[78-L] Layers of lacquer?

[Michael Biel]

  On 9/17/2010 10:21 AM, Thatcher Graham wrote:
> I have definitely seen acetates whose lacquer was laid down in multiple
> layers.  When the label falls or peels off  it sometimes reveasl an area
> of irregular coverage with plainly visible layers.
>
>

Of course they were not acetate.  The material was Cellulose Nitrate, so 
if you don't call them lacquers, they would have been called "Nitrates".

The discs described above were dipped.  The irregular edge on the blank 
center comes from the rubber separators between the discs as they were 
put on a long rod for dipping into the vat of lacquer.  Most of the home 
grade discs were made this way with the center part covered by a paper 
label.  This also was the second technique used by Presto in the 1937-39 
era when they painted a green "seal" on the center.  I believe these 
were made in their first New Jersey factory under the Pulaski Skyway.

The first Presto discs in 1934, and also the Cecil Watts Marguerite 
Sound Studios (MSS) discs, were sprayed.  Watts and his wife did them by 
hand, and the first Prestos were also done by hand but that might have 
been automated after a while.  Presto's Morris Gruber's brother died 
when he lit a cigarette right outside the spraying room and he inhaled 
the burning gasses which resulted.  These discs were made in their 
Brooklyn location.

Presto's third and longest-standing technique was done in their Route 4 
Paramus New Jersey factory.  The discs were on a conveyor belt and 
passed thru a curtain of falling lacquer which were controlled by 
knifeblades.  The discs would dry while on the belt which ran the length 
of the long building.  The higher grade discs would get more layers of 
lacquer.  After a curing period of a day or days, the other side would 
be coated.

AudioDiscs were made by applying a sheet of solidified lacquer to the 
aluminum base.  It is why these discs are more likely to flake off in 
large chunks.

As was mentioned by dl, some of the mastering grade discs would be sold 
with a preferred side.  This came in the quality control section.  They 
weren't designed to be single sided, it just enabled them to sell you at 
a discount a disc that had a slight flaw in only one of the sides, 
rather than trashing the disc or downgrading it to the lower price 
grade.  In general, Presto and the others used only one grade of 
lacquer, and the price was based on the thickness of the aluminum base, 
the extra thickness of more lacquer layers, and quality control 
decisions.  For a single playback you could get away with a lower grade 
than you would use for mastering.  If you were mastering you would only 
be using one side anyway, and you would never flip a disc over if one 
side had been on the turntable surface.

During the war there were companies which would take your old aluminum 
discs and strip them and recoat them. Some of these coated only one 
side.  Just like Hit of the Week which was coated on only one side, this 
would potentially compromise the flatness of the disc although I don't 
recall seeing any problems with these.  Some of the European discs in 
the 1933-35 era had a painted second side, and you had to be VERY 
careful not to confuse the dark blue paint for the coating.  This was 
done on some of the discs that were coated with gelatin instead of 
lacquer, but it might also be on some of the MSS discs.

Mike Biel  mbiel at mbiel.com

> Rodger Holtin wrote:
>> Layers of lacquer?
>>
>> I was asked this morning how the aluminum-lacquer ("acetate") records were made, and I realized that I really didn’t know.  Specifically, were the discs dipped in a vat or what?  I used to think so, but I’ve seen a few that had a straight edge along the outer rim that indicated to me that maybe a ribbon of lacquer was aid on the discs.  And, I suppose, it may have varied from Presto to Wilcox etc.  I’m sure somebody (paging Dr Biel) out there knows.  It may even have been discussed/answered here before, but not under a meaningful subject title that could be searched, of course.
>>
>> Rodger
>>
>> For Best Results use Victor Needles.
>>
>>