I have handled a few thousand glass-base 16" discs in my life. Currently,
there are about a thousand of these in my garage.
They are extremely fragile. I have seen them break merely by being picked up
carefully. Once when doing research in the bowels of the LOC, a disc
shattered in the hands of the person assisting me. He was very experienced
with such discs (the eponymous Jim Smart), he did everything correctly, but
it shattered nonetheless.
My advice is to treat them as if they were explosive. Carry only one at a
time. Try to carry it on a flat sacrificial aluminum base 16" disc. Never
leave it unsupported. Avoid any situation where it might flex, because it
doesn't want to flex; it wants to break. If moving a box of them, make sure
that the box is reasonably rigid and that the contents are protected from
external forces and that the contents cannot flex.
Although glass has a smoother surface than metal, World War II was the
reason for its widespread use. Aluminum was declared a war priority item and
was unobtainable for civilian use. In addition, there were large "drives" to
solicit donations of aluminum from the public. Vast numbers of aluminum 16"
disks were donated to these drives (as well as pots and pans), thus
destroying a large part of our audio legacy. Then there were services that
would recoat used aluminum discs with fresh lacquer for reuse, again
destroying more of our audio history. It's a miracle that any survived; it
also explains why so little of pre-war transcriptions exist. The majority of
16" lacquers that I have seen are from 1940 though the mid-1950s. The ones
from 1934 through 1939 are relatively scarce. Unfortunately, none of "us"
were around and in a position to do anything about it back then! Libraries
didn't archive such things.
Lacquer transcriptions were made for various purposes, such as syndication,
delayed broadcast, verification of commercials that were broadcast, etc. In
addition, there was a law in America that any shortwave broadcast from
America had to be recorded. Millions were made over the years, but sadly,
history has not treated them well. Those that survive are slowly being eaten
by palmitic acid. It's a lugubrious tale.
From: Association for Recorded Sound Discussion List
[mailto:[log in to unmask]] On Behalf Of George Brock-Nannestad
Sent: Monday, May 17, 2010 9:51 AM
To: [log in to unmask]
Subject: Re: [ARSCLIST] Glass Records
From: Patent Tactics, George Brock-Nannestad
----- glass was actually preferred over aluminum because of the much greater
smoothness, i.e. less roughness, as the cut was more silent. The lacquer
layer is very thin and it follows every unevenness. Possibly adhesion would
have improved, but the usefulness of the result for sound recording would be
----- I should note that I have only once handled a 16" glass lacquer disc,
and here a 4" pile would be exceedingly heavy. And here you will have a real
quandary, because one disc is fragile when it gets this large, and you
really need to move a small pile at any one time, something like at least 10
if you intend to carry them by two hands.
----- just for the record I should also mention that there are indeed true
acetates around, but they were designed for the home recording market and
their great selling point was that the thread cut out was not inflammable.
I would chime in on a request for more information before we provide more