Mark Rand wrote:
I've got a few projects that could usefully start from aluminium castings. I
also currently have 120 ex-server hard disks.

When stripped of all the steel, copper, magnets and electronics the hard disks
yield 12oz-1lb of powder coated or cobalt sputtered aluminium. Probably in
three different alloys (case, platters and HP/Compaq mounting brackets)

The question is, does the team think that these will be a good source of
casting stock once they've been melted down, de-drossed and cast into ingots?

I suspect that they might be made from "white metal"
rather than AL. Can't prove it, but trying to TIG
weld a couple WD castings together with AL filler gave
pretty sloppy results even with meticulous prep.