Welcome to Boardsort™ - Learn - Sell - Profit -

Does anyone know what the coating on these platters is? The standard modern ones are on the right/ bottom depending on the picture orientation.

Thank you!

Silver coloured platters from 3.5” or smaller drives tend to be a platinum alloy.
The darker the platter the more likely it is to be glass. Glass platters tend to be popular in very high speed drives because the expand linearly in the direction of rotation compared to aluminium that cones slightly like plastic discs do.

Gold ones are self explanatory.

5.25” discs have a slightly thicker layer than 3.5”. They’re thicker than 8” platters too. But nowhere near as thick as 12” and 22” platters. For scientific reasons that belong in another post.

Do keep in mind that we’re talking negligible refining amounts. The thickness is less than mils or ū counts. Usually counted in atomic layers at around 5-7.

The only way refining platters of any size is profitable is reverse electroplating in very large amounts in very fast environments.

Chris sorts them as part of the practice.
Most yards will buy them as aluminium can (alloy) rate if they can sort them and breakage if not.

_________________
42 6F 61 72 64 73 6F 72 74 2E 63 6F 6D

I would call around and inquire.
One of the local yards here buys them as "New Aluminum" which is the same rate as Aluminum extrusion: .44/lb

Exactly:

_________________
42 6F 61 72 64 73 6F 72 74 2E 63 6F 6D

As I remember my yard baught platters as clip which is currently 22 cents a pound.

Thank you!

For a slightly expanded explanation:....
Gold platters are almost exclusive to 5.25” platters and 22” canisters.

These have a layer multiple times as thick, or much wider diameter, respectively.
Which is why i mentioned some time ago to keep an eye out.
3-5 platters (5.25) aren’t worth the trouble to any recycler.

If you come across a 22” spindle sell that mofo on ebay.
I’ll pay $100 instant PayPal, zen, or crypto to anyone who has a 5 platters or higher disk 22” cartridge.
Honestly though there’s a slight increase over platters rate for gold 525 and 22 platters because they required a thicker coating.

_________________
42 6F 61 72 64 73 6F 72 74 2E 63 6F 6D

Got any sample pictures?

No. Which is why I’d pay for a single platter spindle. I have 20” and 24” platters from DEC and IBM but 22” is one of the disk formats I’m missing

_________________
42 6F 61 72 64 73 6F 72 74 2E 63 6F 6D

They average around $50 or so when they do appear. I need one to complete my collection.

_________________
42 6F 61 72 64 73 6F 72 74 2E 63 6F 6D