On Wed, 22 Jan 2020 09:00:10 -0500, Bob Engelhardt
wrote:

On 1/21/2020 12:32 PM, Clare Snyder wrote:
... For zinc you can use 2
teaspoons salt/1 teaspoon copper sulphate/1 cup water solution. ...

How about muriatic/hydrochloric acid: zinc fizzes, aluminum does not?
That would work too.