants soldered a thick plate behind them so as to give them a solid base as well as providing a specific profile on the pressed record
The solder was also helpfull in blocking out any pores through the stamper that was hard to repair any other way
The shellac material used at the time being very tough on the stampers they neded as much support as possible
These were well known methods and practices until the late 30's
Most of the known processes in 1936 were described by Ollard at the time
The fickle waxes did serve the industry for a good while, besides, a variety of additives where developed over the years so as to deal with the crystaline structure of the waxes which produced the hiss commonly associated with the older pressings Addittives did reduce it considerably
Soaps non ferrous metal powders as well as other "secret" ingredients was added
It was about that time that lacquer coated discs where invented they where patented in England as well as the USA, wax was quickly replaced by the lacquer coated alluminum disc
This of course necesitated new methods of producing masters Vacuum metalising was not good as it sucked out or boiled off all the volatiles out of the lacquers
Wet silvering initially by dipping became the method of making them conductive to plating current
Cutting styli for the lathes in use for cutting on wax had to be redisigned so as to cut the tougher material, the shape of the cutting stylus was also altered to suit the lacquer disc's
Of course this bought a whole lot of other issues to the fore, as an example "horns" where inevitable in cutting either on wax or lacquers so de horning of the positives a practice well known for years become a rather specialised process
The reason was the the "Hill and Dale" cut on wax needed dehorning in the groove where with lacquers the horns besides being in the groove itself were also at either side of the groove right on the top surface, the cutting stylus "pushed" some of the material either side of the cut
The situation was much improved with the heated stylus but this was not until mach later around 1948 when the long playing record come about
This of course resulted in the cut being about half the width while the amount of material recorded was 4 times as much
Shellac was done away with, PVC compounds replacing it in very sort time
It was about ten years later that stereo recordings were released with again twice as much information on them
Stereo recording being a lab curiosity since about 1931
Of course all of these improvements where only possible to be put into production so long as the art of electroforming of the masters as well as stampers kept up with these developments
This was the case So thick copper stampers where replaced by thin Nickel the methods of silver dipping the lacquers was replaced first by twin spray guns and later by a single combination device
Some interesting diversions did take place in the time just and during the second world war
Iron electrofomed stampers were used in Germany in the late 30's due to lack of copper They produced a 16 thou master which gave birth to a 40 thou Stamper In the USA electroformed Iron masters and stampers were produced in the 50's during the Korean war
A little diversion here
The alluminium drives during the war in the USA of course managed to get rid of a whole lot of historical material recorded on instantaneous recorders or transcription discs
Audio Devices as well as other lacquer disc manufacturers, Wilcox as well as Presto promised 10 cents per lacquer master returned to them for the war effort
Besides what good was a recorded lacquer disc after it had served is purpose recording an advertisement that went to air or of a news item that was distributed to other radio stations in a syndicated news service
Back to the theme,
The use of iron was of course a temporary measure at the time when things went back to normal the development of all Nickel masters and stampers went ahead even though quite a few manufacturers stuck it out for a while with copper They ultimatelly all went to an all nickel method by the mid 60's
Another installment here will describe the various methods as well developments with Nickel The practices as well as some description of the systems used in a few plants around the world as well as improvements in the art
(Additons, Comments and filling of Gaps will be definately needed So any input from others will be most welcome)
Cheers
Moss, I'm not quite sure I understand your description of the Edison "gold molded" cylinder record process. Prior to that, a mechanical duplication process was used by most cylinder makers that involved the use of a completely mechanical duplication system known as "pantographing". The process involved a mechanism that could carry one master recording and make up to 5 or 6 duplicate records at a time. The cylinder record blanks were loaded into the duplicator, each of which was set up with a cutting stylus mechanically linked to the playback stylus on the master. This was purely mechanical - not an acoustic system involving a reproducer playing the master and coupling by air pressure to a system of recorders with diaphragms. Record made with this system were generally made of a soft brown wax material which did not wear well.
This mechanical system was not satisfactory as only a few duplicates could be made from each master before the master was worn out. So, yes, Edison developed a gold sputtering process of the wax master (the origin of the term "gold molded" which Edison used as a trademark on all his later commercially sold wax cylinders - the term is prominently displayed on the retail cylinder boxes). This conductive master was then used to electroform a metal negative. This negative could either be used as a "mold" (Edison's term), or stamper to directly mold wax records, or it could be used to mold secondary "masters", each of which could be further gold sputtered and used to make more molds for record production. The "wax" (really a metallic soap compound) that was poured into the record molds would shrink sufficiently upon cooling to allow the record to be removed from the mold. These materials were now black in color and were harder which allowed better wear performance. The amount of shrinkage in this material was carefully controlled in the formulation of the compound because it was necessary to INCREASE the size of the grooves and widen the recording pitch during mastering to allow the finished, shrunken record to conform to the standard dimensions of the player mandrel and the playback feedscrew which was standardized at 100 LPI (lines per inch) for 2 minute records and at 200LPI for 4 minute records.
To digress for a moment, yes, Edison actually invented the microgroove record back in 1908 with the introduction of the 4 minute, 200 LPI cylinder. He also invented the long-life diamond stylus with which to play these as well as his "diamond disc" records, introduced in 1912. This 4-minute LP became the common format from then on to 1929, so a very many of them were made. You will note that the average pitch of the modern LP is still around 200 LPI. Then Edison topped himself with the introduction of the 450 LPI "long playing" Diamond Disc record in 1926 which still turned at 80 rpm. RCA marketed a consumer record at 33-1/3 rpm that they called "program transcriptions" and several models of players to play them in 1931 - 32, as did a few other manufacturers. So much for Columbia having anything to do with "inventing" the LP in 1948.
Back to cylinders: Later Edison (as well as Columbia, US Everlasting, and Albany Indestructible brands) cylinder records were made of celluloid. This process was similar to that used for making wax records in that electroforming was used to make the molds. The celluloid was purchased from the Celluloid Company already extruded in long thin tubes. It was a milky white color and was dyed by the record manufacturer to whatever color they wanted. Most of the makers typically used black, but some of the Indestructibles are found in grey and light blue. Edison decided to use a deep blue color, for which he named his records "Blue Amberols". A few of the high-priced Edison operatic records in the 29000 series were made in a dark magenta color and were labeled "Royal Purple". The dyed tubular celluloid was then cut to shorter lengths which allowed each piece to be put into a record molding machine. A rubber bladder was inflated to support the inner surface of the celluloid tube and expand the heated plastic against the grooved surface of the mold while steam heated the mold. After molding, water was used to cool the mold, the bladder was deflated, and the piece of celluloid shrank sufficiently to be removed from the mold. The process was very much the same as is still used in the manufacture of automotive tires. The flimsy celluloid tube was usually fitted with a core of some kind to allow it to fit correctly on the mandrel of the player. Only the Lambert cylinders were molded with a plastic rim on each end that would support the cylinder on the player without the use of a core, but that method was not really satisfactory. Edison filled his records with a plaster material as a core (first dyed a dark color, then later left the natural white), Everlasting used an asphalt material, and Indestructible used a cardboard tube with formed steel rings on either end as a core to support the thin celluloid.
This mechanical system was not satisfactory as only a few duplicates could be made from each master before the master was worn out. So, yes, Edison developed a gold sputtering process of the wax master (the origin of the term "gold molded" which Edison used as a trademark on all his later commercially sold wax cylinders - the term is prominently displayed on the retail cylinder boxes). This conductive master was then used to electroform a metal negative. This negative could either be used as a "mold" (Edison's term), or stamper to directly mold wax records, or it could be used to mold secondary "masters", each of which could be further gold sputtered and used to make more molds for record production. The "wax" (really a metallic soap compound) that was poured into the record molds would shrink sufficiently upon cooling to allow the record to be removed from the mold. These materials were now black in color and were harder which allowed better wear performance. The amount of shrinkage in this material was carefully controlled in the formulation of the compound because it was necessary to INCREASE the size of the grooves and widen the recording pitch during mastering to allow the finished, shrunken record to conform to the standard dimensions of the player mandrel and the playback feedscrew which was standardized at 100 LPI (lines per inch) for 2 minute records and at 200LPI for 4 minute records.
To digress for a moment, yes, Edison actually invented the microgroove record back in 1908 with the introduction of the 4 minute, 200 LPI cylinder. He also invented the long-life diamond stylus with which to play these as well as his "diamond disc" records, introduced in 1912. This 4-minute LP became the common format from then on to 1929, so a very many of them were made. You will note that the average pitch of the modern LP is still around 200 LPI. Then Edison topped himself with the introduction of the 450 LPI "long playing" Diamond Disc record in 1926 which still turned at 80 rpm. RCA marketed a consumer record at 33-1/3 rpm that they called "program transcriptions" and several models of players to play them in 1931 - 32, as did a few other manufacturers. So much for Columbia having anything to do with "inventing" the LP in 1948.
Back to cylinders: Later Edison (as well as Columbia, US Everlasting, and Albany Indestructible brands) cylinder records were made of celluloid. This process was similar to that used for making wax records in that electroforming was used to make the molds. The celluloid was purchased from the Celluloid Company already extruded in long thin tubes. It was a milky white color and was dyed by the record manufacturer to whatever color they wanted. Most of the makers typically used black, but some of the Indestructibles are found in grey and light blue. Edison decided to use a deep blue color, for which he named his records "Blue Amberols". A few of the high-priced Edison operatic records in the 29000 series were made in a dark magenta color and were labeled "Royal Purple". The dyed tubular celluloid was then cut to shorter lengths which allowed each piece to be put into a record molding machine. A rubber bladder was inflated to support the inner surface of the celluloid tube and expand the heated plastic against the grooved surface of the mold while steam heated the mold. After molding, water was used to cool the mold, the bladder was deflated, and the piece of celluloid shrank sufficiently to be removed from the mold. The process was very much the same as is still used in the manufacture of automotive tires. The flimsy celluloid tube was usually fitted with a core of some kind to allow it to fit correctly on the mandrel of the player. Only the Lambert cylinders were molded with a plastic rim on each end that would support the cylinder on the player without the use of a core, but that method was not really satisfactory. Edison filled his records with a plaster material as a core (first dyed a dark color, then later left the natural white), Everlasting used an asphalt material, and Indestructible used a cardboard tube with formed steel rings on either end as a core to support the thin celluloid.
Collecting moss, phonos, and radios in the mountains of WNC
Masters
Hey Cd4Cutter
Have to say your description is perfectly correct and quite detailed in so far as Edison Cylinders are concerned
I was not intenting to describe methods of production as such except where electroforming was involved
May be it is not clear enough however it has nought to do with Edison
It was a German process and that is clear enough
The reference is a Pfanhauser version of those days published in "Galvanotechnik Vol 2, Leipzig 1949/50, p 1424
It was not to make them, the cylinders, from wax or metalic soap material or cellulose or whatever else but from some metal
Pfanhauser was a major player in record matrix production with facilities in Neuss/Rhein, Germany, Langbein-Pfanhauser Werke AG
They use to run 2 or more banks of baths with 12 and 6 cells per bank in the 70's most likely pre plate and high speed finishing off
They did very early work as can be seen by the above
Cheers
PS:looks like like you have gathered me as well, reffering to moss
Have to say your description is perfectly correct and quite detailed in so far as Edison Cylinders are concerned
I was not intenting to describe methods of production as such except where electroforming was involved
May be it is not clear enough however it has nought to do with Edison
It was a German process and that is clear enough
The reference is a Pfanhauser version of those days published in "Galvanotechnik Vol 2, Leipzig 1949/50, p 1424
It was not to make them, the cylinders, from wax or metalic soap material or cellulose or whatever else but from some metal
Pfanhauser was a major player in record matrix production with facilities in Neuss/Rhein, Germany, Langbein-Pfanhauser Werke AG
They use to run 2 or more banks of baths with 12 and 6 cells per bank in the 70's most likely pre plate and high speed finishing off
They did very early work as can be seen by the above
Cheers
PS:looks like like you have gathered me as well, reffering to moss