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Rocky Mountain Traders of London claims a magic mix for repairing damaged CDs
and DVDs (GB 2343288). Digital discs are pressed from polycarbonate, which
protects the “pits” that represent the data. Scratches in the polycarbonate
surface don’t damage the pits, but the scratch upsets the laser and makes discs
stick or skip. The patent claims a two-stage cure. First, the disc is rubbed
from the centre out with a mix of wax, turpentine and emulsifier. This fills the
scratch. Then, when the mixture has dried, a silicone sealing solution is rubbed
on. This forms a clear skin that stops the laser jumping.