Something to remember CDR by...

[mmilovan]

http://www.cnn.com/2004/TECH/ptech/05/06/d...t.ap/index.html

(AP) -- Dan Koster was unpacking some of his more than 2,000 CDs after a move when he noticed something strange. Some of the discs, which he always took good care of, wouldn't play properly.

Koster, a Web and graphic designer for Queens University of Charlotte, North Carolina, took one that was skipping pretty badly and held it up to the light.

"I was kind of shocked to see a constellation of pinpricks, little points where the light was coming through the aluminum layer," he says.

His collection was suffering from "CD rot," a gradual deterioration of the data-carrying layer. It's not known for sure how common the blight is, but it's just one of a number of reasons that optical discs, including DVDs, may be a lot less long-lived than first thought.

"We were all told that CDs were well-nigh indestructible when they were introduced in the mid '80s," Koster says. "Companies used that in part to justify the higher price of CDs as well."

He went through his collection and found that 15 percent to 20 percent of the discs, most of which were produced in the '80s, were "rotted" to some extent.

The rotting can be due to poor manufacturing, according to Jerry Hartke, who runs Media Sciences Inc., a Marlborough, Massachusetts, laboratory that tests CDs.

The aluminum layer that reflects the light of the player's laser is separated from the CD label by a thin layer of lacquer. If the manufacturer applied the lacquer improperly, air can penetrate to oxidize the aluminum, eating it up much like iron rusts in air.

But in Hartke's view, it's more common that discs are rendered unreadable by poor handling by the owner.

"If people treat these discs rather harshly, or stack them, or allow them to rub against each other, this very fragile protective layer can be disturbed, allowing the atmosphere to interact with that aluminum," he says.

Part of the problem is that most people believe that it's the clear underside of the CD that is fragile, when in fact it's the side with the label. Scratches on the underside have to be fairly deep to cause skipping, while scratches on the top can easily penetrate to the aluminum layer. Even the pressure of a pen on the label side can dent the aluminum, rendering the CD unreadable.

Koster has taken to copying his CDs on his computer to extend the life of the recordings. Unfortunately, it's not easy to figure out how long those recordable CDs will work.

Fred Byers, an information technology specialist at the National Institute of Standards and Technology, has looked at writeable CDs on behalf of government agencies, including the Library of Congress, that need to know how long their discs will last.

Manufacturers cite lifespans up to 100 years, but without a standardized test, it's very hard to evaluate their claims, Byers says. The worst part is that manufacturers frequently change the materials and manufacturing methods without notifying users.

"When you go to a store and buy a DVD-R, and this goes for CD-R as well, you really don't know what you're getting," he says. "If you buy a particular brand of disc, and then get the same disc and brand six months later, it can be very different."

This renders the frequently heard advice to buy name-brand discs for maximum longevity fairly moot, he says.

DVDs are a bit tougher than CDs in the sense that the data layer (or layers -- some discs have two) is sandwiched in the middle of the disc between two layers of plastic. But this structure causes problems of its own, especially in early DVDs. The glue that holds the layers together can lose its grip, making the disc unreadable at least in parts.

Users that bend a DVD to remove it from a hard-gripping case are practically begging for this problem, because flexing the disc puts strain on the glue.

Rewriteable CDs and DVDs, as opposed to write-once discs, should not be used for long-term storage because they contain a heat-sensitive layer that decays much faster than the metal layers of other discs.

For maximum longevity, discs should be stored vertically and only be handled by the edges. Don't stick labels on them, and in the case of write-once CDs, don't write on them with anything but soft water-based or alcohol-based markers.

Also, like wine, discs should be stored in a cool, dry place. Koster's friend Mark Irons, of Corvallis, Ore., stored his CD collection in a cabin heated by a wood-burning stove. The temperature would range between 40 degrees and 70 degrees in the space of a few hours. Now, the data layer of some of his CDs looks as if it's being eaten from the outside.

Irons is still pretty happy with CD technology, since it beats vinyl LPs and tape for longevity. Now that he's moved his discs to an apartment with a more stable temperature, he's noticed that the decay has slowed.

"I'm hoping they'll hold out till that next medium gets popular, and everyone gets to buy everything over again," he says.

[Brandon Burke]

I was just going to post this article. Funny that no one is commenting, especially since I got such a hard time a few months ago for suggesting that CDs indeed deteriorate over time... B)

[rockefeller center]

especially since I got such a hard time a few months ago for suggesting that CDs indeed deteriorate over time... B)

I don't think anybody argued that.

[mikeweil]

Every music vanishes into space ..... some just takes a little longer.

[wesbed]

especially since I got such a hard time a few months ago for suggesting that CDs indeed deteriorate over time...    B)

I don't think anybody argued that.

I'm not certain anybody argued it either. I intend no diss at Brandon with today's post.

However, here is my post, from early March, to agree with Brandon's point that CDs don't last forever. I have an Ella CD that used to be a normal CD. But, is now clear. >link<

Edited May 11, 2004 by wesbed

[Claude]

CD-Rs deteriotate over time, depending on the quality. But manufactured CDs don't, unless there is a manufacturing or storage problem.

The first CDs have been sold in 1983 (I have a few from that year), and so far no widespread deterioration effect has been known. Those CDs that became unreadable were not manufactured correctly.

There are probably collectors on this board who have many CDs that are more than 15 years old. Did you encounter a significant number that became unreadable? More than one?

I'm pretty sure that our CDs will also last the next 10, 20 or even 50 years, if anyone still uses CDs then (their content will probably have been transferred to hard disk juke boxes)

Edited May 11, 2004 by Claude

[Brandon Burke]

I'll be damned. Well I guess I should have looked that up but that would have entailed....looking that up. And I'm at work. Needless to say, I was thinking of JohnJ's initial post and not the rest of the thread. Oh well. Good lookin' out....

[Brandon Burke]

CD-Rs deteriotate over time, depending on the quality. But manufactured CDs don't, unless there is a manufacturing or storage problem.

I have seen cases of 'bronzing' on the part of manufactured CDs.

[wesbed]

I don't have any documentation. However, it seems I read that manufactured CDs should last about 50 years. Maybe my memory is bad or what I read wasn't accurate.

For most of us, 50 years from now, we won't care anyhow. I'll be 88 if I live another 50 years.

[GA Russell]

I have only one CD that is bronzed, a Caravan album. It was purchased in Canada about ten years ago, and manufactured in the EU. So far it still sounds fine. I started buying CDs in '88, and my discs from then all sound good as new.

I am under the impression from discussions with friends that those old enough to have grown up with LPs treat their CDs with the same care; and those too young to have purchased many LPs have treated their CDs more roughly, not concerned about scratches. Perhaps there is something to the argument about storage and handling.

[J Larsen]

My PhD advisor used to be a senior research scientist in the recordable media division of IBM. I know the following to be true, but I can't give you references right now.

In the late eighties, one of the major cd pressing plants used a chemical in the plastic layer that the Aluminum (Al) cd layer is encased in that has a slow reaction with Al. This reaction caused the readable Al layer to become corroded over the course of about 10 [NOTE: typo corrected here to prevent future confusion] years in millions of discs. This is the cause of the "bronzing" problem that you often hear about, and hopefully don't experience. This should, hopefully, affect only discs manufactured in the late 80s through the early 90s. For a limited time I believe the responsible plant offered replacement CDs, but I'm sure the window for that closed a long time ago.

Barring chemical reactions between the protective plastic layer and the "read layer", a properly handled cd should last forever. Plastic does not spontaneously decay - this would imply that it is radioactive which it obviously isn't. The same goes for Al. I think that a big part of why discs don't last as long as their owners expect is that they don't realize that the printed side of a cd is at least as fragile as the read side.

Edited May 14, 2004 by J Larsen

[Brandon Burke]

his reaction caused the readable Al layer to become corroded over the course of about 100 years in millions of discs.

First of all, this is not a flat-out disagreement with you, J Larsen. Just pushing the conversation...

I hear what you're saying but the fact of the matter is that we couldn't possibly know that unless they were testing CD technology in 1904. The only other way to get this figure is by employing accelerated aging which, though useful, really only tells us what happens when you put something in the oven (or whatever else you choose to do). As far as I've heard, the lifespan of a manufactuted CD is closer to 30-70 years. But we have no way of knowing either way. And, as mentioned earlier, it depends on when the CD was manufactured.

As to the comment about reactive qualities of [Al], the technology has not been around long enought to say with any certanty but the argument for gold CD-Rs is pretty clear. Gold is almost completely inert. (And of course this is in reference to CD-Rs only.)

I should add that much of the work that goes into CD longevity--as far as I've seen--is concerned with CD-Rs. This is largely because audio restoration/digitization projects are often commited to CD-R. It's a library/archives/cultural hertiage issue and there's quite a bit of funding to be had for those willing to take on the study. I mean let's face it: the LC, Smithsonian, AMIA, and NARA are more than willing to hear the results of new research. Their asses are on the line.

[Dmitry]

I don't know about CDs, but CD booklets sure are affected by age. I have noticed that paper in few of mine has gotten yellower and lost some of its lustre, especially the glossy paper.

Nothing really terrible, but since we are having this conversation..

[J Larsen]

his reaction caused the readable Al  layer to become corroded over the course of about 100 years in millions of discs.

First of all, this is not a flat-out disagreement with you, J Larsen. Just pushing the conversation...

Brandon - that was an obvious typo - I meant 10 years, hence the bronzing started showing up in the early/mid-90s. My cat likes to sleep on my keyboard, and as I result I have a lot of keys that stick a lot. Sorry for the confusion.

[Kevin Bresnahan]

I've seen this article all over the web. I have to wonder if the music industry isn't behind its publication. What better way to scare people away from burning CDs?

As I've said in other threads, I have many CDs which I bought in the early 80's and all of them look & play fine. I also have many CD-Rs that I made in the early 90's and all are fine, both data & audio. In everything, there is a probability of failure and that includes CDs and CD-Rs. However, I haven't gotten stung myself and I personally have yet to see a problem in any of my friends' collections.

Later,

Kevin

[Harold_Z]

.... I haven't gotten stung myself and I personally have yet to see a problem in any of my friends' collections.

Same here.

2 or 3 posters so far have reported problems? How about all those who HAVE problems post them here. Maybe we can get an idea (whatever the margin of era) of how widespread the problem is. those of you that had problems - did you leave the discs out of the cases? In cars? IOW any relative info that can be of help to us in getting a handle on how widespread this is and what the variables are.

[Claude]

I can imagine that in a few years a lot of people will buy their music exclusively as downloadable files and simply store it on their hard drive without a backup. This will cause many more data loss catastrophies than deteriorating CDs.

Edited May 14, 2004 by Claude

[J Larsen]

I haven't personally experienced the "bronzing" problem, but then again I didn't buy my first CD player until 1996, so I don't have many old cds. I was the only guy in my high school who knew that records were still being made, and the only one who saw any point in buying them.

I have, however, seen collections afflicted with bronzing. I had a roommate who lost a chunk of of his Deutsche Gramaphone collection to bronzing, and I've known a few people whose early editions of their Nurse With Wound cds bronzed. The NWW label is aware of the problem and was still offering replacement discs as recently as 2000; a friend had about a half dozen discs replaced with no hassle other than having to ship his ruined ones to London.

Millions of discs have been affected by bronzing, but when you consider that there are billions upon billions of discs in the world, the probability of any one disc being affected is small, especially considering that no disc produced more recently than the early 90s should be affected.

[LAL]

I have quite a few CDs manufactured in the late 80s/early 90s which are still in top condition and without any hint (touch wood) of deterioration in the aluminium layer or bronzing. Some of these have even been through fairly extensive use and been subject to some wide variations in temperature and humidity. All in, the CDs I have have been quite resilient. Having said that, I am generally putting off buying discs manufactured in the late 80s just in case.

[Claude]

I just discovered the first "rotten" CDs in my collection. A 3CD set from Hyperion Records, with Tatiana Nikolayeva playing Shostakovich´s 24 Preludes and Fugues op.87. This set from 1990 is "Made in England" and was problably made by the Nimbus pressing plant, which was known for it's manufacturing problems in the late 80's.

http://www.hyperion-records.co.uk/details/66441.asp

On all 3 CDs from the set, the laser skips on the last third of the disc, with drop outs increasing progressively. No deterioration is visible.

I will try to extract the CDs on my PC to save the tracks that are intact.

[7/4]

Barring chemical reactions between the protective plastic layer and the "read layer", a properly handled cd should last forever. Plastic does not spontaneously decay - this would imply that it is radioactive which it obviously isn't.

Plastic dries out and becomes brittle.

[LAL]

I was speaking to a friend, who is an opera buff, a week ago and one of the things we discussed was CD longevity. One point brought up that I hadn't heard before concerned his opera box sets bought in the 80s and whose CDs were housed in sponge/foam material. After a long while of not playing the discs, he thought he'd dig them up again to spin. To his horror, the material holding the CDs had gotten stuck to or eaten into the lacquer layer of the CDs rendering them unusable.

Packaging of this type is rare today but a fairly recent one that comes to mind is the Charlie Christian 4 disc Columbia box set (a part of the discs are slotted into a sponge holder). So, if you have the set and haven't transferred them discs to proper jewel casing...

[Brandon Burke]

Barring chemical reactions between the protective plastic layer and the "read layer", a properly handled cd should last forever. Plastic does not spontaneously decay - this would imply that it is radioactive which it obviously isn't.

Plastic dries out and becomes brittle.

There's actually three chemical reactions inplace here:

1. The plastic housing and the binder (adhesive) layer.

2. The aluminum layer and the binder layer.

3. The plastic housing at the aluminum layer.

Can't forget the adhesive. After all, we have the adhesive layer to thank for *sticky shed syndrome* on 70's-era cellulose acetate reel tape. The binder used on this particular kind of tape absorbed moisture and caused the metallic flakes that form the information layer to come off during playback, leaving a black resudue on the heads and capstans.

[andybleaden]

Kind of reminds me of when I was offered a jazz collection to buy by an old wifey whose ex husband had cleared off and left a pile of old records in the shed.

I went on the phone rang her up ...what were they ....thad jones ....lee morgan

They had mushrooms growing on sleeve and record

They had been put in a cardboard box which had had food, and water spilled in it

They were all warped and had been played with a large crochet needle

I gave her a hend to clean out her shed and take everything to the tip for her

I even helped her sweep the shed and took her to the shops to buy some plastioc boxes for the shed too!

Good deeds expelled the desire to burn the shed /house down and I went home and cried ....they were very old and very collectable but I made up a good deal a few weeks later and cleaned up on some old prestige organ dates B)

The cd bronzing thing I have not found an issue with. I do suspect mercenary forces are behind this coming up again across the web in various spooky stories!

Could it be the dark side Master Yoda?

They have done it before under another scheme

sneeky buggers the music industry .

I will stick my old and rare tocj in a moldy room for tenm years and test them!

[BERIGAN]

CD-Rs deteriotate over time, depending on the quality. But manufactured CDs don't, unless there is a manufacturing or storage problem.

I have seen cases of 'bronzing' on the part of manufactured CDs.

I have a few cds from the ASV label that were like that almost from the day I bought them! They still play fine...at least the last time I checked...and who really knows how long these cds will last? BASF used to claim that VHS tapes could be recorded on 600+ times, but I found video lines crop up on some tapes after a few dozen times....many of my Beta tapes from the 80's are almost useless(Been taping some onto DVD's)