Repairing scratched CDs and DVDs

[stopthegop]

Hello,

I've been going through my CD and DVD collection (which is massive, dating to pre-digital) the last couple of weeks and I'm in the process of organizing everything and copying the entire collection to digital linear tape, and eventually into a small 30-50 element robotic tape library.  One problem I'm having is with scratched media.  I'm curious what methods other people use to fix CDs like this?  I've tried a few different things for this.  Interestingly I've had the best results with...  clear KY lotion and a clean Chamois.  Its saved about 75% of the discs I've tried it on... But that leaves the 25% still at least partially unreadable, including some extreme rarities (Metallica - the 5.98 LP/9.98 CD, c. 1985), live G. Dead, etc..   Any ideas on how I might revive these old discs?    

[rkauer]

Believe me, works:

- Toothpaste applied with one finger over the scratch. Rub it smoothly. Wash it;

- Take some polish liquid (like car repaint ones) and softly rub it with some cotton.

- Clean the now polished surface with some clean cotton. :-D

[orange]

there are specialized kits for that, I tried one that is automatic, it has a motor, 2 types of disks liquids (one for cleaning other polishing).
It cannot repair badly scratched disks, and it needs several cycles for others, but IMHO at least its safer than DIY solutions.

[Zac67]

I've successfully used
- a (very) small amount of oil (preferably vegetable, must be acid free), just enough to lubricate a finely scratched surface - can be removed afterwards - use max 4x reading mode / 1x DVD
- polish for cell displays or wrist watches

Only polish in radial, never in tangential directions!

[weirdami]

I've been going through my CD and DVD collection (which is massive, dating to pre-digital)

Can I have one of your analog DVD's?

[Damion]

weirdami wrote:

I've been going through my CD and DVD collection (which is massive, dating to pre-digital)

Can I have one of your analog DVD's?

I'm assuming he meant as in ADD or AAD.

Anyhow, I tried Vaseline in the past, and it worked well.

[spirantho]

Be warned that a few of your CDs and DVDs may be starting to decay by now as well (if you see shadows on the disc surface it might be a good time to make a copy). I suspect it's much the same problem as Laser Rot and as such pretty unfixable for most mere mortals.

I personally reckon within another 30 years or so the only good video media from before the mid 90's will be CEDs as they're grooved not magnetic (loses magnetism) or optical (glue goes icky - "Laser Rot" and stuff)... but of course nobody really knows because they're still too young....

[stopthegop]

Thats exactly why I want everything backed up on dlt.  It has a shelf life of 50 years and 1,000,000 hours mtbf.  But like you say, how do they really "know" that?

[AmiGeezer]

This company I cannot recommend highly enough - www.three-r.co.uk

They actually completely resurface the disc (none of this polishing rubbing malarky) - I've used it to have an xBox360 game disc repaired that had a very deep circular scratch (it's a design flaw of 360's, do a Google).

They repaired the disc for 2.50 GBP + return postage - t he price drops the more discs you send.

Considering to buy the game again would be around 40 GBP, I think that's excellent.

They're service was quick and the quality of work excellent.

Matt

stopthegop wrote:
Hello,

I've been going through my CD and DVD collection (which is massive, dating to pre-digital) the last couple of weeks and I'm in the process of organizing everything and copying the entire collection to digital linear tape, and eventually into a small 30-50 element robotic tape library.  One problem I'm having is with scratched media.  I'm curious what methods other people use to fix CDs like this?  I've tried a few different things for this.  Interestingly I've had the best results with...  clear KY lotion and a clean Chamois.  Its saved about 75% of the discs I've tried it on... But that leaves the 25% still at least partially unreadable, including some extreme rarities (Metallica - the 5.98 LP/9.98 CD, c. 1985), live G. Dead, etc..   Any ideas on how I might revive these old discs?    

[yogisumo]

I've destroyed a number of old cds and dvds to see how they were made.  For cds, they're basically a piece of plastic with a very thin reflective layer on the very top.  Very easy to damage on the top where all the data is.  DVDs, seem to be better.  The top usually has an extra coat of plastic over the reflective layer.

Anyway, to make a short story long, I've repaired a number of scratched cds by polishing them with a dremel tool with a cloth polishing wheel.  ONLY the cloth wheel works.  DO NOT stay in one spot, keep it moving.  Use lowest speed.  For deep scratches that aren't easily fixed with the dremel alone, toothpaste or very fine sandpaper (1500) followed by the dremel works for me.

The commercial kits essentially do the same thing.  An abrasive and a polish.  I think that they do a better job but they cost a lot more also.  Last time I saw a machine, it was @$100CDN and the refills for abrasive and polishing wheels were fairly expensive.

Best option is to not scratch them in the first place.

Good luck.