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Ambient temperature and playing records
http://forum.talkingmachine.info/viewtopic.php?f=3&t=31797
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Author:  CharliePhono [ Tue Aug 29, 2017 4:46 pm ]
Post subject:  Ambient temperature and playing records

I'd like others to weigh in on something new to me. In discussion with another forum member, it was proposed that it might be harmful to play our 78s on original equipment in temperatures around 80-85 degrees. This was news to me, but I can see, in theory, where it might be detrimental inasmuch as the member postulated there is softening of the record surface with concomitant undue wear - or at least that is how I understood it. We are having hellish heat here, with daytime temps well over 100, and inside my house has reached the 85-degree mark (no AC in solar-powered home, but multiple fans going). I have refrained from playing my machines, as much due to heat lethargy as anything else, but wondered if this was valid? What say ye all?

Author:  HisMastersVoice [ Tue Aug 29, 2017 4:57 pm ]
Post subject:  Re: Ambient temperature and playing records

I'm no scientist, but shellac has a melting point of around 175 degrees F. Certainly all of our records have been played in the heat of summer many times before air conditioning existed. Unless it's well over 100, I wouldn't worry about it too much. At those temps I wouldn't feel like cranking a phonograph anyway....

Author:  bfinan11 [ Tue Aug 29, 2017 5:00 pm ]
Post subject:  Re: Ambient temperature and playing records

I would be much more concerned about playing (wax) cylinders in the heat than 78s. I still don't think they would melt at such a low temperature, but it seems more plausible with a softer material.

Author:  donniej [ Tue Aug 29, 2017 5:30 pm ]
Post subject:  Re: Ambient temperature and playing records

In my testing with Victor batwings I found accelerated wear over 90*F. This was evident by "fluff" accumulating on a new, soft tone needle and subtle changes in the discs surface as the needle past over it.

I did this as part of the testing of my own 78 formula, for my reproductions. The discs were allowed to heat beyond the stated temp and when it had cooled to the desired temps, the disc was played on a VV-VIII with no. 2 reproducer. I then watched the disc and needle with a flashlight and a jewelers loupe (10x). Testing was done from 75 - 100*F, in 5* increments. I also did some testing regarding pliabilty, those temps were quite a bit higher, IIRC.

Author:  Orchorsol [ Tue Aug 29, 2017 5:41 pm ]
Post subject:  Re: Ambient temperature and playing records

Although shellac melts at around 80 to 100 degrees Celsius (sorry US friends, I have no grasp of Fahrenheit at all), in common with other thermoplastics it has at least one abrupt glass transition temperature at a lower value which seems to vary widely between different shellac grades and treatments. Below this temperature, as the term suggests, the material is much harder and hardness bears very little relationship to temperature; above, obviously softer.

I haven't seen any data relating to shellac records - it would be interesting to know where the typical glass transition temperature is for our purposes, and perhaps it varies between manufacturers and formulations. Sadly I no longer work with polymers, otherwise I could find out by testing! Does anyone else have access to a durometer and a good temperature controlled oven?

It does however seem possible that this could be towards the high end of typical ambient temperature ranges.

Author:  donniej [ Tue Aug 29, 2017 6:07 pm ]
Post subject:  Re: Ambient temperature and playing records

Orchorsol wrote:

Does anyone else have access to a durometer and a good temperature controlled oven?



Yes, and shellac is only about 12% of a typical 78. 78's also aren't as hard as many people think.

Author:  CharliePhono [ Tue Aug 29, 2017 6:19 pm ]
Post subject:  Re: Ambient temperature and playing records

HisMastersVoice wrote:
At those temps I wouldn't feel like cranking a phonograph anyway....


Well, there is that, B!

Author:  edisonphonoworks [ Tue Aug 29, 2017 7:34 pm ]
Post subject:  Re: Ambient temperature and playing records

I know I have a pittance of a collection of mundane machines, however I use it as an educational tool, and I am invited by fairs and exhibits during the summer and fall. I missed a threshing show this year, however tomorrow, I am setting up at the Tri-county fair in Mendota, IL (inside in a building), and at the Homer Harvest Days in Homer Glenn IL, on the weekend of the 10th. If you are doing outdoor events, it is a good idea, even in a shelter to protect your metallic soap cylinders, most Gold Moulded are fine, however try to keep a heavy blanket insulating them from direct sunlight, I have had cylinders spit from one side being cold and the other sunny, even at a modest 70F just sitting on a table, and they were not 10,000 series Gold Moulded or Wax Amberols, but normal 1905 era 8,000-9,000 series moulded records. I typically de-mold new blanks at about 200F, they are solid enough to retain their shape, however the main ingredient in cylinders, that makes up over 58% of the formula is stearic acid, and double pressed starts melting about 130-135 and triple from 135-140 F. Edison used a very rare stearic acid made by Mitchell and it was as close to triple pressed as stearic was at that time. In fact I just found a court case between two stearic companies in the 1870's that put much light on the manufacture of stearic acid.

Author:  BusyBeeCylinder [ Wed Aug 30, 2017 2:35 pm ]
Post subject:  Re: Ambient temperature and playing records

There were certainly a lot of formula's for "shellack" 78's...it would be interesting if anyone knows the formula's that Victor and Columbia used.

This formula is from US patent 1781711 filed in 1928, issued in 1930.

1. A composition of matter for use in making phonograph records and for other purposes, comprising a'filler, a shellac agglomerant by which the filler is bound together, and an azine base dye.

2. A composition of matter for use in making phonograph records and for other purposes, comprisinga filler, a shellac agglomerant by which the filler is bound together, and nigrosine base dye.

' 3. composition of graph records having substantially the following composition :-shellac 23%; ni rosine base dye 2% cotton-flock 4L%, and filler 70.25%. c

4. A composition of matter for use in making phonograph records consisting of shellac and a filler, and containing approximately 2% of nigrosinebase dye.

Author:  bfinan11 [ Wed Aug 30, 2017 3:57 pm ]
Post subject:  Re: Ambient temperature and playing records

Does anyone know what color these formulas would have been without the dyes? Assuming it wasn't black, when did black become the standard, and why?

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