Manufacture of Edison Records

[Edisone]

An article from 1912:

https://www.box.com/s/4ecskhw3dt2g3q08j89y

Note that trade secrets were being revealed, but only as the process was being abandoned in favor of celluloid Blue Amberols.

[edisonphonoworks]

I wonder when they actually started with these automatic molding machines? I have the formula and moulding instructions for Gold MOulded records from 1904, and they used a dipping machine system in 1905. The process as follows.

Suggestions and instructions for making records from mother moulds.

1. The regular dipping kettles are not used a nine gal capacity kettle on which is mounted two regular dipping machines is employed.
2. Another kettle of about ten gallon capacity is placed along side the larger kettle for the purpose of replenishing the wax in the large kettle keeping just enough wax in the small kettle for immediate use.
3. Regular moulded record wax is used with following exception, lamp black should be omitted and 2% more carnauba wax added, we are using the carnauba formula, not the ebonite formula.
4. The temperature of the wax in the dipping kettle should be kept about " or as near that temperature as possible before starting to mold, morning and noon the temp should be raised to about 300 and and well stirred so as to break up and melt the conjealed wax bring the temp down before starting to mold records. The wax in the other kettle should be at about 310.
5. This is supplied with 14 special molds and 40 regular jackets assembled and to be heated to a temperature of 100 degrees F this temperature of course should be absolutely fixed and is governed by working conditions as will be supplanted.

6. The molds after being place in the dipping machines should be dipped the same as the regular commercial records the time of immersion being about two minutes this includes the lowering of the mold and immersion in the wax.

7. While the first mold is dipped and taken from the dipping machine it is laid on a V block and another mold placed in the dipping machine and lowered in the wax, then if two minutes has elapsed the second dipping machine the mold taken from it and placed on the table as another mold placed in the machine is lowered in the wax there should be a mold waiting on the table to the trimmed at all times.
8. The mold resting on the V block is now taken out of the jacket and trimmed one to one quarter minutes should elapse from the time it is taken from the dipping machine until it is taken out of the jacket and trimmed, the jacket should be placed on the table until eight or ten accumulate and then taken out of the jacket and placed in a tank of water which has a temperature of 88-90 degrees F so as to reduce the temperature of the jacket to the temperature required for extracting as mentioned hereafter. Eight to ten jackets may be taken from the cooling tank at a time and wiped dry placing them handy for the man extracting. After the mold is trimmed it is reamed immediately with a single knife only to reaming machine reaming the record with a solid bore instead of a ribbed bore. We are using a small hand reaming machine and with one knife, thus the reaming is made with one operation.
10. After being reamed they are placed in cooling jackets which should have temperatures of 88-90 degrees F.
11. After being placed in the cooling jackets they are put on the extracting machine and left until its own gravity forces it out, in other words this statement is not absolutely true, but it must not be forced in other words, they are left on the extracting machine a little longer than is with the commercial records, so as to avoid scratching the record. Time consumed in trimming, reaming and extracting label records, about thirteen minutes (the word is cut off it could be 3 or 13.), one minute longer for molds without the label. The water that circulates thorough the cores should be about 104 degrees.
12. after extracting, the records should be placed on the metal cores being sure they both are on the board holding cores. The cores should be warm, having a temperature of about 95-100 F they should be on the cores about two hours before knocking off.

13. The molds and jackets as left by the extracting machine including the interval before again being placed in the dipping machine of the proper temperature for again dipping. There are from 4-6 molds on the side, ahead of a dipper most of the time. Times consumed for times mold is dipped until it is dipped again is about fifteen minutes for label molds, without the label it takes about one minute longer 16 minutes to extract the record from the plain mold.

14. When the records appear streaked or dirty after extracting the molds should be washed in benzole and dried and polished with a soft chamois and then place the mold in a heated jacket. for a few minutes to heat the mold before placing it in the jacket that was used to extract the record from it on the extracting machine The above instructions cover the grounds on the general way . After having been left on the core two hours, they are then knocked off and go through an eye inspection also for out of round and off gauge. The records that stood this inspection are left to stand until the following day, when the records are given a similar inspection so well as a thread tests, this is secure. The thread should gauge at between the following limits at the different temperatures as follows
at
70 degrees ¾ thread short ½ thread long
80 degrees 1/.2 thread short and ¾ long
90 degrees ¼ thread short and 1" long

The records should be kept over night in a place at an even temperature.

We are using entirely new wax for making these records although it is not necessary as we have taken the same wax in the kettle at the end of the week and filtered it though a muslin filter and used it the following week, not noticing any changes in the making of the records other than the color which is much darker. The scrap wax such as trimmings and defective records are put back in the small melting kettle and melted for supplying the larger kettle the same as in our regular mold process. By mixing lamp black with this wax it may be used for molding our regular records.

Oct 4th 1904 D.A. Dodd.

[Lenoirstreetguy]

This is fascinating. The American Machinist article was reprinted in the Michigan Antique Phonograph Society journal a while back. It partially answers the question as to why they held on to the wax record as long as they did: as a semiautomatic process the per unit cost would be quite low. In the Blue Amberol system it took two men to run the presses: as I understand it the mould for each record had to be hand operated meaning the labour cost per unit would be higher. Still didn't justify hanging on the wax process of course. They just couldn't set aside their pique over being " robbed" of the rights to the celluloid patents by the courts. They couldn't seem to just swallow their pride and essentially do what they eventually had to do did in 1911: buy the patent rights from the competition.

Jim