[TUHS] Recovering flaky CDs

[jpetts@operamail.com (James Petts)]

> ----- Original Message -----
> From: "Wilko Bulte" <wb at freebie.xs4all.nl>
> To: asbesto <asbesto at freaknet.org>
> Subject: Re: [TUHS] Recovering flaky CDs
> Date: Wed, 31 Oct 2007 19:09:11 +0100
> 
> 
> Quoting asbesto, who wrote on Wed, Oct 31, 2007 at 05:47:36PM +0100 ..
> > Wed, Oct 31, 2007 at 08:25:00AM -0800, James Petts wrote:
> >
> > > > > > Is there anybody on this list who knows a way of 
> > recovering flaky CDs?
> > > > > Easiest first step is try using different kinds of 
> > CD/CD-R/DVD-R drives.
> > > > > I have found some 'unreadable' CDs could be read using a DVD drive.
> > > > I remember a very old SONY cd-rom reader capable of reading very
> > > > damaged cd! It was the SONY CDU-33A, it has his
> > > > own controller, so was not an IDE or SCSI drive. But it can be
> > > Those CD Doctor "cleaners" (they actually do a minor
> > > resurfacing of the disc) have rescued several discs
> > > for me.
> >
> > A great problem I had some time ago was a sort of oxydation of the
> > cd material; this seem to happen using very bad cd brands. i had
> 
> Note that the reflecting layer in factory produced CDs is aluminium.
> A thin layer of lacquer is protecting the reflector.
> 
> As an interesting eye opening experiment I dumped one of these AOL promo CDs
> we used to be bombarded with in a bowl of lukewarm water.  Plain water, 25
> degrC. Within a day the aluminium layer had holes in it the size of dimes.
> Apparantly the protective lacquer was very substandard.
> 
> El-cheapo CDR can have similar characteristics.

And it is the top side (label side) of the CD that is most
fragile, not the reading side. There is about 0.5 mm of
plastic that can take some pretty fearsome scratches and
still be readable, or at least resurfaceable (is that a
word?).