Wright's Silver Polish

[Gorganzola]

About a year ago I started burning my VHS collection to dvd. After reading a lot of theories, folklore, rumors, etc. I decided to start checking some burned dvds from about a year ago for errors. My technique was to simply attempt to copy the dvd files to my pc with DVD Decrypter. I have been through about 30 so far and all but two have copied without errors. The media I used was basically whatever was cheap, mostly Princo -R and OptodiscOp2 +R from Compusa, and Memorex (Ricohjpnr01) +R.

The two I had problems with were the Compusa media, 1 each Princo -R and OptodiscOp2 +R. Both developed hundreds of read errors near the end of the recording, with some near the middle. First, I washed the discs with soap and water. No improvement. Then rubbing alcohol. Still no. I examined the surfaces under magnification and did not see any sign of dye contamination (moire patterns or rainbows). I did see, however some barely noticable smudges that would not come off with soap and water or alcohol. Soooo, with nothing to lose, I tried some Wright's liquid silver polish - you know, the stuff for polishing silverware. I used it just like as is I was waxing the car: with a kleenex, small circular strokes with light-medium pressure. Let it dry to a haze and buff off with a clean kleenex. To my utter amazement, one of the discs read perfectly with zero errors and the other copied with 22 unrecoverable read errors where there had been over 680 errors before!
I watched the part of the movie where the 22 unrecovered sectors were and saw a couple of barely noticable glitches on the screen -thats' it.

Just to try to eliminate any coincidences that might have been responsible for my success I'll mention this: I have 3 drives for reading dvds: Samsung SD616E DVDrom, NEC 2500A burner and a NEC 1300A burner on a USB 2.0 adapter. When I check the dvds for errors I start with the worst and work up to the best. In my experience the Samsung dvdrom is the worst and the NEC 1300A is the best for reading. The 1300A will read discs without errors that the other two had read errors. When the 1300A won't read it, I know there's a problem with the disc.

My conclusion is that I think media defects are blamed for a lot of problems of so-called "deterioration" when the actual problem is contamination on the surface of the dvdr and it can be fixed by cleaning. Your results may vary, but before you throw away what seems to be a hopelessly unrecoverable dvdr, give this method a try. If you are successful, I'd be interested to hear.

[BJ_M]

it is basicly very fine rubbing compound

[cal_tony]

Thanks for the info, to add to this, I have done a similar check with some of my older writes. These were on +rw as the cost difference and write speeds at that time was negligible between the +r and +rw. I noticed the same thing with some of these older disks that had errors-- they were cloudy. I tried a number of products to clean the disks with varying degrees of success. My biggest problem seemed to be with the circular marks I introduced into the disk by rubbing to hard, or whatever, so I have set these disks aside and every now and again I pull them out and try a different product or a different technique. The advantage of using the +rws to begin with, is that over time I have revived some of these disks so that they can be written to again without errors.
Further, some of these older disks would no longer play in my stand alone players(they were not recognized as dvds) but were recognizable by my PC. I copied these to my hard disk, re-wrote them back to the same disk and Lo and behold they played just fine on my stand alones.

What I have been doing lately is using the clear plastic fillers that are at the top and bottom of dvd packs to see what works best to clear up the hazing effect that occurs over time to the plastic.

[cal_tony]

To add to my post above, my reason for using the clear blanks is than since they are clear and seem to be the same material as the disks themselves it is easier to check your results using new cleaning compounds.
Also, It doesn't clean or polish the disk, but Silicone spray does fill in the small scratches and make the disk easier to read. In some cases washing with soap and water and spraying with the silicone was enough to make the disk PC readable again.