Bad bonding cause for concern?

vbimport

#1

Hi guys. I have read some threads about bad bonding (especially of TY DVD+/-R) and am wondering if this really is a cause for concern?

First of all, I suspect the term bonding applies to how 2 pieces of a disc are glued together? Today I forcefully “unbound” a couple of TY T02 discs with a sharp knife and I noticed that this didn’t cause any noticable(!) damage to the dye (or whatever the part that you can write to is called). After that I partially pulled apart a T02 with my fingernails and ran it through a CD-DVD Speed PIE/PIF test and checked the CRC sums of the files, no problem whatsoever.

When pulling such a DVD+R disc apart, I notice there is a silver layer on top of the dye, I suppose this is the reflective layer? Suppose at one point in time one of my T02 discs’ bonding fails and I get 2 halves, 1 with intact dye and reflective layer…could I still save the data? Perhaps use some superglue temporarily? :stuck_out_tongue: What would happen if I put the bottom half only in a drive?

When the reflective layer is exposed to the air, does this cause more degradation? In any case, I’m going to keep this partially pulled apart disc and rescan it in a couple of years.

Is there a way to see or hear that a disc has bad bonding, prior to burning?

BTW, I rescanned a dozen of T02s (FUJI and Plextor) that I burned and scanned 2 years ago with no noticeable increase in PIE/PIF. That reassures me a bit that my data is relatively safe (I only use T02s and TY CD-Rs). :slight_smile:


#2

I would think twice about putting a damaged disc in any of my newer drives. A shattered disc or flying bits of ink, dye or reflective layer could damage the drive.

Like you, I have found T02 discs are very reliable. My old 4x TY T01s are also doing well.


#3

There are different thoughts on what is good Bonding and what is bad Bonding, and which DVDs are in which category.

Many of the earlier DVDs had some really excellent Bonding, then there was a brief period of very questionable Bonding, and then a new type of Bonding was introduced which was good for some people while many still preferred the original Bonding.

Later two types of Bonding have been used, first TD Bonding and then PB Bonding and it’s debated as to whether these Bondings were good or bad, but in my experience both types of Bonding were quite good.

DC Bonding has just been introduced and people have mixed experiences with this type of Bonding.

This information may or may not be relevant after April 1st.


#4

Edit: I think Drage has some “Bonding” issues of his own :stuck_out_tongue:


#5

I only pulled it apart slighty near the inner ring up to 1GB or so. The disc still feels sturdy. I was mainly interested to see if it would cause elevated PIE/PIFs at the start of the test, it didn’t.

edit: I’m not really into your kind of “Bonding” DrageMester. :stuck_out_tongue:


#6

I am :flower:


#7

[B]Hitokiri:[/B]

[B]RJW[/B] gave a suggestion for testing but I have not managed to replicate it with my own TYs.

http://www.cdrlabs.com/phpBB/viewtopic.php?t=20515

Exposure of reflective layer will result in oxidation which will mean lowered reflectivity and eventual read failure. The dye layer may also become more susceptible to chemicals in the environment as a result.


#8

Thanks TL0. The disc I damaged does indeed make a queeking noise. I guess I’ll have to test all my DVD+Rs now. :doh:

Exposure of reflective layer will result in oxidation which will mean lowered reflectivity and eventual read failure. The dye layer may also become more susceptible to chemicals in the environment as a result.

That’s not good… :frowning:

Is it true what I read, that TY DVD+Rs have better bonding than their -R counterparts?


#9

I heard that TYG02 has the worst bonding, and that YUDEN000 T02, TYG03 and YUDEN000 T03 are all better. But I haven’t used much TYG02, so I’m not quite sure about it.


#10

I’ve used about 150 or more TYG02. It has never split apart on me. But I do think that it would be easy to take apart with my fingers.


#11

OMG! This will probably rate as #1 in my “[I]finest tongue-in-cheek jokes from [B]DM[/B][/I]”. :clap: - I’ve just waken up all the neighbours, dogs and cats included, even the deaf ones, by laughing out loud. :bigsmile: Thanks DM. :cool:

Kudos to [B]Hitokiri[/B] too, scanning partly splitted discs, great stuff. :cool: (I realize you’re serious, just that the thought is funny :flower: ).

Too bad I missed the 1st april party… :frowning:


#12

Sidenote: I don’t think I have ever seen reports of problematic bonding with TY +R, only -R, even specifically only for TYG02. Not 100% sure about that though.

Personally, never had issues with T02. I don’t consider TYG02 as “tough enough in my book” though.


#13

FWIW, I did split a disc in half once and scanned it in an 18A1P.

I can’t remember the disc manufacturer (it was several months ago) but I was likely a Ritek R04, or AML002, UME01, something cheap I could test with.

I’m not sure the reflective layer came off, because I remember just pulling clear polycarbonate (with a slight hue) off the top layer, so perhaps the reflective layer was still attached to the bottom. Can’t say for sure, I wish I’d have taken pics.

Nonetheless, the Liteon scanned the 1/2 thick disc. The results were something like 200k PIE, 10k PIF (the original scan was something like 20k PIE, 2k PIF before I split it), but no huge spikes and a flawless TRT.

I did have a hard time getting the drive to work 100% after that. It was sporadic at best, and wasn’t until a month or so later (about the time I ordered a new drive) till it started working good again. I sold it to a friend. I wouldn’t recommend using a defective disc.


#14

I’m glad somebody enjoyed it! :smiley:


#15

You seem to be easily amused though. :bigsmile:

adelphia83, did you happen to test the integrity of the files on the disc too?

Anyone out there who is brave enough to split a TY DVD disc and scan it? :stuck_out_tongue: I’m curious what result that would yield.


#16

+R and -R doesn’t matter. I have had more problems with -R. But then again I had some f* up batches.

Is bonding a problem yes.
I haven’t tried reading that TY disc that fell a part. However it is quite questionable to put it in your drive. Specially high speed drives.

So how much problems will this do ?
Well if you have the perfect silver layer the change of oxidation is small.
However the real life situation ain’t that nice.

What about glueing it back. Well you probably are going to bend the thin layers slightly during the glueing which might have serious consequences. seeing how a normal twin layered disc allready has problems when it comes to labeling !

For the folks who say T02 is free of problems. Maybe I should put up some new pics. Then again I have to much stuff on my hands.


#17

Actually, silver and aluminum both oxidize rather readily in normal room air - so I think the delaminating issue will have a noticeable effect on the readability of a DVD after a few years, possibly sooner.


#18

Yep, I could read back the entire disc at max speed without problem. The half disc is a lot flimsier than you’d think, I woulnd’t imagine anything stored on it would be good for long.


#19

[OT]

You know we think you’re funny really :flower:

[/OT]


#20

Seems pretty obvious. I lean towards the “sooner” figure, even a matter of a few weeks in some instances, if the humidity levels are > 50%.

As for the split-in-half-on-purpose discs, I’ve done that a couple of times out of curiosity, and firstly all came out with the dye split in several pieces as well (some of the dye sticking to the top polycarbonate layer and some to the bottom one…), and secondly I certainly never thought of putting any of these… things in any of my drives. :rolleyes:

Mabe I’m not that much of a CD freak after all. :confused: :bigsmile: