CD Rot?

[shredking9000]

On one of the forums I frequent, the topic of CD rot comes up pretty frequently. While the term sounds pretty self-explanatory, it occurred to me that I don't know specifically what it is/how it presents itself. On a couple CDs I have there is what looks like a black burn mark on the edge of the disc. Would this be considered CD rot? If not, what would?

[The Great Owl]

I own over 1,000 CDs, and I've bought and sold many more than that since I started collecting them in 1988.

I have never, not even once, experienced disc rot.

That's not to say that it does not happen, but I'm inclined to think that the instances are few and far between. The apparent signs are pin-prick holes or discoloration of discs (resembling coffee stains). These may cause a CD to skip.

[billy35]

I recently noticed this exact spot on one of my cd`s

http://i.imgur.com/FP7aW1w.jpg

To me, it doesnt look like cd rot or bronzing. It plays fine and this spot doesnt seem to spread anywhere. Could this be just the way it was made?

[Alister_M]

I've got a couple with weird stuff going on, luckily it's always outside the encoded area. For some reason my Slayer - South of Heaven has what looks like thin pencil lines around the edge, that's the only one I'm worried about since it's the original master and if it fails I'll have to hunt down an old pressing since all the newer ones are horribly brickwalled.

I suspect it's caused by intemperate climates, especially cold and damp. Good thing I don't live in a cold damp house any more!

[billy35]

Originally Posted by Alister_M

I've got a couple with weird stuff going on, luckily it's always outside the encoded area. For some reason my Slayer - South of Heaven has what looks like thin pencil lines around the edge, that's the only one I'm worried about since it's the original master and if it fails I'll have to hunt down an old pressing since all the newer ones are horribly brickwalled.

I suspect it's caused by intemperate climates, especially cold and damp. Good thing I don't live in a cold damp house any more!

Yes, humidity can cause problems, just like big changes in temperature both cold/warm. So far I had only few cd`s that "died".. But that was mostly my own fault, because I should`ve done more research before buying them. Apparently all of these discs were made in early 90`s and manufactured by PDO, England. This was a very widespread case of bronzing, rot due to bad manufacturing. No matter where and how well you would keep those discs, they would still go bad, even sealed and mint condition.. Other than that - no problems. I have one release from 1989 and it still goes strong.

[Alister_M]

Originally Posted by billy35

Yes, humidity can cause problems, just like big changes in temperature both cold/warm. So far I had only few cd`s that "died".. But that was mostly my own fault, because I should`ve done more research before buying them. Apparently all of these discs were made in early 90`s and manufactured by PDO, England. This was a very widespread case of bronzing, rot due to bad manufacturing. No matter where and how well you would keep those discs, they would still go bad, even sealed and mint condition.. Other than that - no problems. I have one release from 1989 and it still goes strong.

Yeah it's just pure bad luck when it happens I guess. I've probably had more issues with CDs from Mayking/Nimbus than anything else, they just seem to be a bit flimsy. Then again I have some CDs which are from the mid 80s and they're still mint

[castor]

Originally Posted by billy35

Yes, humidity can cause problems, just like big changes in temperature both cold/warm. So far I had only few cd`s that "died".. But that was mostly my own fault, because I should`ve done more research before buying them. Apparently all of these discs were made in early 90`s and manufactured by PDO, England. This was a very widespread case of bronzing, rot due to bad manufacturing. No matter where and how well you would keep those discs, they would still go bad, even sealed and mint condition.. Other than that - no problems. I have one release from 1989 and it still goes strong.

I have Ozric Tentacles' Erpland CD from 1990 which I think is one of those PDO discs. The label side is bronzed but the playing side isn't, and it still plays perfectly!

[billy35]

Originally Posted by Alister_M

Yeah it's just pure bad luck when it happens I guess. I've probably had more issues with CDs from Mayking/Nimbus than anything else, they just seem to be a bit flimsy. Then again I have some CDs which are from the mid 80s and they're still mint

Thats no surprise, because Nimbus was known for pressing problematic cd`s in old days as well.

Originally Posted by castor

I have Ozric Tentacles' Erpland CD from 1990 which I think is one of those PDO discs. The label side is bronzed but the playing side isn't, and it still plays perfectly!

True, its kind of a gamble. Some of the cds turned unreadable in first few years, while others still play up to this day. Although, bronzing or signs of rot, indicate that it might have shorter life span than those who were manufactured correctly.

In general, all these problems mostly occured in the beginning of cd production and only in some regions. Lessons were learned and when people say that cds rot or go bad universally, they are mostly talking about cd-r, rewritable discs, pressed cds mostly from early 90s and specifically PDO, or about something that was abused and kept in bad conditions. If the cd is manufactured properly and kept in good conditions (humidity, temperature, avoiding direct sunlight), it should last for decades. I mean, there are collectors who have thousands of cds and a lot way back from 80s, if it was a widespread thing with all of the discs (like some articles try to point out), accordingly, a widespread wave of reports would come from all places - "Help, everything rots and smells bad." No such thing so far, apart from isolated and well known cases.

[CV19]

The only CD's I have had problems with were from the "Now That's What I Call Music" 10th Anniversary discs which were released in around 1993. They developed what I can only describe as a 'misty' appearance on the playing surface which prevented it from being played all the way through.

Other than that, out of many hundreds of CD's I have, I don't recall any other issues. I have them going back to 1983 (which is I think when they were introduced), and they are still in mint condition and play perfectly.