----- Original Message -----
From: "Malcolm Rockwell" <[log in to unmask]>
> Yes. Most common method is to put the record in between 2 sheets of flat
> glass, put the "sandwich" in direct sunlight until the shellac softens
> enough to unwarp the disc, remove sandwich from sunlight and let cool 2 or
> 3 hours. Voila, a flat disc.
> There are exceptions to this method. It doesn't work on Columbia laminates
> or "acetate" (lacquer) discs, either.
> Ovens have been used, as opposed to sunlight, but not your home oven. And
> not a microwave.
> The softening temp usually cited is 125 degrees Fahrenheit and most ovens
> will not go that low and have any temperature control or reliability.
> I'm sure others on list will chime in about all this.
> Note that Vinyl (LP's and 45's) CANNOT be thus "de-warped! When
vinyl discs are heated to the point of warping, the plastic itself actually
expands...and the thus "extra" material is absorbed by the warping!
Steven C. Barr