Audiodisc Yellow vs Blue vs Red label

[EposLab]

Hello there!
Since i fell in this"lathe trap" i use my RekOKut Master Pro lathe for embossing and i am very happy about the reaults, BUT i am always looking to use my lathe in the way it was meant to be used..in other words i like to cut 16" acetates using sapphire stylus!
All this time i look around the net and find different types of Audiodiscs (by Audio Devices Inc) which i believe they were made around the same time of my lathe!
So i wonder , sice these acetates are old enough, are they still in usable condition and also what are the differences between Yellow , Blue and Red labels??

Thank you in advance!
Tasos
Epos Laboratory

[emorritt]

Red label audiodiscs were the "professional quality" line with the fewest imperfections. Blue label discs were intended for the home recording market, with the coating being on a thin substrate. Reds were thicker. Yellow label were also intended for home recording, but the product was offered with either an aluminum or glass base, making these more rigid than the blues. The company also produced "master" discs, which were intended for industrial use. I have two copies of different editions of the source in my collection.

Audio Devices, I. (1945). How to make good recordings. New York: Audio Devices, Inc..

[EposLab]

Thats nice to hear! Thanks for the info!
The book you refer is available for online view here:
https://babel.hathitrust.org/cgi/pt?id=mdp.39015007927877&view=1up&seq=1

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[piaptk]

Thats nice to hear! Thanks for the info!
The book you refer is available for online view here:
https://babel.hathitrust.org/cgi/pt?id=mdp.39015007927877&view=1up&seq=1

This book is the Cutting Newbie Holy Grail. I own four copies!

[EposLab]

This book is the Cutting Newbie Holy Grail. I own four copies!

Indeed its easy to read 'n' understand!
Let me know if you're willing to sell a copy!

[EposLab]

Well , i manage to get both Yellow and Red label 16" Audiodiscs in NOS condition!
They will arrive soon and hope they're still in usable condition!

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[EposLab]

So few days back and today both packages arrived at my lab! As seen on previous pictures , the original packing was not in real good shape and i was almost sure that all the discs would be broken already.. Happily for me that didn't happened and only few disks were scratched on the one side and mostly close to the edge of the disc.
What i really noticed , while opening the boxes, was a intense smell like when you open an old wine barrel..
While in inspecting every disc i noticed that they all had a kind of discolouration, from black (very dark red) to cherry red and in-between there was some oil line on surface (is this the castor oil?) .

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Since i have 0 expiriecce with lacquer discs i would like to know if there is something i have to take care of . I know these are very flammable and i gave a try already just be sure!

[emorritt]

Lacquer discs won't support combustion, but the chip cut from them is dangerous if sparks or flame come in contact. Chip jars on recording lathes originally had a small amount of water in the bottom to keep the chip from igniting. The discs you have are most likely too dry to cut, due to their age. That doesn't mean they won't work, but they may be noisy and will wear out your cutting stylus more quickly than fresh lacquers. If there is a white powdery substance on the disc surface, this is palmitic acid leaching from the "mix" the disc is coated with. You can clean this off with a solution of regular household ammonia and a terry cloth towel. I couldn't see in the photo what you think is an oily substance; I'm not sure what that might be without a better look at it. Hope this helps.

[EposLab]

@emorritt thatnk for the info! On first 2 pics you can see the colour change on the surface of the discs. On 3rd you can see the an oily line on the surface of the disc. This oily line us just on the "boarder" between the darker and lighter surface!
I also believe they will be more dry but i want them for my own experiment purposes and not any professional use , my knowledge and my lathe are not professional anyway

[emorritt]

OK that seems to be a chemical reaction; if they did come from Louisiana, it's possible heat and moisture affected the surface of the disc. Yes, there's nothing wrong with cutting old lacquer that's dried; just not too dry, otherwise it will flake away leaving a noisy or even rough looking groove. I've used dime-store lacquers for demonstrations from the 40s or 50s that cut just fine. Another interesting thing is the palmitic acid issue. I have a lot of old lacquers from the late 1930s through those made by Apollo up through the fire. For some reason, a lot of the old discs don't have the palmitic acid problem. I have some Apollo discs that are roughly 10 years old that are covered in the residue. Not sure why this is.

[EposLab]

What i got i think they are from late 50's cause on sleeve it says "makers of Audiotape"! I will look for a sapphire cutting stylus just to try out. First with no heat coils as i have no pump but I am really looking forward to make a cut just like the 50's