[Leica] Mag wheels - way,way OT

[corkflor at iol.ie (Alex Hurst)]

Frank Dernie writ in part:

>Hi Douglas,
>It is true that very few metals are the used as the pure element, 
>AFAIK, and certainly the metals I use, are all alloys. Ally wheels 
>for cars are mainly aluminium, though there is a small percentage of 
>magnesium and other alloying elements. Ferrari use magnesium wheels 
>on their road cars but they have to be immediately surface treated 
>and repainted to avoid corrosion if scratched.  "Ally" wheels 
>corrode readily if used on salt de-iced roads, unless painted, but 
>not as fast or badly as magnesium.

>Aluminium alloys are significantly stronger than magnesium alloys 
>but the low density of the latter affords higher specific strength 
>and stiffness. Magnesium alloys also possess good machinability and 
>can be readily welded using TIG. Having said that they are extremely 
>soft and a "bulk" penalty must be paid as a large volume of material 
>is required to achieve equivalent properties to other structural 
>metals. Furthermore they are expensive and their resistance to 
>corrosion is not as good as that of aluminium alloys.
>ed in sheet fabrication processes.


For both personal, and economically practical reasons, I am loath to 
part company with my immaculate '89 BMW 530i SE (157,00 miles +). It 
has mag/alloy wheels, which have never caused a moment's corrosion 
problem. Somehow I don't think BMW would have ever marketed the car 
if it were subsequently going to melt down on its tyres.

Funnily enough. all my Leicas,  M2 to M6, don't have any problems 
either. But then they haven't been left out in Irish rain for 16 + 
years.

Seems to me that good car manufacturers expect a lot of rain on their 
products, but good camera manufacturers don't.

The only camera (which I have) which would probably survive this test 
is the Nikonos.

What it all boils down to is that there are horses for courses. The 
problem with metallurgical arguments is 'what do you do with 
plastic?'  :-)

In other words, the whole thread is not exactly relevant (IMHO).

Best

Alex






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