Crushed or shredded soda can for melting aluminium metal? 1

It won't matter much when it is liquid.

Crushed cans can't be washed before melting if that makes a difference.

And water can be trapped in crushed cans witch can cause steam explosion issues.
If you charge cold and melt, then crushed would be fine.
But any additions to the melt should either be shredded or crushed that have been baked well.

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P.E. Metallurgy, consulting work welcomed

Certainly water is a problem - but notice that shredding still requires a heat cycle to drive moisture out which might be remains of the contents - this moves it to likely candy-temperature problem, boiling hot isn't enough.

Steam explosions in aluminum are no joke - Here's an extreme example of water exposure: but if that happens during the melting process it can also produce a red-hot aluminum geyser.