WARNING: CD_Rs can go bad suddenly

Are you suggesting here or during manufacture?

Ted

Why do you do this?

Ted

On CD's, the data has always been under the label (top surface)... even with pre recorded 'pressed' discs. The bottom transparent surface can be quite a mess, and they will usually still work... however it doesn't take much of an intrusion through the label side to do one in.

On pressed discs, the reflective layer is put on in some sort of plating process, and the label on that.

CD-r's & RW's have a dye layer bonded directly on the polycarbonate, then the reflective plating & label

Not so sure about DVD though... heard all sorts of wild stories about them.

Here's a pretty good 'FAQ' type thing...

Probably when you had it.

I bought some of those printable-stickon labels so I could personalize my CDs. After reading some of problems a couple of years ago, I threw all that stuff away. I now use pens especially made to write on CDs. Not as neat, but I've only had one bad CD out of the hundreds I've made.

Earle Rich Mont Vernon, NH

I've had to wash mold release off commercial software cd's. I don't use hot. I also had some Wonderware (control software) cd's in the fancy original box which got coated with excess plasticizer from the box. In both cases, washing the cd carefully under lukewarm running water with a dish detergent got them working.

Pete Keillor

On Sun, 02 Nov 2003 15:06:25 +1300, Bruce Simpson wrote something ......and in reply I say!:

Interesting idea. I will remember that. Worth the cost of a few Cds to help ensure the safety of your data

Talking of which. Do not write on CDs with a biro :-<

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On Sun, 02 Nov 2003 04:36:11 GMT, Loren Coe wrote something ......and in reply I say!:

Yes. This is what happened to me with the writing on the CD with biro

I am concerned that even a chemi pen may have long term negative FX!

I assumed a laminated situation as well. Not having that means that you can scracth the bottom of the Cd OK, but be very careful about the top.

I have just tried a spare driver CD. IT also scratched straight through the writing surface.

Sounds like labels are a good idea?

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what about the labels is bad? --Loren

...>>

yes, i wonder about that now. someone said not, but not why. my sample does _not_ seem to have the acrylic overspray mentioned in that CD_R primer url offered here by another poster. this could possibly explain the flaking vs intact results observed by the OP.

--Loren

I'm suspicious about the label adhesive, mostly. Some of these CDs will be stored at the historical society for years. At some time, they will (hopefully) be transferred to some other media. I've had some experience with paper labels falling off other items. Sometimes they take the substrate with them.

Understand, this just a feeling I have. Sticking labels on something that will be inserted into a precision optical reader just doesn't feel right.

I'm now involved in editing and producing a book for our local library, a 100th year history. Along with the book, we are including a CD that includes all the scrapbook scans, extra text, jpeg photos and anything else that didn't fit in the paper version. I want that CD to last a long time. We are having them produced and screened by a local company that makes them by the thousands. Their recommendation was to never use the labels. They might have a vested interest in that advice, but I believe them.

Earle Rich Mont Vernon, NH

Highly unlikely. This one belongs to the set that sits near my desk not in the shop. The strongest solvent that has ever been near it since I bought the 50-stack has been my morning coffee. Mind you, I do like strong coffee. :-)

I'm convinced that this was a manufacturing defect and my point in publishing it is to warn any who care to listen that if machine readable material is worth keeping, it's worth keeping at least two copies.

Ted

Interesting. I think I'll just file this for future reference.

Ted

yes, same here, but nowadays they are mostly permanent, at least unless they state "removable", if a brand name.

i have always told folks that a small label will unbalance the disk, more important with the modern hi-speed drives.

does anyone here have info or experience with the cd labeling "systems"?

these full size labels would add some protection, possibly a lot. again, if a brand name, the adhesive should not migrate. _but_if the foil is _not_ oversprayed, the chance of migration probably outweights any advantage of physical protection. --Loren

On Sun, 02 Nov 2003 06:03:45 GMT, snipped-for-privacy@hotmail.com (Roy) wrote something ......and in reply I say!:

Ah! hmm....as I was starting to suspect.

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In article , Erik wrote: ...>>

i just visited that url again, it confirms my suspicion that cd's are indeed laminated. the bottom plasic is pressed with the data and then overlaid with metal, then topped off with another disk of plastic. the re-writtable are similar, it is just the CD-Rs that are most vunerable to top surface defects. --Loren

....>

At first, just to see if I could, and to find out how they were made. The old CD burner where I volunteer made lots of coasters! My own old 2X burner wasn't much better. The new 52X burner never ruins A CD.

Now, they are a source of clear Polycarbonate, and they can still be used as a coaster!

By the way, I have found that really cheap brands of CDs can lose data over

Steve R.

As long as they are not wet for a long time, they will often survive. Sometimes people bring me computers for repair, and their CDs, have jam, jelly, and other food on them. A quick rinse in soapy often makes them readable again. I pat them dry with paper towels right away. If they get a chance to soak they are ruined.

Steve R.

Don't bank on it. Yes many (most?) CD's are laminated. However if you do some looking you'll find than not all of them are. I learned this the hard way with the very first program CD I ever had. I was handling it carefully from the edges when it slipped and fell to the floor. I saw it was label side down and thought everything was ok. Placed it in the drive and went to loading. I quit half way through. Close examination show that the back was the metal layer and it was extremely thin. It was scratch through in several places. It's usually pretty easy to tell which CD's are laminated and which ones aren't. Just look closely and you can see it.

Wayne Cook Shamrock, TX