Earthing Aluminium and other anti-corrosion matters

[Keith Coman]

FYI

The December 2012 edition of the South African Vintage and Veteran Association magazine turned the spotlight on corrosion prevention in ally engine blocks and cylinder heads.

One interesting point stressed the importance of earthing these components on account of there being a small electrolytic current being in play due to the presence of cooling water and dissimilar metals. [Solution: put in earth straps and clean their contact points annually.]

Another article went into detail about the corrosion risks associated with high calcium levels in certain regions' tap water; a contingency that the author said is not satisfactorily ameliorated by the use of ostensible silver-bullet fixes in the form of branded water additives and anti-freezes. In his case, he made specific reference to his experience of working with Lancia engines. [Solution: Use distilled or rain water instead of the garden hose where calcium is present in the mains water supply.]

Finally there was strong support for a completely synthetic cooling and corrosion-stopping product that does away with water completely.

 

[chrisyork]

All of that is very good practice in any event. Using rainwater is a particularely good recommendation. Here in the UK many of us have rainwater butts (barrels) collecting from the house roof via the gutter downpipe, so should be easy enough to achieve.

In terms of the corrosion effects, the 4 pot suffers badly from this source. The V8 seems to have almost no steel or iron in contact with the coolant to set this up. About the only thing I can think of is the water pump rotor - and you're going to have fun figuring out a way to earth that!

Chris

 

[Andries]

Agip produces a coolant for, primarily, marine used engines as Perkins, Cummins etc. I use the same in the Rover as it's especially designed for aluminium. I think, as most owners, I've seen the white deposits in the inlet manifold or thermostat housing and can only think of this as oxidized aluminium, it won't block as the spaces are too big and the corrosion process very slow but it's never bad to take precautions.. In Holland we have regions with a lot of lime in our tap water, this is much worse! It clogs up everything, washing machines, the lot.
Andries