Monday, March 25, 2013

Flattening a Warped CD

I recently picked up a copy of Donald Fagen's new album Sunken Condos from my local music purveyor. This album comes in a cardboard folder instead of a plastic case. The problem arose when the shopkeeper stuffed it into one of those plastic shells that was designed to replace the CD longbox, which in turn was designed to be easily fit into existing record store bins for holding 33-1/3 RPM long-playing records. And so the old technology lingers.

He managed to stuff the box into the holder, but in the process it was kind of crumpled and bent. I was a little dubious buying it, but I was able to feel that the CD was not actually broken, so I thought it would probably be fine. CDs are nearly indestructible, although they can fail from age or oxidation or, or course, severe scratching. I knew it was possible to chip them, and even shatter them, but it hadn't occured to me that if you put one in a slightly bent position and left it there for a while, it would behave like a vinyl record and warp a little. If you laid this CD on a flat surface, it had a very slight "dishing" in one direction -- it would wobble just a bit like a see-saw, across one axis. When I say "just a bit," I mean the edges that wouldn't lie flat were probably sticking up about 1/8" above the tabletop.

So I had a CD that would play fine in the car, but not in any of my computers. The car CD player must have more tolerance for vibration. The CD player has to focus a laser below the surface of the spinning disc, and if the distance between the laser and the data layer is constantly changing, it might not be able to accommodate fast enough to decode the data stream.

I did some searching online and read a couple of pieces of advice; some folks claimed that had successfully flattened a CD with a heat gun. I have a heat gun for sealing plastic on windows, but I decided that was probably too much heat. Leaving the disc stuck for a couple of nights between the pages of a heavy book, with more books stuck on top, did not improve it at all.

What I finally tried was cutting up some clean, thin cardboard (from a box that held pastries) into squares a little bigger than a CD case. I laid the CD on the brown side of a square of this cardboard on my kitchen counter, then stacked three more squares on top (brown side towards the disc). Kraft paper would probably work fine too -- my thinking here was that I didn't want any kind of coating on the paper that might stick to the disc.

Then I heated a tea-kettle full of water on the stove. After it came to a boil, I let it cool for two or three minutes, and then sat it on top of the stack. My thinking was that the teakettle would be at about 180 degrees F at this point, but the layers of thin cardboard would slow down the heat transfer into the CD. I wanted the CD to get up to maybe 120 degrees F. After letting it sit for a few minutes I took the stack apart. I didn't use a thermometer but the CD felt to me like it was about the right temperature. I flipped the CD over, and put the stack back together again to sit like that for a few more minutes. Then, I took the kettle away and let it cool down for a few minutes.

I was slightly surprised to find that this actually worked like a charm.

If you try it, remember that I offer no guarantees. You might wind up ruining your disc. If this does make it readable, I would recommend making a lossless backup for your music library as soon as you can. CDs are supposed to have an airtight seal between the two plastic layers to prevent oxidation of the aluminum data layer inside. If the disc is no longer airtight after this treatment, it will gradually degrade as some of the other CDs in my collection have, over the years. Good luck! Leave a comment if this actually works for you. If it ruins your disc completely -- well, don't say I didn't warn you!

P.S.: oh, and how's the album? Unfortunately, Sunken Condos is disappointing. I think The Nightfly is just a terrific album. I really like Kamakiriad. The abstract, semi-science-fiction premises and intriguing lyrics of tracks like "Snowbound" totally seduced me when it came out. I was a little less excited by Morph the Cat, although there are some enjoyable moments. This one just seems a little flat by comparison. There are a few decent songs, but many of them drag -- not enough interesting riffs, not enough ear candy, not enough of a live feel. I wish I liked it better. Maybe it will seem better after a few more listens, but I doubt it. Too bad!


Suzie C. said...

Thank you SOOO much for your post!!
I had a CD that had accompaniment music for violin I'd ordered from a company, and when I got it, it was warped--would play in a boom box, but not in my computer. At a cost of $4.50, it wasn't worth shipping it back (they wouldn't pay for return shipping, although they would have given a refund). I simply Googled 'How to straighten a warped CD', and up came your blog post.
I tried it just now, and I had to keep putting the tea kettle back on a few times, but it finally worked! I'm not trusting that it will work again in the future, but I'm importing the music into iTumes right now, then will back up the music several ways.
THANK you SO SO much for this tip….it saved me from the hassle of buying a new CD, as well as the pain of sending the warped one back and going thru the online return process!

Paul R. Potts said...

Susie, I'm very glad to hear it!

Liz S said...


Tried out your suggestion! Worked perfectly. I put it under a flat-based saucepan full of boiling water with a few layers of thick brown paper on each side and left it for about 1/2 hour each side (a few minutes did nothing). Now I've ripped it onto the computer and it took no time at all!

Thank you!

Paul R. Potts said...

That's great to hear that it worked for someone else!

Unknown said...

Thanks, this (eventually) worked for me on two audio CDs.

After two failed attempts, I had success with the CD on a pieced of smooth granite, wrapped in (baking) parchment paper, under 1.5 liters of water heated to 200 degrees Fahrenheit in a flat-bottomed saucepan, and left for more than two hours.

I used a single piece of (baking) parchment paper above and below the disk with no other insulation.

I didn't realize this at first, but the surfaces that you press the CD between have to be nearly perfectly flat. The bottom of the first saucepan that I used had a slight warp, which obviously defeated the purpose of using it to flatten the CD.

For a particularly obstinate CD, I had to heat it, then press it between two 12"x12" squares of granite (the kind that you use to make a kitchen counter, and which can be bought from a hardware store for 99 cents each), then set a 15 pound weight on top and left it overnight. This finally got the CD so that it would play in my DVD player and in my car CD player; but I could never rip it to MP3 (or even play it) in either of the CPU CDRoms that I tried it in.

Thanks again for the very useful post!

EdAllegro said...

It worked for me. Thanks for porting.

Bob said...

What worked for me was far simpler. Very carefully and SLOWLY heated the disc with a heat gun, inserted it into a rounded-bottom anti-stat inner sleeve (the type that come in Japan mini-sleeve CD's) , then quickly put it into a thick book and added an additional heavy weight on top. Left it that way to cool for an hour,. Disc was completely flat again.