Warning: Re: etching aluminum?

[KA4HJH]

In summer chemistry class they told us that a mixture of hydrochloric acid
and nitric acid (aka Aqua Regia) will dissolve gold, too (we never saw it
demonstrated). It should be just as dangerous as the concoction under
discussion and it gives off chlorine fumes to boot. I used to feel sick
every day after four hours in the lab. Takes stains off glassware like
magic, though.

Terry Bowman, KA4HJH