From mboxrd@z Thu Jan  1 00:00:00 1970
From: wb@freebie.xs4all.nl (Wilko Bulte)
Date: Wed, 31 Oct 2007 19:09:11 +0100
Subject: [TUHS] Recovering flaky CDs
In-Reply-To: <20071031164736.GB22786@freaknet.org>
References: <20071031162500.832803AA648@ws5-8.us4.outblaze.com>
	<20071031164736.GB22786@freaknet.org>
Message-ID: <20071031180911.GA25151@freebie.xs4all.nl>

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.

Wilko