A further interesting note -
copper plating.Use about a cup full of
Aluminium Sulphate for every 2 litres of water
always in a plastic container. Have good ventilation due to Hydrogen gas.
You can also use the same method for
copper plating the item you have cleaned of rust.
The formally rusted item is connected always to the 12V
negative electrode and
the positive 12V to the sacrificial electrode - just some steel strips.
Also - to the negative electrode attach copper wire in the solution of Aluminium Sulphate -
use multi-stranded wire.
That copper wire will dissolve in the solution in about 20 minutes creating copper ions
that will copper plate the item that is also negative.
It won't be flaky copper plate that will rub off but - high quality thick copper plating!
That will form a nice surface as for a finished item or it can also be painted over.
Note - only shiny clean areas will be copper plated.
So - where can you buy your Aluminium Sulphate from?
https://www.bunnings.com.au/hy-clor-2kg-flocculent-soft-pack_p3090210$20.85 for 2 kg.
Normal usage:
High potency granular flocculent for muddy, algae infested or severely cloudy pools.
For use in pools where the floor of the pool can no longer
be seen due to suspended particles or algae in the water.
Always use safety goggles.