# I beg opinions re specific platters and monolithic caps.



## Redders (Dec 1, 2007)

Over the next few weeks I will be breaking down eighteen racks worth of IBM mid range rs6000 gear. There looks to be around five hundred ibm disks which are 4.5, 9, 18 and 36GB. I have cracked open an 18 and a 32. The 18 has five platters which are glass with a silver mirror-like coating. The 36's are the same model (COMP-950) but have ten platters, the thick door-stopper type drives which I don't think would be sellable for re-use.

I smashed the fifteen platters and ground them up a bit then put half in with HCl and the other half in with aqua. That was yesterday. I will follow up later.

I am seeking LaserSteve and other's opinions here.... do you think it is worth my time harvesting platters from say 400 hdds? All the research that I can see on the site seems to suggest that nobody has really found this a fulfilling thing to do. Maybe these glass platters are easier than the aluminium ones because the platter can be crushed down and allow an acid to work on separating the coating from the grains of glass. What do you think the coating is? I will add a picture very soon.

Also, there are some power supplies which have capacitors which are blue, cylindrical, two inches long by 0.75inch dia. I assume that they are the monolithic capacitors of which Steve makes mention. I could harvest, maybe, 500 of these. Is it possible for a newbie to recover pt from this lot. I will add a picture to this thread later. Please respond if you have any views on these two possible sources.

cheers m'dears


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## lazersteve (Dec 1, 2007)

Redders,

The blue caps sound like electrolytics to me not monolithics.

You should do a quick scratch and dissolve test on one of the platters before you jump into processing all the HDD platters. Throughly scratch a small 1/2" area from the surface of the disk and put three drops of HCl followed by 1 drop of 70% HNO3 on the loose foils. Heat the spot for 15 seconds with a heat gun and test with stannous for Pt (brown color).

Post some photos of the RS6000 boards and I may be able to help you id some of the juicier parts.

Steve


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## junkelly (Dec 2, 2007)

Redders said:


> do you think it is worth my time harvesting platters from say 400 hdds?



400 Hard drives = 400 - 800 rare earth magnets. You'll have to check, but I've seen these sell in lots of 3+ on eBay for $1 - $2 each...

As for platinum, I have no idea...

-junkelly


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## Noxx (Dec 2, 2007)

Speaking of magnets, how do you remove them from the plate they are glued to ? Each time I try, I break the magnet...


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## jimdoc (Dec 2, 2007)

Noxx,
I just leave them on the backing plate.
That gives you a way to mount them
for different uses. I have broke a few
also before I just stopped trying to 
remove them from the plate.


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## loco (Dec 3, 2007)

they are just glued or epoxied right? anyone tried heating them up when trying to pop them off? just an idea.


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## Noxx (Dec 3, 2007)

I taugh about it and it's a good idea... But I haven't tried yet since I have no more lab  

Maybe I'll try when my parents are away


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## Anonymous (Dec 4, 2007)

Hi folks,

First time posting but this is one I can answer.

Just get 2 pairs of vice grips or other pliers or wrenchs that will allow you to gently twist the metal plate.

You should be able to get a corner of the magnet a small distance away from the plate.

Then just take a pocket knife and slide it across the back of the magnet. You may cut through the magnet coating but you should have decent success with the magnets.

I've processed a bunch this way.

-Mark


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## aflacglobal (Dec 4, 2007)

Welcome to the forum Mark.


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## Redders (Dec 5, 2007)

I scraped the minute rectangular read/write head from each arm that steps out onto the platters (nine platters). They were brittle, I crushed them with a hammer. The remnants could have sat on a shirt button. I put them in a test tube and added twelve drops of AR. The solution was a beautiful golden colour.

See the stannous chloride tests? What does anyone see here? thanks.

also at the pivot shaft of the head assembly there was a one inch board which has excellent quality gold wires (but very fine).

any comments?


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## lazersteve (Dec 5, 2007)

Redders,

The test spots are still fresh so it's difficult to determine if the brown color is Pt (stays brown) or Pd (turns from brown to blue green after a short time).

The spots also appear to display a purple tint so gold may also be in the solution. If the gold is in high enough concentration it may also appear dark brown to black. 

Try diluting the liquid in the test tube and retest. If you have DMG you can confirm Pd.

Looks promising.

Steve


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## Redders (Dec 5, 2007)

What about ths, Steve. Overnight color (?) change......


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## lazersteve (Dec 5, 2007)

Redders,

Looks like gold.

That doesn't mean you don't have any PGMs, the color changes they make disappear after they dry overnight. You should precipitate the gold and retest the pregnant solution.

Pt and Pd will both initally show brown, then after about thirty seconds or so, Pd will turn blue green, Pt will stay brownish. Both these colors disappear after drying overnight.


Here's positive a Pd swab after 10 seconds:

[img:513:390]http://www.goldrecovery.us/images/pospd.jpg[/img]

Steve


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## badastro (Dec 5, 2007)

Don't heat the magnets if you intend to keep them as magnets. Heating will demagnetize them if you heat it beyond the currie point.


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## Bernie Foley (Dec 5, 2008)

Hi friends,
from what i read these magnets start to lose it at 180'F. I think that is the max service temp...use a ceramic magnet for higher temps....I sure
spoils some of the things i wanted to do with them!.............Bernie


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## silversaddle1 (Dec 5, 2008)

Man, I just throw all those magnets into the scrap box. 1000's of them infact. I tell you what, I scrapped some big Hitachi drives that had 15 platters in each one. You want to talk about magnets, those were the meanest ones I've ever seen!


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## Harvester3 (Dec 5, 2008)

Man yeah, some of those old scsi drives have magnets that'll draw blood. (I speak from personal experience [:~)


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