Hi all,
There are anodes designed specifically for auto installations. They work; I
can attest to that!!
For the radiators and elbows, use the zinc/magnesium anode that JC Whitney
sells. I use one in the Tiger, as it has an alloy radiator.
The all-car units hook to the battery to provide protection, so you don't
need to dunk the car in the bathtub!!
Best,
Ray McCrary
"Speed is Life;
of course Luck and Altitude
are helpful, too."
----- Original Message -----
From: "Hermance, Jonathan" <Jonathan_Hermance@ATK.COM>
To: "'david.tinker'" <david.tinker@virgin.net>; <mg-t@autox.team.net>
Cc: <Sleuth@usa.com>
Sent: Tuesday, April 25, 2000 10:15 AM
Subject: RE: TF Restoration.
> Is There A Corrosion Expert Out There?
>
> Sacrificial anodes protect steel boat hulls in water. Without submersion
in
> water I doubt the cathodic circuit is complete enough to protect against
> corrosion caused by localized galvanic reactions in moist or temporarily
wet
> areas of a car body.
>
> The aluminum panels will protect any steel they contact from corrosion by
> sacrificing themselves. Aluminum is more active than steel. A scratch in
> the coating on an aluminum panel under a steel washer as the steel nut &
> bolt are tightened can become a focal point for corrosion if moisture is
> regularly or continuously present. The exposed aluminum around the hole
in
> the aluminum panel will transfer ions to the steel parts, loosening the
bolt
> by pitting of the aluminum. A tack or nail holding an aluminum panel to
> wood will loosen the same way if the coating seal is broken and moisture -
> even humidity gets to the steel tack where it is contacting the aluminum.
>
> Unless lead is a more active metal than aluminum, a lead anode will not
> protect aluminum from corrosion. Magnesium or zinc anodes might be more
> active metals than aluminum and thus more affective at protecting aluminum
> from any contact points with steel.
>
> The TF has an aluminum water outlet elbow between the engine and the upper
> radiator hose. This elbow can become so corrosion pitted from the inside
as
> to leak. The holes in the elbow for the steel studs can become enlarged
to
> a point of weakening the seal on the gasket. This is due to the aluminum
> sacrificing itself to the studs which also seem to corrode badly.
> Electrically isolating the studs, nuts and washers from the aluminum elbow
> with dielectric plastic pieces acquired from an electrical supply house
will
> eliminate the corrosion. The gasket and the radiator hose serve to
complete
> the electrical isolation of the elbow preventing further deterioration of
> the aluminum
>
> Sacrificial magnesium anodes in both the engine block and radiator that
stay
> wet continuously from the water in antifreeze will reduce corrosion of
soft
> plugs, radiator brass etc. Anodes on the car body are in my opinion
> unlikely to protect against galvanic corrosion due to a lack of near
> continuous moisture to complete the circuit. Might work though if one
parks
> in deep puddles.
>
> Jon
>
> -----Original Message-----
> From: david.tinker [mailto:david.tinker@virgin.net]
> Sent: Monday, April 24, 2000 3:55 PM
> To: mg-t@autox.team.net
> Cc: Sleuth@usa.com
> Subject: TF Restoration.
>
>
> Hi MGT Types,
>
> You may remember the saga of my new TF body clad in aluminium alloy
rather
> that steel, and the response I had through the List on the subject of
> dis-similar metals being in close contact and the possibility of
subsequent
> corrosion .
>
> Well my friend Colin Gibson put me in touch with an Aircraft Engineer
Peter
> Tanulac, who made the following recommendations. That all mating parts
ie
> Ally/ steel) be coated with a paint called Duralac, which is used is
similar
> situations on light aircraft. Where POP rivets are used employ ally
rivets.
> He also advised the use of a Lead sacraficial annode approx 75 x 25 x
12mm )
> and attached to the bare ally body( ie metal to metal contact ) and
finished
> with a wash/ etch primer. The annode is renewed when it disappears ,
> probably in the after life!!!!!!!.
>
> My considered opinion is that if it it good enough to fly in it is good
> enough to ride in, and this is the proceedure to follow, ( unless you
know
> better ).
>
> Keep MGing
>
> David Tinker
>
>
>
>
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