# Hdd platters



## patnor1011 (Apr 24, 2016)

I do have couple hundred of them and they slowly starting to irritate me. I do have idea of what to do with platter from desktop hdd but I have no clue what to do with laptop hdd platters. They are made from glass so cant be used for everything you may use aluminium one. Do anyone have any idea what exciting or useful can be made from them? What can I use them for?


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## g_axelsson (Apr 25, 2016)

No idea, but a trick to separate aluminum from glass platters without breaking the glass is to use a powerful magnet from a hard drive and eddy currents.

Hold the platter at 45 degrees angle and let the magnet slide over the surface. On the aluminum platter it slides slowly while on a glass platter it slides off quickly.
You could also hold the platter horizontally and shake it left and right, the eddy currents in the aluminum will grab onto it and the magnet will follow the platter at a certain degree, on the glass platter the magnet will remain almost stationary.

There are no general rule that only laptop disks use glass. I got a large bunch of 3.5" HDD platters made of glass in the workshop. About half of the last batch of server disks I scrapped was made of glass.

I'm planning of treating the glass platters in AR just to see if I can detect any platinum in the end, that's my best idea.

Göran


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## solar_plasma (Apr 25, 2016)

Since they have an equal density maybe they can be sorted by their different heat capacity using a cheap infrared thermometer. That's a big "maybe" with many variables...but worth trying I think. What does the physicist say, Göran?


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## g_axelsson (Apr 25, 2016)

solar_plasma said:


> Since they have an equal density maybe they can be sorted by their different heat capacity using a cheap infrared thermometer. That's a big "maybe" with many variables...but worth trying I think. What does the physicist say, Göran?


A thermometer measures temperature, not heat capacity. So if they have been sitting in a room for a while it could not detect any major differences.
But heat conductivity differs, pick up a aluminum platter and it feels colder than a glass one, just because the heat from your hand is conducted away a lot faster by aluminum than by glass. I just tested it and it works... well, maybe not in a hot place, the closer ambient temperature is to our body temperature the harder to feel a difference.

Göran


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## patnor1011 (Apr 25, 2016)

That, they are different on touch and also do have different sound. I just put one on screwdriver through hole and hit it with another piece of metal. Or let them fall on table (from small high to not break glass one's). 
I can easily sort them I was just wondering what to do with glass type.

I will try your suggestion with magnet, I got few hundred of them too. I do have shelf rack in garage which is made from metal. I stuck magnets on it and they hold quite a lot of my tools, I finally do have most of them on one place and on my eyes. I do not need to look for them in various places now


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## solar_plasma (Apr 25, 2016)

g_axelsson said:


> solar_plasma said:
> 
> 
> > Since they have an equal density maybe they can be sorted by their different heat capacity using a cheap infrared thermometer. That's a big "maybe" with many variables...but worth trying I think. What does the physicist say, Göran?
> ...


 yes ofcourse..... I would have put them into boiling water first and watched the falling temperature....or from a freezer an watched the temperature rising

More heat capacity would mean slower falling or rising...well, in my simple mind. Problem might be different thermal conductivity, but nevertheless there should be an observable difference between glass and aluminium. 

More advanced you would use an isolated vessel with a known amount of water, measuring the temperature before an after putting the platter into the water.

But if it also works by feeling the thermal conductivity with your hands, this should be the easiest way.


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## lanfear (Apr 25, 2016)

If you know anyone that is in to metalldetecting they will have a pinpointer. I am shure you could seperate them with that. It will probably make a faint sound on the glass platter because of the platinum, but it will be easy to differentiate the two.

Jon


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## patnor1011 (Apr 25, 2016)

:twisted: And there you go...
As it happens I do have Minelab explorer II and I also do have pinpoint probe. My bad that I never thought it could be used this way. Sometimes the best solution is right under your nose. :mrgreen: 
Thanks for your suggestion, that will shorten separation time. I am going to test your theory with my pinpoint probe, I may need to change battery as I did not used it for like 3-4 years.

I may try to make custom geek/nerd mirror out of them. They do have mirror like surface so if I try to glue like 100 of them in some frame it may look interesting.


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## patnor1011 (Apr 25, 2016)

Just tested pinpoint probe. Works like charm. On very close proximity it detect metals on surface of glass hdd platter but using probe on aluminium and glass hdd platter is fail proof as it detect aluminium one from distance of couple centimeters. It all also depend on sensitivity you set on your probe I set it up so it detected metal on glass one only when few milimeters away but also you can set it to lower threshold when it will simply exclude small amount of metal on glass hdd foil and give signal on aluminium one only.


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