Types of corrosion on computers

[Santo Nucifora]

I've seen this a few times.  I never knew exactly what it was but it
usually comes off but there is staining left over.  Here are a couple of
explanations from Google.

*White rust* is a *white* powdery deposit formed from a natural *corrosion*
process that can occur on any new zinc coated steel product. It is damaging
to the appearance of the steel, not to mention to the anti-*corrosion*
layer of zinc that protects the body of the steel.

Galvanized *metals* also *rust*, but they do so at a slow rate unless the
galvanized coating has been damaged. Brass, silver, and bronze tarnish as
they interact with the atmosphere. Aluminum oxidizes into a *white powder*,
although the *powder* binds chemically to the *metal* beneath, blocking
further *corrosion*.

On Fri, Dec 8, 2017 at 6:09 PM, Adrian Stoness via cctalk <
cctalk at classiccmp.org> wrote:

> water get sprayed on it?
>
>
> On Fri, Dec 8, 2017 at 5:06 PM, dwight via cctalk <cctalk at classiccmp.org>
> wrote:
>
> > Could be the zinc plating?
> >
> > Dwight
> >
> >
> > ________________________________
> > From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Sam O'nella
> via
> > cctalk <cctalk at classiccmp.org>
> > Sent: Friday, December 8, 2017 2:46:40 PM
> > To: General Discussion: On-Topic and Off-Topic Posts
> > Subject: Types of corrosion on computers
> >
> > I've seen rust and dust, but there's an old vaxstation II at Goodwill
> > Computers in Austin right now (very cheap, anyone welcome to buy it and
> get
> > it off my mind) but as most things, I checked out the back and see some
> > circles of white corrosion on the back where the cards? are contacting
> the
> > case.
> >
> > I don't really have room or time but I don't own anything that uses QBUS
> or
> > is almost related to some of the neat iron some of you all collect (I've
> > mostly collected way too many home computer history items).
> >
> > Anyway, what is that type of white corrosion on metal?  Would one
> probably
> > assume this means any bus would be corroded and this wouldn't be a
> computer
> > for the faint of heart hobbyist? I've only seen that maybe from batteries
> > but it's in an unusual place and pattern (I think).
> >
>