Destroy coating on hard drive platters?
lee...@my-deja.com
and now want to ensure that the platters are "cleaned of
any data". (It was quicker to take apart the drives using
a power screwdriver and proper torx bit than connecting
the drives up to a system and erasing them).
Of course, I could simply beat the platters up with
a hammer and that should be good enough to keep most
people from recovering the data (except maybe some govt.
agency or ambitious sci-nerd type), but I was wondering
if I wanted to get rid of the oxide coating what would
be the best chemical method?
I don't know the composition of the coating other than
it is quite silvery and only faintly brown - if it were
mostly FeO (Fe2O3?) it would be more reddish, no? So I'm
assuming that it's (maybe) CrO2?
My inorganic chem knowlege from high school is pretty
dim, so I'm counting on the sci.chem denziens to have
a good answer.
I guess throwing the platters into a fire would mess
up the magnetics pretty well too...
Thanks!
Bob
>I have a number of old hard PC drives that I've taken apart
>and now want to ensure that the platters are "cleaned of
>any data". (It was quicker to take apart the drives using
>a power screwdriver and proper torx bit than connecting
>the drives up to a system and erasing them).
>
>Of course, I could simply beat the platters up with
>a hammer and that should be good enough to keep most
>people from recovering the data (except maybe some govt.
>agency or ambitious sci-nerd type), but I was wondering
>if I wanted to get rid of the oxide coating what would
>be the best chemical method?
>
Computer recycling places around here say that they destroy the hard
drive data magnetically. Easier.
bob
Uncle Al
Propane torch or fire. Heat above the Curie point. "Erasing" a file
only removes its arrow not its content. "Washing" a drive is no proof
against expert recovery. One need only scan the edges of each track.
Minute imperfections in head positioning spill data just outside
nominal read/write width. Physical shape alteration won't work -
laser scanning and the Faraday effect to read the magnetization.
Heat it up, burn it off, then sand it clean.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
Scrim
recover what I hoped would be high optical quality glass. After trying
various caustics and acids I resorted to a few days soaking in Aqua Regia.
This got most of it off, but even then a number of islands of coating
remained untouched!
By the way, the 'glass' was quite remarkable stuff, taking a surprisingly
large amount of bending force to shatter it.
Scrim
<lee...@my-deja.com> wrote in message
news:1110608802.1...@g14g2000cwa.googlegroups.com...
Bernhard Kuemel
> I tried stripping the coating from some fairly modern glass platters to
> recover what I hoped would be high optical quality glass. After trying
> various caustics and acids I resorted to a few days soaking in Aqua Regia.
> This got most of it off, but even then a number of islands of coating
> remained untouched!
Assuming that the layer is magnetic particles bonded with some
organic resign 60 C fuming (>98%) nitric acid may be successful.
This method is used to dissolve the epoxy covering chips when
hacking smart cards:
But simple heating is probably the best solution.
Bernhard
Scrim
"Bernhard Kuemel" <spam...@bksys.at> wrote in message
news:4235b8fc$1...@e-post.inode.at...
AFAIK The coatings on hard disk platters are evaported on in the same way
anti-reflective layers are applied to optical components. I'm certain that
no organic binders are involved.
Scrim
Steve Turner
1) Tape platters together into a disk.
2) Send 3-5 .357 hollowpoints into the mass.
2a) If mass is very thick, substitute .308 FMJ or similar.
Use eye and hearing protection, etc etc.
Steve Turner
Uncle Al
No good. Data can be retrieved by the Faraday effect in a scanned
laser beam. The platter surface is typically a diamond-like carbon
topcoat. First you furnace the platters to heat above the Curie point
and burn off the head crash protection. Then you cool and sand off
the surface on both sides.
Hollow points are stupid. Use solid brass or AP rounds to puncture.
Stupid idea anyway, even with a ball peen hammer.
dlzc1 D:cox T:net@nospam.com N:dlzc D:aol T:com (dlzc)
"Uncle Al" <Uncl...@hate.spam.net> wrote in message
news:423627FE...@hate.spam.net...
I've got a better solution. Substitute the hard drives for the
"5 pound sledge" used to take magma samples. Leave off the
retrieval cable. And you'd only have to go to Hawaii to
accomplish it.
David A. Smith
Mark Thorson
> AFAIK The coatings on hard disk platters are evaported on in the
> same way anti-reflective layers are applied to optical components.
> I'm certain that no organic binders are involved.
I'm certain that there is more than just magnetic materials
applied to the disks. There is a top coat, and surfactants
on top of the top coat. The surfactants are typically
fluorocarbons, which would produce hazardous compounds
if incinerated (but probably in amounts too small to be
harmful, unless you're a bird).
At least, this is true if the head actually lands on the disk
(so-called Winchester disk drives) when it is powered down.
If the head is retracted (as in some disk drives), they might
have eliminated these layers.
Dirk Bruere at Neopax
Thermite
--
Dirk
The Consensus:-
The political party for the new millenium
http://www.theconsensus.org
Octa Ex
On Fri, 18 Mar 2005 01:59:02 +0000, Dirk Bruere at Neopax
<di...@neopax.com> etched in cyberspace:
X X
X
X X
Steve Turner
wrote:
>No good. Data can be retrieved by the Faraday effect in a scanned
>laser beam. The platter surface is typically a diamond-like carbon
>topcoat. First you furnace the platters to heat above the Curie point
>and burn off the head crash protection. Then you cool and sand off
>the surface on both sides.
I'm not particularly worried, Faraday Effect or no Faraday Effect. If
you saw the remains of the disk platters you'd know what I mean.
>Hollow points are stupid. Use solid brass or AP rounds to puncture.
>Stupid idea anyway, even with a ball peen hammer.
AP rounds are unecessary unless you're talking about large numbers of
platters. The advantage of hollowpoint are the massive deformation
and delamination they cause. AP would tend to punch a clean hole.
Steve Turner