A number of CDs of mine that had been stored for about a year showed crazy patterns on them where the aluminum substrate had just ... disappeared. The erosion was in the pattern of crazy trails, not unlike the kind worms leave just under the surface of tree bark (all jiggly and zig-zaggy like). There were no surface scratches evident, this was purely the aluminum under the surface of the CD.

My questions are these: Has anyone ever seen this before? Is there a whitepaper, or some other pointy-headed scientific-type writing on this that I can read? More to the point, how can I prevent this?

how can I prevent this?

You can't. Some cd's are more prone to flaking than others.

It's that unstable digital media.

are they cd-rs or actual 'pressed' cds?

Redline wrote:

how can I prevent this?

You can't. Some cd's are more prone to flaking than others.

It's that unstable digital media.

It's called "flaking"? Hmm. I didn't see where the aluminum went ... it just vanished, like magic. Black magic. Black magic that sucks the music out of my goddamned CDs. I'm going to google "CD flaking" now.

But anyone with any technical jive should feel free to weigh in.

And yeah, I know, vinyl doesn't have this problem.

same wrote:are they cd-rs or actual 'pressed' cds?

Factory CDs.

Up.

Attaching myself to thread. Going to Web Crawler: "flaking". I'll post links
if anything great pops up.

it may be called "flaking" but it is oxidation - deterioration of the aluminum foil layer based on bad manufacturing techniques. there is either something out of whack with the plastic composition, or there was some moisture trapped when the CD was made, or a tiny flaw in the sandwich that allowed moisture to penetrate. I have a few older CDs that have big dime sized holes in the AL from this. Others, as old or older are just fine.

I've always heard it called "CD rot". I just did a quick Google using that phrase and a bunch of stuff popped up. Good luck.

it may be called "flaking" but it is oxidation

That's just what I call it - "Dag, that disk is flaky". I don't know what the industry standard term is for it...

Probably "oxidation", hee heeee.

The most notorious source are a lot of PDO manufactured CDs from the mid to late 80s. Many of those CDs were repressed correctly later, but many were left out of print due to lack of demand... so back those latter ones up immediately.