Repairing Scratched CDs

TOOTHPASTE WORKS: Use colgate total.

These notes are about reparing CDs and DVDs. This is a project in progress, so don't do anything I describe here. Just consider it research results that you can use to try and fix your CDs. Also, check out CdRisks, to read a few notes about the dangers of CDR.

I got most of these ideas from CD Faq by Sam Goldwasser [1]

experiment 1: toothpaste Buffed the CD surface with toothpaste. Crest gel is highly abrasive, and completely unacceptable. Regular AquaFresh? is better, but leaves a pronounced haze. The paste washes clean under water.

experiment 2: video head cleaner Rubbed a scratched surface with this alcohol based solution. It had no effect. Rubbing it with chamois cloth introduced scratches, as there was probably dirt on the cloth.

experiment 3: heat Passed the surface over an open gas flame. The CD, surprisingly enough, is very heat resistant and does not catch fire. It takes around 30 seconds before visibly warping. The surface smooths down somewhat, but the CD appears to warp and buckle slightly. Scuff marks (from the toothpaste) felt less "scratchy", but deeper scratches were unaffected.

experiment 4: talcum powder Used a generic talc with cornstarch and baking soda. Mixed powder with some water to form a paste. Mild rubbing had no effect, but vigorous rubbing left a slight haze. This looked promising.

experiment 5: plastic eraser Used a "plastic eraser" -- the white kind, not the pink kind -- to buff down the surface. The eraser left a pronounced haze with no visible scraches. It seemed to reduce the scratches somewhat, but the haze is very prominent. I think it contains very tiny abrasives, and deposits matter on the surface.

experiment 6: scratched CD Intentionally scratched a CD-R of music with a needle until it would skip tracks reliably. Tried to buff the scratches away with toothpaste (which I thought was not very abrasive). Did not work.

experiment 6: buffing wheel Used a handdrill buffing wheel to buff the CD surface (of another CD-R, not the music CD-R.) The buffing scratched the surface considerably, but also reduced the scratches that were on the CD. I tried to put some toothpaste on the surface, and then use the wheel on it. The scratching increased.

Toothpaste, it turns out, is extremely abrasive and cannot be used as a rubbing compound on CDs. I cleaned the wheel a little bit by rubbing it on a surface, then applied the white stick of rubbing compound (which I think is called Tripoli). I buffed the CD again. This time, the scratching was far less pronounced, and was more of a haze than scratching. It looks like residual buffing compound from previous use was scratching the surface. A clean wheel would probably solve this problem.

The residue from buffing can be cleaned with a little 409 or similar degreaser. Apply a little with your finger, and rinse under running water.

I applied more white compound, and buffed the music CD-R. After around 30 seconds of buffing, the CD warmed up, so I paused, and then buffed again. A total of 90 seconds of buffing seemed to reduce the scratching significantly. I stopped, removed the compound, and tried to play the CD in a cheap player. It succeded.

I believe that another minute of buffing would have rendered the scraches nearly invisible, or at least indistinguishable in the haze. I believe that a thin coat of plastic would be able to "clean up" the scuffing from buffing.

Experiment 7: CD Repair Kit Memorex CD Repair kit, purchased at store for $15. Contains a compound that fills in scratches, and another to polish the surface. I applied this to the CD that had been repaired. It filled in the scratch a little bit, but not so much that it could not be detected if you're looking for it. The polishing spray made the surface more reflective, thus making it harder to see the scuffing.

Planned experiments Please, add any experiments you'd like to suggest by clicking on EditLinks? at the bottom of the page, and adding your comments.' Here are some ideas for experiments.

Ways to grind down the surface to eliminate scratches: Vary the abrasiveness of the tripoli. Use a wet solution of talc. Use a wet soluton of talc and alcohol.

Ways to remove the scuffing: Furniture wax. Car wax. Future acrylic floor polish. Glass polish. Miscellaneous solvents, to melt the surface. Rain X (acrylic glass polish). Denatured alcohol. Hair polish/shine enhancer (like Frizz Ease).

Notes: The best way to test the scratching is with your fingernail. The toothpase, eraser, and buffing wheel produced tangibly different scuffing of the surface.

I tried a lighter flame on the scuffing, and it smoothed it out, but didn't have much visual effect.

The polycarbonate used to make CDs is not a regular plastic. That is, it is not soft, like vinyl, and probably will fail to dissolve in my solvent experiments.

The scuffing on the surface doesn't seem to affect audio CDs. I don't know if this is true for data CDs.