Author Topic: Hard Drive Platters - Any Problems With Melting?  (Read 1302 times)

Offline Pete W.

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Hard Drive Platters - Any Problems With Melting?
« on: May 13, 2016, 08:02:47 AM »
Hi there, all,

(especially those experienced in home foundrywork)

I've accumulated quite a lot of computer hard drives and have been 'processing' them ready for offering them to my local scrap metal dealer.

The actual disks (aka 'platters') are aluminium alloy but coated with the magnetic material that actually stores the 0s and 1s.  As far as I know that coating is very thin so its effect on the weight is negligible.

What experience have Modders had with melting such HD platters?  Does the magnetic coating cause any problems?   :scratch:   :scratch:   :scratch: 

Can I, with a clear conscience, include these platters with the rest of my scrap aluminium offering on the basis that the coating is chemically benign?
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest change-note!

Offline RotarySMP

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Re: Hard Drive Platters - Any Problems With Melting?
« Reply #1 on: May 13, 2016, 08:38:37 AM »
I only melted the HD frames, and binned the platter. They are thin with larger surface area, so they are just going to produce 60% slag anyway.

Mark

Online awemawson

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Re: Hard Drive Platters - Any Problems With Melting?
« Reply #2 on: May 13, 2016, 09:10:09 AM »
That slag effect can be avoided by plunging them below the surface of a crucible of aluminium, thus excluding the oxygen.
Andrew Mawson
East Sussex

Offline Eugene

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Re: Hard Drive Platters - Any Problems With Melting?
« Reply #3 on: May 13, 2016, 11:53:02 AM »
The coating is a deposit of electroless nickel plate.

It will have a melting point well above that of the Al base. It's also pretty chemically inert, much more so than ordinary nickel by virtue of the alloying phosphorous.

Really it's a case of suck it and see, but I wouldn't be too hopeful.

Eug

Offline Will_D

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Re: Hard Drive Platters - Any Problems With Melting?
« Reply #4 on: May 14, 2016, 06:50:42 PM »
The disk platters make great mirrors!
Engineer and Chemist to the NHC.ie
http://www.nationalhomebrewclub.ie/forum/

Offline Pete W.

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Re: Hard Drive Platters - Any Problems With Melting?
« Reply #5 on: May 15, 2016, 04:50:48 AM »
Hi there, all,

I feel I should emphasise that I'm not contemplating home foundrywork - that's one of my retirement projects I've had to cull now I've commenced my 80th orbit.  My concern was whether I could legitimately offer the platters to the scrap metal dealer as aluminium without any qualifiers.

An aside regarding 'recycling' of old computer hard drives: we offered some NeFeB magnets on eBay.  One buyer was a biker who wanted stronger magnets for his tank-bag.  He contacted us later to say how pleased he was, his tank-bag now stayed firmly attached to his tank at 'about a ton'!!

We have a 70 MPH limit so I'm left wondering what sort of a rolling road also simulates slip-stream?   :ddb:   :lol:   :ddb:   :lol:   :ddb:   :lol: 
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest change-note!

Offline DMIOM

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Re: Hard Drive Platters - Any Problems With Melting?
« Reply #6 on: May 15, 2016, 06:58:23 AM »
The disk platters make great mirrors!

or a heliograph?

in fact, how about a CNC-controlled heliograph? - feed it with almanac data, a good clock, your lat&long and receiver's lat&long, and a message text, and get it to flash the message in morse?

 :proj:

Dave

Online awemawson

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Re: Hard Drive Platters - Any Problems With Melting?
« Reply #7 on: May 15, 2016, 08:26:34 AM »
Hang them on strings over your Runner Beans to scare the birds off  :clap:
Andrew Mawson
East Sussex

Offline Pete W.

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Re: Hard Drive Platters - Any Problems With Melting?
« Reply #8 on: May 15, 2016, 09:42:46 AM »
First of all:  For 'NeFeB', please read 'NdFeB'!!!!
Andrew, I've got enough platters to scare the birds off all the runner beans South of that 'line from Bristol to the Wash'!!   :lol:   :lol:   :lol: 

I've even got four that measure 5" diameter.  They stored a whole 20 MB per platter in 1989!
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest change-note!

Offline sparky961

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Re: Hard Drive Platters - Any Problems With Melting?
« Reply #9 on: May 15, 2016, 11:59:31 AM »
A few years back I took a propane torch to one, just to see what would happen.  I was surprised when the edge of it started to droop and appear as though there were a liquid in a bag of some sort.  I quickly discovered what has already been said here - that there's aluminum inside and a plating on the outside.  Pretty easy to melt, but not sure what sort of alloy is inside.

I wonder if due to the plating "skin" the oxidation effect while melting would be reduced.  You could possibly melt inside the skin then dump the liquid into a container with other liquid.

Metal recyclers tend to greatly favour (and pay more for) metals of one type rather than anything mixed.  Scrap aluminum doesn't go for much though.