[Fot] Aluminum Radiators and Electrolysis

[John Herrera]

> > there isn't much difference between zinc and aluminum with respect to
> > the galvanic series, so I suspect that a sacrificial zinc annode would
> > not be very effective.
>
>Quite possible. The vintage Ferrari guys (with mostly aluminum blocks but 
>brass
>radiators) use magnesium alloys for the sacrificial anode.

Yes, it goes like this from most anodic (least noble) at the top to most 
cathodic (most noble) towards the bottom:

Magnesium / Magnesium alloys
Zinc
Aluminum1100
Cadmium
Aluminum 2024-T4
Steel or Iron / Cast Iron

So magnesium is more anodic than zinc, but only by one place. Both are 
anodic to cast iron. Aluminum is in between. 1100 aluminum is pure and 2024 
is an alloy, but I forget with what.

John