In the 80s/90s some CDs suffereed from what they called "rust" (due to it's brownish colour) appearing on the recorded side of the disc and was put down to a problem with the manufacture. This could be a similar manufacturing fault.
This is "CD rot". The medium is EOL due to age, decomposing material and moist and should have been backupped to a modern medium before this happened. One can replace lasers, mount low jitter clocks and swear CDs are the dogs bollocks: still the media die. Most practical is to be in time before that final moment. Just like all stuff there is a beginning and an end.
Except sausages, these have 2 ends.
Except sausages, these have 2 ends.
I've seen discs with genuine rot over the entire surface area (a boxed Deutsche Grammophon set from a library) where you could hold them to the light and literally read a newspaper through the mottled surface.
Maybe I've been extremely lucky with all mine but one thing I have always done is to clean them with spray polish (ordinary household silicone multipurpose surface/furniture polish) as soon as I got any new disc. Even after all these years and they all look in pristine condition.
Maybe I've been extremely lucky with all mine but one thing I have always done is to clean them with spray polish (ordinary household silicone multipurpose surface/furniture polish) as soon as I got any new disc. Even after all these years and they all look in pristine condition.
Looks like nanobots did it...
Seriously though, I believe that the aluminium reflective layer is open on the edge of the disc - would there be any merit to sealing it as a preventative measure?
Maybe the audiophiles' 'Green Pen' trick did something after all!
Seriously though, I believe that the aluminium reflective layer is open on the edge of the disc - would there be any merit to sealing it as a preventative measure?
Maybe the audiophiles' 'Green Pen' trick did something after all!
I remember this being predicted but never seen it before personally. Do you have just one CD like this?
I THINK I remember reading years ago that some bacteria or fungus can cause this, but my memory isn't very good.
Edit: just Googled it - there is plenty out there on fungus causing this problem.
Edit: just Googled it - there is plenty out there on fungus causing this problem.
🤣🤣🤣
Thanks Jean Paul
Disc rot is real.
I have several discs that have disc rot, all of them came from a collection that spent several years stored in a damp shed. I suspect improper storage may be a factor.
Manufacturing defects may account for many other failures. Here is an example. It looks like the orange silkscreen reacted with the top protective layer.
I have several discs that have disc rot, all of them came from a collection that spent several years stored in a damp shed. I suspect improper storage may be a factor.
Manufacturing defects may account for many other failures. Here is an example. It looks like the orange silkscreen reacted with the top protective layer.
Attachments
Great answers but... no one have found the hypothesis that these strange "nanobot-bites" are located on the sides and probably localized on the mecanical "impacts".
This is perhaps a small delamination and something have entered the "matrix"... chemical reduction ?
This is perhaps a small delamination and something have entered the "matrix"... chemical reduction ?
I believe it’s a reactant ingress that is destroying the aluminum layer, possibly caused by condensation cycles. The outer and inner edge are supposed to be sealed with a lacquer to protect the reflective layer, but it’s not always going to be consistently applied.
I had one CD-R disc with a different failure mode, a brown “rust” appearance near the edge. I see discs pressed in the 80’s - 90’s and none have signs of problems. I’ll have to do a deep search among my discs and see what I can find.
I had one CD-R disc with a different failure mode, a brown “rust” appearance near the edge. I see discs pressed in the 80’s - 90’s and none have signs of problems. I’ll have to do a deep search among my discs and see what I can find.
If it is on the sides it may be sweat from your fingers that reacted with some coating of the CD. Usualy you touch it like that and the final coating may be weak at the outer diameter.
I know this CD rot was a very important topic when the German government started to transfer data from paper and microfices to CD's. They store all the stupid sh''t they produce every day in nuclear safe bunkers. These government people have lost any touch to reality and think it is important for the generation after the nuclear catastrophy to know how the Bundestag voted about any senseless dispute. Yes, things like that and tax records are worth to be saved... when the whole planet is depopulated because Vladimir Putin did not get his personal will.
They found out that CD's should last more than 100 years if stored dry and used correctly. The color of the label did sometimes eat up the data layer on early mass CD production. This was when the CD got common and factories started to try cheaper components in production. Should be no problem any more.
I know this CD rot was a very important topic when the German government started to transfer data from paper and microfices to CD's. They store all the stupid sh''t they produce every day in nuclear safe bunkers. These government people have lost any touch to reality and think it is important for the generation after the nuclear catastrophy to know how the Bundestag voted about any senseless dispute. Yes, things like that and tax records are worth to be saved... when the whole planet is depopulated because Vladimir Putin did not get his personal will.
They found out that CD's should last more than 100 years if stored dry and used correctly. The color of the label did sometimes eat up the data layer on early mass CD production. This was when the CD got common and factories started to try cheaper components in production. Should be no problem any more.
The major problems seem to occur with PDO discs made in UK; which PDO admitted and even offered replacement discs. The shown PDO made in France might have used the same problematic lacquer.
As of about 10 years ago (when I last checked my collection) I had one affected disc, Manufactured 1988 in UK, can't remember the manufacturer. Large areas discolored, but still playing fine (back then).
As of about 10 years ago (when I last checked my collection) I had one affected disc, Manufactured 1988 in UK, can't remember the manufacturer. Large areas discolored, but still playing fine (back then).
PDO?
I have seen only one CD rot disc: a L'Oiseau Lyre (Decca) set of Christopher Hogwood's Messiah. Discoloration/corrosion of the aluminum was clearly visible. Stored in unconditioned space in Honolulu HI at a friends condo. He gave me the two-disc set; the other disc was still playable. It is my backup for my own Hogwood CD set.
I am skeptical that there is a safe way of applying a protective layer to either the edge or the surface of the disc, without the solvent of the protection itself instigating corrosion or otherwise upsetting weight distribution of readability of the disc.
Bottom line: I store all my CDs in conditioned space, and I am not going to waste time (at age 69) ripping them for back-up.
I have seen only one CD rot disc: a L'Oiseau Lyre (Decca) set of Christopher Hogwood's Messiah. Discoloration/corrosion of the aluminum was clearly visible. Stored in unconditioned space in Honolulu HI at a friends condo. He gave me the two-disc set; the other disc was still playable. It is my backup for my own Hogwood CD set.
I am skeptical that there is a safe way of applying a protective layer to either the edge or the surface of the disc, without the solvent of the protection itself instigating corrosion or otherwise upsetting weight distribution of readability of the disc.
Bottom line: I store all my CDs in conditioned space, and I am not going to waste time (at age 69) ripping them for back-up.
Yes, a European thing, similar to biodegradable wire insulation and other plastics and rubber issues since the 80's.