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Posting-Version: version B 2.10.1 6/24/83; site rabbit.UUCP
Path: utzoo!linus!philabs!cmcl2!floyd!harpo!ulysses!allegra!alice!rabbit!ark
From: ark@rabbit.UUCP (Andrew Koenig)
Newsgroups: net.audio
Subject: Re: Flattening warped records
Message-ID: <2696@rabbit.UUCP>
Date: Wed, 11-Apr-84 10:24:40 EST
Article-I.D.: rabbit.2696
Posted: Wed Apr 11 10:24:40 1984
Date-Received: Fri, 13-Apr-84 01:21:39 EST
References: <53@tilt.UUCP>
Organization: AT&T Bell Laboratories, Murray Hill
Lines: 32

>>I bought a record last week that was so warped that my turntable
>>would not track it.  I therefore decided to try a technique I had
>>read about for unwarping the record.  Here it is:
>>
>>Obtain two pieces of 1/4 inch plate glass about 13 inches square.
>>You need glass that's heavy enough to keep the record completely flat.
>>
>>Put the record between the glass sheets and put the whole sandwich
>>in the oven.  Turn the oven up to 150 degrees for about 10 minutes,
>>then turn the oven off and open the door part way.  Let the glass and
>>the record cool to room temperature (about an hour).
>>
>>The record came out completely flat!  Score one for the good guys!

>Yeah, but did the grooves?  Think about it.  You're heating the
>vinyl to at best, just above the point where it begins to lose its
>rigidity, then subjecting it to pressure.  If it's enough to flatten
>the vinyl, think about what it must be doing to the grooves cut into
>the vinyl.  Consider also the width of a groove and how little change
>it takes to turn a cymbal clank into a thud.
>
>You might not hear it on YOUR system, but I wouldn't recommend this
>method to everyone else...

The object of the game is to heat up the vinyl just enough that it
will flow a tiny bit under pressure.  It is true that this might
affect the contours of the grooves somewhat, but I cannot imagine that
it could possibly have as much of an effect as playing the record,
which I understand heats up the vinyl a good deal.

I also expect that the record isn't completely cool when it comes out
of the mold.  We aren't talking about much heat here!