Check this out. A recording blank made of glass. This fellow seems to think that the grooves are cut into the glass. Can anyone shed some light on this?
http://www.recordcollectorsguild.org/index.php?name=PNphpBB2&file=viewtopic&p=546921#546921
Recording Blanks Made of Glass
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Aussie0zborn
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Recording Blanks Made of Glass
Last edited by Aussie0zborn on Tue Feb 14, 2012 12:21 am, edited 1 time in total.
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Perisphere
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Aussie0zborn
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Angus McCarthy
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A glass base was used during WWII due to the aluminum shortage. Sometimes a cardboard center was used to make the stress point of the drive pin hole less fragile. I think the lacquer actually held it in place.
As for the clear coating the fiber core home recording discs had a clear coating, so it's not unheard of.
As for the clear coating the fiber core home recording discs had a clear coating, so it's not unheard of.
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Aussie0zborn
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Beisdes glass masters another thing that was used during wwii was iron stampers They where really into it due to shortage of Nickel chromium as well as copper
It was the record industry that really did all the work on elctroforming/plating Iron which held promise for lots of other items but once nickel became available again iron was abandoned
Cheers
It was the record industry that really did all the work on elctroforming/plating Iron which held promise for lots of other items but once nickel became available again iron was abandoned
Cheers
Chris
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Jesus H Chrysler
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Hello,
glass disc as a base material was caused by war shortages of aluminum. However, glass was used even post-war, and Audio Devices had a whole line about which they proved that it had much less rumble than the aluminum discs. It was simply impossible to polish aluminum to that degree, and any unevennesses in the base material would show in the top part of the lacquer layer. Now, with feedback, the mechanical impedance of the cutter would be much higher, and small variations in the lacquer layer would not mean as much. With the wet processes involved I very much doubt that glass-base lacquers were actually used for mastering - the fiberboard insert in the center would not take kindly to it. But I have no positive knowledge about that. However, I do know that it was cellulose nitrate that was the main constituent in lacquers, not cellulose acetate. I have never seen a glass-base lacquer that was not colored, and the only yellowish transparent ones were usually of gelatin that could never be used in a wet process.
Glass discs are good candidates for coating your own experimental lacquers.
Transparency is everything!
glass disc as a base material was caused by war shortages of aluminum. However, glass was used even post-war, and Audio Devices had a whole line about which they proved that it had much less rumble than the aluminum discs. It was simply impossible to polish aluminum to that degree, and any unevennesses in the base material would show in the top part of the lacquer layer. Now, with feedback, the mechanical impedance of the cutter would be much higher, and small variations in the lacquer layer would not mean as much. With the wet processes involved I very much doubt that glass-base lacquers were actually used for mastering - the fiberboard insert in the center would not take kindly to it. But I have no positive knowledge about that. However, I do know that it was cellulose nitrate that was the main constituent in lacquers, not cellulose acetate. I have never seen a glass-base lacquer that was not colored, and the only yellowish transparent ones were usually of gelatin that could never be used in a wet process.
Glass discs are good candidates for coating your own experimental lacquers.
Transparency is everything!
Glass masters
I picked up a box of 12 inch blanks on Ebay recently and the wooden crate they came in was marked "Fragile - Glass". The lacquer is black, though so I'm not sure if they are really glass. I don't want to try breaking one to find out! They do seem to be heavier than the aluminum ones I'm familiar with. I'll have to try cutting one and see what happens.