The Talking Machine Forum — For All Antique Phonographs & Recordings

I'm wondering whether the plate glass / sunlight technique might also work to remedy edge curl on Diamond Discs? I've done a brief experiment (on an unplayable disc, natch) with a hot knife; and it seems to have a slight effect...

Bill

I have a feeling exposing dd's to sunlight would only make the problem worse, though I could be wrong.
I doubt there's anything that could fix the problem on a long term basis.

I have seen edge curl mostly on the older black etched label records. Edison disks are not made from shellac like the 78's; rather, the laminated surface is an Edison equivalent of Bakelite and therefore eating it may not do it any good.

VintageTechnologies wrote:I have seen edge curl mostly on the older black etched label records. Edison disks are not made from shellac like the 78's; rather, the laminated surface is an Edison equivalent of Bakelite and therefore eating it may not do it any good.

True, these are late 'transfer' discs. They were actually pressed on celluloid coated with Condensite varnish, which was then bonded to the core. Since celluloid is a thermoplastic, I wondered whether the proper application of heat might soften this enough to enable the edge to be pressed back down.

It's likely that celluloid softens at a higher temperature than shellac; and of course the Condensite may not soften at all....

-Bill