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an example of galvanic corrosion - a dead pinto alternator
FuryRebuild - 21/6/13 at 08:35 PM

So, I am about to try and sell my full fury pinto outfit again, and have unboxed the alternator from where I stored it over winter.

By storing it, I mean putting it in a plastic sealable box, with some other stuff. one of the things in the set of 'other stuff' was a steel door hinge. They were touching. Here is the result, for your amusement:

don't do this at home
don't do this at home

It's so mullered the pulley won't even turn.

snapper - 21/6/13 at 09:38 PM

Ohh that'll clean up ok

blakep82 - 21/6/13 at 09:53 PM

Thought steel rusts to save aluminium?
Wasnt that the problem with old landys? The aluminium body always looked good, but the chassis rusts and protects it?

mcerd1 - 21/6/13 at 10:10 PM

quote:
Originally posted by blakep82
Thought steel rusts to save aluminium?
Wasnt that the problem with old landys? The aluminium body always looked good, but the chassis rusts and protects it?

other way round - the more reactive metal protects the less reactive one

on its own aluminium is protected by a thing layer of its own oxide (anodising makes this layer thicker) but it can't save it from galvanic corrosion when its in contact with steel


the landrovers have big problems with the alloy panels corroding where they are in contact with steel (the doors are an alloy skin over a steel frame, its always the alloy that goes first)
mind you the steel chassis rust just like normal too as they don't actually have that much contact with the alloy....

Bare - 22/6/13 at 01:33 AM

A Pinto in my part of the world is regarded about equal to a fresh pile of Dog Poo.
Move on.. a Pinto in it's entirety, is simply scrap metal, by any descriptor.

Mr Whippy - 22/6/13 at 06:17 AM

quote:
Originally posted by blakep82
Thought steel rusts to save aluminium?
Wasnt that the problem with old landys? The aluminium body always looked good, but the chassis rusts and protects it?


Na it's actually the other way round, the steel rots the aluminium body very badly often cutting holes right through in the shape of the steel bracket and the aluminium turning to white powder, why when they knew of this they didn't simply put a gasket between the to?

sjmatthews - 22/6/13 at 06:51 AM

quote:
Originally posted by Bare
A Pinto in my part of the world is regarded about equal to a fresh pile of Dog Poo.
Move on.. a Pinto in it's entirety, is simply scrap metal, by any descriptor.


Be careful not to offend a large number of forum users that continue to use these old engines. The Pinto may not be the ideal engine of choice nowadays, but they're not a bad engine and cheaply provide bucket's full of fun in locost kit cars

FuryRebuild - 22/6/13 at 07:40 AM

quote:
Originally posted by Mr Whippy
quote:
Originally posted by blakep82
Thought steel rusts to save aluminium?
Wasnt that the problem with old landys? The aluminium body always looked good, but the chassis rusts and protects it?


Na it's actually the other way round, the steel rots the aluminium body very badly often cutting holes right through in the shape of the steel bracket and the aluminium turning to white powder, why when they knew of this they didn't simply put a gasket between the to?


Bit out of order there. There are plenty of people running on Pintos, and some series where the engine is mandated. It may be heavier than more modern ones, but it's bomb-proof. If you'd taken the time to read anything about my other posts rather than jump right in, you'd know why it was up for sale.

One of the really nice places about this forum is that it's very much like a friendly chat down the pub, and is remarkably light on armchair-engineers.

myke pocock - 22/6/13 at 07:55 AM

Oh well Mr Bare. Its a pretty rapid pile of dog poo then!!!! What you using, a Trabant engine maybe?

owelly - 22/6/13 at 09:21 AM

Worry not. I'm sure most folks on here can take Bares contributions and opinions for what they are.

MikeRJ - 22/6/13 at 02:27 PM

I'm not convinced the steel door hinge was entirely to blame considering the alternator is bolted to a steel bracket!

You don't get bi-metalic corrosion without introducing some moisture though.

omega0684 - 22/6/13 at 03:33 PM

quote:
Originally posted by Bare
A Pinto in my part of the world is regarded about equal to a fresh pile of Dog Poo.
Move on.. a Pinto in it's entirety, is simply scrap metal, by any descriptor.


You clearly haven't been in a 200+bhp pinto'd kit car if you're making comments like that!

[Edited on 22/6/13 by omega0684]