I have been told not to work on aluminum and sterling in the same
workplace or with the same tools. Can anyone comment on this?
Some metals one might work on would, even in small quantities,
contaminate silver. and example is pewter, which is mostly tin. Small
bits on your silver, if still there when next you heat the silver to
anneal or solder, will deeply etch nasty scars or even holes right
through the silver. Lead alloys (like tin/lead solders, etc) are even
worse. But aluminum does not alloy with or mix with silver, so even a
bit of molten aluminum on the silver shouldn’t have a negative
effect. Mixing tools, etc, would of course mean your filings and
dust would not have as much silver in it as you expect when you send
it for refining, but aluminum is one white metal which probably CAN
be used on the same workbench without risk of disaster. That’s not
true with a number of others. Brass, for example, on the silver would
also etch/melt in much easier than expected (silver solder is, after
all, essentially silver mixed with brass)
In a similar vein, we’re usually told when working with platinum, to
use seperate tools and workspace if possible from when working with
gold, silver, or other lower melting metals. The dangers are indeed
there, but to be honest, with some care, you can avoid the problems.
It IS important to keep your heating/soldering surfaces clean of
other metals or bits of solder, etc. That’s where the most dangerous
risks exist. And cleaning your files, especially, is a good idea,
since a file gets used with enough force on the cutting edges that
bits of the metal already stuck in the file teeth can sometimes get
forced into the metal your filing. Not common or a major problem, but
possible, and an avoidable risk.
In general, at least in my experience, the dire statements of risk
tend to be somewhat over stated. It’s real enough sometimes (but not
really with aluminum, for the reasons already stated, it doesn’t mix
with precious metals even when melted), but with decent attention,
you can safely work with multiple metals on the same bench, with the
same tools. I think in the last 35 years or so that i’ve been working
with metals, I can probably count on one hand the number of times
I’ve had a problem with this sort of contamination, and I’m not all
THAT careful either. After all, a basic rule of soldering is that
your metal should be clean first. Just doing that attentively avoids
the majority of situations you can get in trouble.
I think I’d probably be safe in saying that if you’re working in
pewter, then perhaps you need to be more careful than usual. Tin and
lead are unusually damaging to precious metals. And if you’re working
with platinum you need to be more attentive too, and with more than
just avoiding other metals. But those tend to be special cases.
Hope that helps.