Do unburnt CD-R discs have a shelf life ?

Hi,

I have been noticing the following strange problem with
my stack of unburnt CD-R disc over the past couple of
years.

If I leave a stack of CD-R discs on my desk in my room,
in its spindle with the cover on, after a couple of weeks
the top few CD-R are not recognised by the CD burner, as
being valid blank discs. This problems occurs for almost
any brand.

Sometimes I get a spindle in which every alternate disc
is not recognised by the CD burner. I have had this
across different CD burners both branded such as Yamaha
4416s , and generic types. I have used two different
computers during this period and have the problem with
both.

Could some one explain what may be the probable cause or
point me to some documentation that discusses such issues.

regards
bt

What kind of light is getting to the CD-Rs? While CDs may not be suceptible
to electromagnetic problems, they are prone to light and heat damage.

Also, what brand are they? Generic brands will have a higher failure rate
than "premium" brands.


"B Thomas" wrote in message
...
Hi,

I have been noticing the following strange problem with
my stack of unburnt CD-R disc over the past couple of
years.

If I leave a stack of CD-R discs on my desk in my room,
in its spindle with the cover on, after a couple of weeks
the top few CD-R are not recognised by the CD burner, as
being valid blank discs. This problems occurs for almost
any brand.

Sometimes I get a spindle in which every alternate disc
is not recognised by the CD burner. I have had this
across different CD burners both branded such as Yamaha
4416s , and generic types. I have used two different
computers during this period and have the problem with
both.

Could some one explain what may be the probable cause or
point me to some documentation that discusses such issues.

regards
bt

On Wed, 11 Jan 2006 06:05:15 GMT, Erick wrote:
What kind of light is getting to the CD-Rs? While CDs may not be suceptible
to electromagnetic problems, they are prone to light and heat damage.

Mostly indirect (reflect), halogen (I think sodium vapour, yellow) light
from my table lamp. The spindle is not under the lamp directly.


Also, what brand are they? Generic brands will have a higher failure rate
than "premium" brands.

Yes I do have more problems with generics. Having experienced these
problems I have been purchasing branded CDs such as Sony or Immation
etc. All have the problem. I wonder if it has some thing to do with the
fact I some times smoke at my computer. This may explain, some clouding
of the CD burner lense but I do clean it regularly, using the brush
type cd.

Can light effect CDs in a spindle, lying with their metalic side face
up. I mean not just the top most CD but the top few (3-5).

The problem is pretty bad 1 in 2 CDs I have to throw.

regards
bt

Smoking nearby could be the problem, and for that matter, could cause
serious problems for the PC down the road (I'm a smoker too, but never
around the PC). Nicotene tar craps up more than just our lungs.

In all honesty, you've ruled out light and generic disks. Besides smoke, I'd
be looking at the drive as the culprit, and the fact it's the top disks
you're having trouble with as a mere coincidence.

"B Thomas" wrote in message
.. .
On Wed, 11 Jan 2006 06:05:15 GMT, Erick wrote:
What kind of light is getting to the CD-Rs? While CDs may not be
suceptible
to electromagnetic problems, they are prone to light and heat damage.

Mostly indirect (reflect), halogen (I think sodium vapour, yellow) light
from my table lamp. The spindle is not under the lamp directly.


Also, what brand are they? Generic brands will have a higher failure rate
than "premium" brands.

Yes I do have more problems with generics. Having experienced these
problems I have been purchasing branded CDs such as Sony or Immation
etc. All have the problem. I wonder if it has some thing to do with the
fact I some times smoke at my computer. This may explain, some clouding
of the CD burner lense but I do clean it regularly, using the brush
type cd.

Can light effect CDs in a spindle, lying with their metalic side face
up. I mean not just the top most CD but the top few (3-5).

The problem is pretty bad 1 in 2 CDs I have to throw.

regards
bt

To do a good lens cleaning you have to open up the drive and use a cotton swab with some glass cleaner.

Erick wrote:

Smoking nearby could be the problem, and for that matter, could cause
serious problems for the PC down the road (I'm a smoker too, but never
around the PC). Nicotene tar craps up more than just our lungs.

In all honesty, you've ruled out light and generic disks. Besides smoke, I'd
be looking at the drive as the culprit, and the fact it's the top disks
you're having trouble with as a mere coincidence.

--
Mike Walsh
West Palm Beach, Florida, U.S.A.

On Wed, 11 Jan 2006 13:44:01 GMT, "Erick"
wrote:

Smoking nearby could be the problem, and for that matter, could cause
serious problems for the PC down the road (I'm a smoker too, but never
around the PC). Nicotene tar craps up more than just our lungs.

In all honesty, you've ruled out light and generic disks. Besides smoke, I'd
be looking at the drive as the culprit, and the fact it's the top disks
you're having trouble with as a mere coincidence.

"B Thomas" wrote in message
. ..
On Wed, 11 Jan 2006 06:05:15 GMT, Erick wrote:
What kind of light is getting to the CD-Rs? While CDs may not be
suceptible
to electromagnetic problems, they are prone to light and heat damage.

Mostly indirect (reflect), halogen (I think sodium vapour, yellow) light
from my table lamp. The spindle is not under the lamp directly.


Also, what brand are they? Generic brands will have a higher failure rate
than "premium" brands.

Yes I do have more problems with generics. Having experienced these
problems I have been purchasing branded CDs such as Sony or Immation
etc. All have the problem. I wonder if it has some thing to do with the
fact I some times smoke at my computer. This may explain, some clouding
of the CD burner lense but I do clean it regularly, using the brush
type cd.

Can light effect CDs in a spindle, lying with their metalic side face
up. I mean not just the top most CD but the top few (3-5).

The problem is pretty bad 1 in 2 CDs I have to throw.

regards
bt


You'll notice on the unbranded discs that you can actually see right
through the disc. That means that there's some light leakage through
the foil. Whether this is in the spectrum range that can affect the
dye, I don't know. I still kind of suspect it's the smoke. I store
my discs near a similar lightsource and never had a problem.

With optical discs, there's two surfaces you have to worry about the
most. The lens, which you say you clean on a regular basis, and the
polycarbonate on the write surface. Some CDs are designed to rest on
their hub in the stack, allowing a small airspace between discs to
keep them from scratching. If you're like most people, and buy the
spindleless stacks in shrink wrap, you probably unwrap the top few for
access and leave the rest of the shrink wrap in place to keep the
stack secure. That allow the smoke to contaminate the write surface
with cigarette tar on the exposed discs. You can test this by running
a isopropyl alcohol soaked paper towel over one of the discs that you
find has failed. You can either clean the discs prior to use with
this method, or you can put your blanks in an old CD "cakebox".
They're not airtight, but having the cover on will probably help.

Caveat: Don't smoke, so this is all speculation.
---------------------------------------------
Thanks.


MCheu

Paper towels, alcohol, and ammonia should not be used on plastic optical devices.
It is better to use a glass cleaner that does not contain ammonia, e.g. Glass Plus, and a cotton cloth.

MCheu wrote:

You can test this by running
a isopropyl alcohol soaked paper towel over one of the discs that you
find has failed.

--
Mike Walsh
West Palm Beach, Florida, U.S.A.

On Wed, 11 Jan 2006 07:58:48 GMT, B Thomas
wrote:

I wonder if it has some thing to do with the
fact I some times smoke at my computer. This may explain, some clouding
of the CD burner lense but I do clean it regularly, using the brush
type cd.

The smoke may be a problem, as may the cleaning with the
brush CD. Those brush cleaners are generally only a
temporary fix as they may degrade the lens if they're
effective at cleaning it at all.



Can light effect CDs in a spindle, lying with their metalic side face
up. I mean not just the top most CD but the top few (3-5).

The problem is pretty bad 1 in 2 CDs I have to throw.

yes if you put a stack of CDs were light shines on them
you'll see the light shine through the sides. It's not
supposed to degrade them fast enough to matter, but theory
about ideal discs and reality of those on a store shelf may
differ. You need some controls in place to isolate this,
like getting another drive and trying the disc the current
drive rejects, and getting a new spindle and storing half
out in the open room light and the other half covered from
all light.

It may well be that each degrades the discs some and the
combination effect is the worst. Then again, maybe it's
just that yours had a bad dye batch or something, it'd take
a lot of discs to find out and you might not even be using
the best disc for your burner regardless of the other
factors.

Yes I do have more problems with generics. Having experienced these
problems I have been purchasing branded CDs such as Sony or Immation
etc. All have the problem.

General rule of thumb is "Made in Japan" means decent quality disks. I got
tired of all the CD's that would work for about a month and then fail, so I
decided to stop being cheap and picked up Kodak disks figuring a company
like that would have some quality behind them. I check the manufacture code
on the disk and they were exactly the same as the no-names I had been buying
previously. That's when I learned to look for "Made in Japan" as a starting
point.

I wonder if it has some thing to do with the
fact I some times smoke at my computer.

Depending on how much you smoke. Definately something you should consider
quitting anyhow.

: )

This may explain, some clouding
of the CD burner lense but I do clean it regularly, using the brush
type cd.

Bad news. That little brush slapping against the lens can knock it out of
alignment. *IF* you are going to use one of these you shouldn't need it more
than once a year.

Can light effect CDs in a spindle, lying with their metalic side face
up. I mean not just the top most CD but the top few (3-5).

It can, but in reality I doubt it unless you're talking about direct
sunlight for days, etc.

I'd consider faulty software (uninstall/reinstall your burning program),
then consider getting a new drive. DVD writers are cheap and a blank DVD is
the same price as a blank CD these days.