[78-L] dewarping shellac, was AFRS

[David Lennick]

I once bought 6 store-stock party records on eBay and they were all dished to 
the point of being unplayable. Graham Newton flattened all of them successfully 
and while I didn't play them all, I didn't notice anything odd in the roundness 
department.

dl

On 2/12/2011 9:48 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!
>>
>> Steven C. Barr