Restoring a Damaged CD
updated November 24, '04
Scratches on CDs can hinder playback and ripping. This article
shows how to get rid of them.
EAC excels at finding & reporting errors, but can't always correct them. The correction method EAC uses, is rereading untill the data is correct, but very bad scratches will never return correct data. So after a number of tries EAC will give up its attempts to correct the error and report a Read Error or Sync Error after it has finished ripping.
Let's help EAC by removing the scratches that cause the trouble. This article explains an elegant method which takes only a few minutes and uses brasso to wear away the scratches. Brasso is just a brand of metal polish - in fact any brand metal or copper polish will do!
What about people who don't know the brasso method? What do they do when EAC reports errors? Most don't know what to do. Some try to smooth down errors with a program called Deglitch. This doesn't actually correct the errors but makes them less audible, via interpolation. It may work well for small isolated errors, but not so for large areas of errors such as scratches. Another option is ripping with Feurio or PlexTools, which rip not too damaged CDs easier. Feurio can only report errors - based on C2 info and less reliably than EAC - but not correct them. Plextools works only with Plextor drives. If what you want is removing the scratches, your options are brasso, toothpaste (the method is the same as for brasso, but the results are bad for most brands), or a consumer polishing or professional resurfacing device.
Our ripping guide configured EAC so that, if a read or sync error is encountered in a track, EAC will skip the rest of that track. After we have restored it with brasso, we will rip the bad track anew. This skipping saves you a lot of time.
A CD consists of a reflective silver layer 'sandwiched' between 2 protective layers: one on top (the label side, often decorated with text and colour) and one below (the silver side: thick transparent plastic through which you can see the reflective silver layer). The label side is thin, if a scratch on it reaches and damages the delicate reflective layer (typical is that you can locally look through the CD), the CD is broke and cannot be repaired. The silver side is so thick that scratches on it will not reach the reflective layer. In the worst case they diffract laserlight so that it doesn't reflect properly on the reflective layer, causing read trouble, but that can easily be solved by wearing away the scratch with brasso. Brasso works only for pressed CDs (the ones you buy in a shop), it does not work for CD-Rs.
1. Which Scratch? Try to find out which of the (many) scratches is causing the trouble, because: the fewer the scratches you need to remove, the easier! Look for concentric scratches, because these do more harm than radial scratches (concentric = parallel with the outer edge of the CD, radial = from center to outer edge). On the CD each track circles around the previous one. So, if EAC reports an error on the last track, your scratch must be near the outer edge of the CD.
2. Rub with Brasso. Put some brasso on the silver side, where the scratch is. Rub with a cloth at medium pressure, preferably in radial direction (you know why). If I need to remove a deep scratch I rub in a direction crossing the scratch even if it isn't radial (because that works fastest), but I take care to finish radially (preferably with fresh brasso). As you rub, the fine grit present in the brasso pressed between your fingers and the CD, will wear away some of the plastic layer together with its scratches. You may rub firmly to make the work advance, but hold on long enough to make sure the scratch gets removed. As the brasso gets thicker due to the worn away plastic it will get less grinding, so you might need to add fresh one. Complete removal of a scratch is often not needed to make the scratch harmless.
3. Clean with water. If you think you've done enough, clean the CD with water. Be careful when you wipe off the water (this causes new scratces). A radial direction is again a good idea.
The whole process is a matter of a few minutes. You might feel a little unsure the first time you try it, but don't worry, it is something easy to learn. I have only done a few CDs and I'm already able to write an article about it, so it can't be really difficult ;-) Take your time to learn for that first CD, with the next CDs you will be self-confident, fast and effective. Now that this article is finished, you are able to create flawless rips, even from scratched disks. Not bad huh? ;-)