Isopropyl alcohol and CD(R) crazing?

Blank Media
#1

Someone who works in the plastics industry told me that isopropyl alcohol dries out the petrochemicals in polycarbonate, thus predisposing to crazing.

What do you guys think of this CD (CD-R?) cleaning protocol:

  1. intial clean with dish soap (someone recomended Ivory liquid) and warm water.
  2. quick rinse (30 seconds?) of the read side only with a dilute (10%) solution of isopropyl alcohol to remove any subtle residue.
  3. final rinse with distilled water (my faucet has a Pur water filter; do you think this will work equally well?).
  4. no further exposures to isopropyl alcohol.

Do you think I will still run a significant risk of crazing? Also, would this crazing, if present, be visible if I look at the CD surface under a strong light?

Any insights would be greatly appreciated!

#2

At 10% you will probably do no harm, but it’s really not necessary.

#3

Is this “someone who works in the plastics industry” a reliable, knowledgeable person? After all, many “facts” are circulated by people who hear them from someone who sounds convincing and appears to know what they’re talking about. Hell, I’ve been guilty myself of taking statements at face value, only to find later that it’s crap and the person really doesn’t have a clue what they’re talking about, even though it all sounded quite logical at the time!

Just because they work in the industry doesn’t necessarily mean they’re right.

I would be very interested if anyone can confirm this possible effect of Iso-propyl, 'cos I’ve been using it for years and would like to know if I’ve sentenced my discs to a slow death :eek: .

I use the small sachets used to clean optic fibre cable ends, but only use them to remove greasy fingerprints - bear in mind that this stuff evaporates within seconds, so it’s not as if you’re soaking the discs. (You’re not, I hope :wink: ).

So, can anyone enlighten us further?

#4

I personally don’t know that person, but he sounds like he knows what he is talking about.

Someone else said that crazed CDs can be much more brittle than non-crazed CDs, will probably play well at regular speeds, but risk the potential of shattering when played back at high speed.

The crazing is apparently a fine network of cracks or spiderwebbing on the treated side of a CD. Someone else suggested using a jeweler’s lens to see the cracks. I have put some CDs under a very strong light and still can’t see any evidence of crazing yet. My guess is that the cumulative risk of crazing would be proportional to cumative isopropyl alcohol exposure.

Hope this helps. Maybe others have some additional input.

#5

well all i can say is, why not leave one of the blank cds soaked in isopropyl alcohol for a some time…

then try breaking it… i know you have lots of cd-r that are lying around there and useless… so you won’ t mind testing it…

#6

When the CDs were introduced (1983), the music companies gave hints in the booklets, how to handle CDs. Many wrote, one should clean them with pure alcohol (ethanol). As ethanol is more aggressive than propanol, it should not be a problem to clean with propanol (isoprobyl alc). But recently I heard, one should not clean with alcohol, as the polycarbonate will become brittle.
I cleaned some CDs with pure ethanol and never saw a deteroriation of the polycarbonate.

#7

I saw, even TDK recommends cleaning with ethyl alcohol (written in the booklet of a TDK-Reflex:
“For thorough cleaning use a soft cloth moistened with a few drops of ethyl alcohol cleaning fluid…”
More clear in German: " Verwenden Sie … ein weiches, mit ein paar Tropfen Ethylalkohol angefeuchtetes Tuch"

I think, they know, what they write!

#8

i have dipped a fresh cd-r onto a bowl filled with “green cross alcohol” 70% isop. alcohol…

and the cd still as tough as the one who weren’t swimming… that plastic expert is sure dumb… if you ask me… what is he talking about? cd-r(s) are not germs that you can kill with alcohol…