Just a small note, I am a he not a she. :-)  My name is pronounced like 
"shy". 8-)

Michael Biel wrote:
> -------- Original Message --------
> Subject: Re: [ARSCLIST] Quick ID - shellac, instantaneous, vinyl
> From: Shai Drori <[log in to unmask]>
> Date: Thu, November 19, 2009 1:10 pm
> To: [log in to unmask]
>
> I never thought of this. It's sort of automatic to me and I guess to 
> everyone else. The look and feel totally different, that I never spent 
> a second thinking about it.
>
> Having handled records for over sixty years, this is generally my
> reaction also, except that I have been a teacher and in addition to what
> I told my classes about the common items, I have been teaching my
> daughter about all of the various media we come across.  Whenever we go
> thru records and I spot something unusual I always point it out to her. 
> But it comes as second nature to me, even by feel.  I usually can
> immediately tell if a lacquer disc is aluminum, glass, steel, or fibre
> instantly.  Glass can fool many people but I somehow just know if it is
> glass.  They immediately feel different to me, just as Shai also seemed
> to know that the discs she handled were glass.  The visual clues include
> the edges, the center hole, the weight, as well as, of course, the ring,
> the translucency, etc.  There also is a difference in how the light
> reflects in addition to transmission thru the disc.  But you can't teach
> it -- you learn it by doing.  
>
> There are two variations of glass beyond the normal, by the way.  The
> first Presto glass was twice as thick and had a center hole grommet. 
> They seem indistructable but they aren't.  When I moved from Missouri to
> NJ in 1974 all the glass survived EXCEPT the thick Presto I had.  But it
> was a common FDR speech.  AudioDiscs had a fibre center about 2 inches
> in diameter.  So the spindle and driving holes are not in the glass but
> in that fibre disc.  It is held in place by the lacquer and the paper
> labels.  It can fall out, but all you have to do is replace it!  
>
> Mike Biel  [log in to unmask]  
>  
>
>  Vinyl is light flexible has a certain shine 
> to it and almost no sound when you handle it. Shellac has this sound to 
> it when you handle it that sounds brittle, sort of like a "don't @#$^ 
> with me". And instantaneous are very heavy compared to the others of the
>
> same size. Of course there are exceptions to the rule but over time you 
> sort of just know.
> The last time I was puzzled by a record that felt "wrong" was a few 
> years back when I got a shipment of glass records. During the War 
> aluminum was gone to the army and different substances were used for the
>
> base, glass among them. Never been more scared than handling those 
> records and that includes nitrate stuff. The up side was that they were 
> ruler flat and played on the emt like a dream, great sound.
> m2c
> shai
>
> Tracy Popp wrote:
>   
>> Hello All,
>>
>> I have a question on visual identification of, and differentiation among
>> shellac, instantaneous and vinyl grooved disks. Are there quick visual and
>> non-destructive methods of determining the type of disk?
>>
>> I am aware that most instantaneous have three "spindle" holes in the center,
>> and one can generally determine that a disk is an instantaneous based on the
>> core material (if one can see the core material.) Any other suggested
>> methods of quick ID and differentiation - barring cracking the edge of the
>> disk to see the material composition? Is gently tapping the disk surface,
>> and listening for aural cues about material density an useful practice?
>>
>> Thanks for your assistance!
>>
>> Best,
>> Tracy Popp
>> UIUC Graduate Student MLS
>>
>>
>>     
>
>