Larry,
Pot metal
is an alloy of light metals such as zinc, tin, lead, aluminum. By alloying
these together, the melting point is lowered, making it easier to work with.
The molds are steel, not clay or sand casts. This allows fast production with
very high definition and intricate shapes. Just inject in molten metal and
eject a part, over and over. The reasons for using pot metal are its low
melting point, fast production, cheap material costs, light weight, and high
definition. Unfortunately, these cheap metals are prone to corrosion and
brittle, so they have to be protected by plating.
From the
viewpoint of an automobile manufacturer, pot metal is plenty good. Cars were
never intended to have a life expectancy much beyond 10 years. And the owner of
a worn out 10 year old rusty beater wouldn’t care much about the pot metal. OEM
pot metal on our cars is now 50 years old, much beyond what was expected of it.
Be thankful that Mopar pot metal was MUCH better than GM’s.
Dave
Homstad
56 Dodge
D500
-----Original
Message-----
From: ALIENVOICE@xxxxxxx
[mailto:ALIENVOICE@xxxxxxx]
Sent: Tuesday, August 22, 2006
9:33 PM
To: dhomstad@xxxxxxxxxxx;
L-FORWARDLOOK@xxxxxxxxxxxxx
Subject: Re: [FWDLK] Pitted
Pot-Metal
What is pot-metal made of? What about this metal makes
it so prone to pitting? When was pot-metal developed and adopted for
cars, and how is pot-metal formed into the myriad shapes that was made for our
(and other) cars of the ForwardLook era? Is it molded from clay or steel
molds?
Sorry for all the questions, but I have never understood why pot-metal was
adopted (cost?) and used when it is so brittle and pits so readily. I am
sure one of the historians or metallurgists on this list may be able to
enlighten us. Thanks.
Larry (Akron)