Jaap, the word "weakest" in your response can be interpreted as meaning the
material that is structurally less strong. Comparing aluminium/aluminum to
steel, yes, it is structurally weaker. But what causes the
aluminium/aluminum to corrode rather than the steel is that it is higher on
the galvanic scale than steel and therefore more anodic. When two metals
are in contact with each other in the presence of an electrolyte (like
moisture), the more anodic will corrode first.
Lead is structurally weaker than aluminum, but in an aluminum/lead joint,
the aluminum is still more anodic and will corrode first.
And "rust" is just a special term for corrosion on iron and steel.
Havelock, NC USA
From: firstname.lastname@example.org [mailto:email@example.com]
On Behalf Of Jaap Aeckerlin
Sent: Sunday, October 17, 2010 8:28 AM
To: john spaur; Healey forum
Subject: Re: [Healeys] Healeys] Boot pan to shroud
John, sorry, but I have to disagree. Aluminium (sorry - aluminum) is the
weakest of the two mating materials and therefore the main problem with this
joint will be the aluminum which will suffer from electrolytic(galvanic)
corrosion. A rust film will form on the steel, but it's the aluminum that
will disappear much faster than the steel. Therefore corrosion is the
problem, not rust.
Jack Aeckerlin, The Netherlands
1964 BJ8 29432
2010/10/16 john spaur <firstname.lastname@example.org>
> Rust is the problem with this joint, not corrosion!
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