Ways to *REALLY* erase a hard drive?

Just bend the platters a tiny bit.

What's on them, anyhow?

John

"Greysky" wrote in news:vVPOd.2918$ snipped-for-privacy@newssvr24.news.prodigy.net:

You must work for some sort of top-secret government agency. But spy's are everywhere in elementary school. Can't be too careful.

DaveC

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I recently had a 80 gig Maxtor hard drive die on me. Though it was still under warranty (just) I decided a much better use for it was to turn it into a show-and-tell for the local elementary school kids. I finally managed to get the cover off the thing, exposing the inner platters. Someone told me a Torx 10 would fit those crazy screws on the cover plate - they were wrong. I had to drill them off. Now, I need to know a sure fire way of wiping data off the platters for good. The machine died before I could erase it inside the computer, so far I have a bunch of 'super magnets' which I dropped directly onto the platters and let them stay there overnight. Do you think this is enough? I would like to get them as deleted as I can possibly get them, but still be able to use the drive as a demonstration device for the kids. Thanks.

Security torx probably.

Super magnets (AIUI) will not do a bulk erase od the disk. Thermite works for me.

That would be me.

2ea 520MB western digital drives. Standard office environment, drive cover removed, running DOS scandisk in a looping bat file.

First drive lasted 8 hours. Second drive lasted 4 hours.

I expect that even a simple dust cover would extend this time, and that a newer, higher capacity drive would crash sooner.

Radio shack sells a powerful one, cheap. Get the videotape eraser, not the weaker audiontape eraser.

I don't have any practical experience with this, but IIRC, there is a temperature above which magnetic materials become very free to realign their magnetic polarity. This temperature is called the Curie temperature or Curie point, I think.

So, if you heat the disk material above its Curie point in the presence of a strong magnetic field (electro-magnet, maybe?) you should effectively render the disk unreadable.

Good luck!

--Mac

Well, then bending would take care of the data recovery problem.

John

Surely the chances of it ever working again after being opened and having a few dirty fingers on the platters are negligible ? Who is ever going to try ? After you finish the show and tell, just remove or break a few chips on the controller board. This will ensure its pretty inoperable.

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Adrian Jansen           adrianjansen at internode dot on dot net
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There are various Curie points, graded from korma to vindaloo.

Paul Burke

Probably because that what it was.

--
  Keith

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be carefull, we had a drive and when we removed the cover and was in the process of messing around with it the platter just shattered into a load of shards, it was like glass. Sonds strange I know but thats exactly what it was like

Paul

temperature

Think the Magdras point is what you need.

Years ago, when reel-to-reel tape recorders were popular, there was a gadget called a bulk reel eraser. It completely wiped any information on the tapes. In essence it was just a giant electromagent that ran on AC. The fluctuating magnet field was suffiecient to totally erase the information and not leave a magnetic bias on the magnetic medium. If you can find one, you might be able to build one easily from a discarded tranformer.

Yes, and most of the screws are Torx. But they are also held in with a drop of some sort of glue to prevent their backing out. I've extracted platters from dozens of drives which I got at our town's recycling center. I do it mainly for the magnets. And the platters make neat coasters for your drinks ;-)

Al

Beware though, that the design of digital tapes, can make them much harder to erase, than the old audio tapes. I had an eraser of the type you are referring to. Had happily erased any number of audio tapes, then tried a DAT tape. It was amazingly resistant to this type of erasure (after ten minutes, it eventually became unreadable). The same is almost certainly true of the data on a hard disk.

Best Wishes

Damn, stole my favorite technique. Getting the thermite lit is the tough part - magnesium helps for that. I figure what you really need is a ceramic holder for the drive that'll keep the molten stuff in one place and turn the whole thing into a lump of slag, rather than melting straight through.

You may want to remove the drive from the PC first, too.

Scott

Remove the cover. Remove the platters and sand off the media. (DoD trick)

Like I said before, radio shack sells them. They are called video tape bulk erasers now.

I read in sci.electronics.design that Paul Burke wrote (in ) about 'Ways to *REALLY* erase a hard drive?', on Fri, 11 Feb 2005:

What about phall? Many Indian restaurants won't serve it to people they don't know, because the effects on an inexperienced eater upset the other customers. Symbol - five chilis.

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