[78-L] dewarping shellac, was AFRS

[Malcolm Rockwell]

Try this. You'll need a nice flat piece of wood, like a chopping block. 
Place the warm, relaxed record on the block. Wearing either a glove 
(cotton, white type) or using your bare hand rub the disc with an even, 
slight downward pressure in a circular motion, with the groove, until it 
begins to cool. It will cool fairly quickly due to the temperature of 
the wood. Then leave it alone for a few minutes to allow it to cool 
completely. Voila... a flat record. I've never had a record go out of 
round using this method.
That said, how you warm up a standard shellac record is a whole other 
matter. None of this will work on Edison DDs or on laminated Columbias 
or OKehs. It has to be one piece shellac.
Malcolm

*******

On 2/12/2011 4:48 AM, neechevoneeznayou at gmail.com wrote:
> I've never had much success dewarping shellac. Yes it can be warmed
> gently and pressed into a flat condition, but somehow the thing seems
> afterward to be out of round.
>
> Anyone else ever encountered this?
>
> joe salerno
>
> On 2/11/2011 9:45 PM, Steven C. Barr wrote:
>> From:<neechevoneeznayou at gmail.com>
>>> OK, so if vinyl is warmed sufficiently and put under some pressure, it
>>> can be forced to change shape, which is how vinyl records are made in
>>> the press as we all know. Same for shellac, altho lower temps will warp
>>> shellac. I assume a record store at an angle or with something on top of
>>> and below could do the same over time, be forced out of a flat
>>> condition. If these transcription records were packed tightly in boxes,
>>> perhaps this will not have occurred.
>>> That would explain why I have seen so little warping in my vinyl
>>> collection, excluding those records which came factory pre-warped.
>>>
>> The OTHER difference is that shellac records exposed to high
>> temeratures becdome flexible...and retain their new shape when
>> cooled. Repairing this requires only that the records be reheated
>> to the point of flexibility and manually be bent into "flatness"...!
>>
>> OTOH, vinyl records when "over" heated will actually expand
>> physically...creating a "warp" when the newly expanded vinyl.
>> with "no place to go," forces the record to "warp" and thus
>> accomodate the expanded vinyl!
>>