Interesting blank disc failure

[NJRoadfan]

I have a spindle of Memorex DVD+Rs laying around here (RitekF16) to burn disposable stuff. Tonight I just tried to burn a few discs and they all took a long time. I flipped the blanks over and noticed that somehow the bottom faces of the discs have an imprint of the front face of the disc below them!

I'm guessing this is from age and off gassing of plastics as the spindle is about 5 years old now. The last disc on the bottom of the spindle appears unaffected. These discs weren't stored in any extreme conditions either. Weird.

[NJRoadfan]

Check out that haze. You can even make out the "DVD+R" silk screening.

[lordsmurf]

A lot of disc have the so-called "bleed-through", but it's just the translucence of the dye. It's only unusual if you're used to MCC/MKM and Taiyo Yuden media. Actually, TY media is fairly translucent too, but you just never notice because it's rarely used for branded media (silver matte, silver shiny, inkjet surface). RitekF is Fuji oxonol (the "F" in the media ID), and oxonol is not a darker dye.

That part is nothing to worry about.

The scuffing of a polycarbonate (the "hazing" you see) is likely either defective media from the manufacturer or circular micro-scarring of the media while it was on a spindle.

If you want me to look at it more in depth, send a disc here. PM me.

I'm curious how the burned media would fair in PIE/jitter scans. It may be crappy media. While RitekF is good, it's not flawless. Ritek still lets out too much imperfect media, especially to bottom-barrel brands like Memorex. Even the office supply store brands tend to use better RitekF grades. (Ritek is one of the only manufacturers to have grades. MCC, by contrast, throws away crap media. It doesn't sell it for less $$).

[NJRoadfan]

I can confirm that the burns were bad. They failed verification with a retry timeout and a DVD-Video player chocked on it. That haze wouldn't rub off the disc either. I'll grab a few blanks and send them out as I'm going to toss the spindle anyway. I never had a problem with burns from this batch.

This problem seems to be recent because looking at older burned discs, they don't have the haze/imprint at all. Just a nice shiny purple bottom. My MCC media stored on the same shelf is problem free.

[lordsmurf]

I know what this is.

First, the disc is not cloudy. And there's nothing in the dye, or even in the polycarbonate. The disc has not aged or died in any way.

So what is it, you ask?

There's a fine chemical mist on the bottom (and thus tops) or the discs. What it is, where it comes from, and when it happened is what we have to piece together. You might be innocent, but the odd are against you.

I analyzed the disc, and saw immediately that it had micro-abrasions. Some circular, some not, and it's hard to say what may have been caused by shipping from you to me, as they were not 100% secure on the spindle in transit. I analyzed the discs under two magnifying glasses of varying powers, and felt the discs. I saw fine specks/dots, and it felt slightly sticky to the touch.

I ran the disc under water in the sink, then scrubbed it. No change.

Then I ran the water, and held the disc under the water while scrubbing with a dish rag. Almost all of the specks came off. I added some nasty scratches, of course, but the "cloudy" part went away. It appears to be some sort of water-soluble glue.

Have you ever applied one of those spray coatings to inkjet discs?
Or have you ever stored other discs in the spindle? Possibly the aforementioned inkjet discs?

Something we've never really talked about is those coatings, and how the can damage drives and other items in an enclosed environment. It's possible, for example, for still-wet (even minutely!) spray-coated inkjet discs to have the spray evaporate inside an enclosed spindle, and the glue to settled. This spindle has an evaporate pattern to the glue droplets.

So we know what, but not when it happened.

If it was "fine" at an earlier time, you did it somehow. This is unfortunately one of this biggest issues when it comes to media degradation issues -- faulty memory.

If it was not fine earlier, then it may have been contaminated at the plant where the Memorex discs had the label applied, given how it's on both coated sides. Either the discs were hit by a spray on the side, or something pooled somewhere. And the pooling evaporated on the trip from Asia to your house.

It had to happen when the discs were on the spindle, as none of the hubs show issues. Those are clean.

Not what you wanted to hear, I'm sure, but that's what it was.

Yes, the discs are useless as is. Trying to clean them manually would scratch them, too. And using a resurfacing machine would not be worth the cost. Just throw it away, and buy more.

I've only seen one case of degraded media in the past 13 years, with no other possible explanation.

[NJRoadfan]

Quote:

Originally Posted by lordsmurf

I know what this is.

First, the disc is not cloudy. And there's nothing in the dye, or even in the polycarbonate. The disc has not aged or died in any way.

So what is it, you ask?

There's a fine chemical mist on the bottom (and thus tops) or the discs. What it is, where it comes from, and when it happened is what we have to piece together. You might be innocent, but the odd are against you.

I'm listening...

Quote:

I analyzed the disc, and saw immediately that it had micro-abrasions. Some circular, some not, and it's hard to say what may have been caused by shipping from you to me, as they were not 100% secure on the spindle in transit. I analyzed the discs under two magnifying glasses of varying powers, and felt the discs. I saw fine specks/dots, and it felt slightly sticky to the touch.

I ran the disc under water in the sink, then scrubbed it. No change.

Then I ran the water, and held the disc under the water while scrubbing with a dish rag. Almost all of the specks came off. I added some nasty scratches, of course, but the "cloudy" part went away. It appears to be some sort of water-soluble glue.

Have you ever applied one of those spray coatings to inkjet discs?
Or have you ever stored other discs in the spindle? Possibly the aforementioned inkjet discs?

I have never used spray coatings. Heck I have never used inkjet discs. Nothing besides those blanks were stored in that spindle which was stored on a shelf near the computer.

Quote:

Something we've never really talked about is those coatings, and how the can damage drives and other items in an enclosed environment. It's possible, for example, for still-wet (even minutely!) spray-coated inkjet discs to have the spray evaporate inside an enclosed spindle, and the glue to settled. This spindle has an evaporate pattern to the glue droplets.

So we know what, but not when it happened.

The "when" is likely the past year or so, I infrequently burn DVDs so I can't pin down a date. The spindles of Verbatim DVD blanks stored next to it that are about 3 years old now are unaffected.

Quote:

If it was "fine" at an earlier time, you did it somehow. This is unfortunately one of this biggest issues when it comes to media degradation issues -- faulty memory.

If it was not fine earlier, then it may have been contaminated at the plant where the Memorex discs had the label applied, given how it's on both coated sides. Either the discs were hit by a spray on the side, or something pooled somewhere. And the pooling evaporated on the trip from Asia to your house.

It had to happen when the discs were on the spindle, as none of the hubs show issues. Those are clean.

Not what you wanted to hear, I'm sure, but that's what it was.

Yes, the discs are useless as is. Trying to clean them manually would scratch them, too. And using a resurfacing machine would not be worth the cost. Just throw it away, and buy more.

I've only seen one case of degraded media in the past 13 years, with no other possible explanation.

What I can add is the recordable side of the disc at the bottom of the spindle was not affected. I landed up burning it the night I discovered the problem. The spindle is quite old, likely dating back to 2008. My theory was the top silkscreen layer somehow degraded over time and off gassed/leached out over the disc above it.... or it was some mysterious Brazilian mold . No loss, but it is the first time I've had blanks "go bad" due to age.