Diecast Model A deterioration

There are two Saturns in the parking lot where I work and I see nothing fragile? In fact, all of the plastic panels look like brand new while the hood and roof is faded bad from the sun. One is an early 90s and the other a 1997. The 97 was hit by a plow last winter and the panel held up fine.

To be honest, I've never seen Saturn panels show any signs of being fragile.

:rolleyes:

This reminds me of what plumbers must have said about PVC drain pipe when it first came out. "Cast iron and poured lead is the only way!". Now everyone wants it gone............

Yep they are tough and can hold up to some punishment
 
Tiny's son needed the roadster to make a hi-boy so I mailed it off today.
A good father/son project. Have fun. Thanks for all of the replies, even the off track ones. :rolleyes:
 
Tiny's son needed the roadster to make a hi-boy so I mailed it off today.
A good father/son project. Have fun. Thanks for all of the replies, even the off track ones. :rolleyes:


This is why this forum needs a "like" button.
Or, an "awesome" button.
 
Thanks again Vern. I haven't told him that this is on the way. I'm letting it be a surprise. Kids love getting mail!!!
 
Looks like bad pours. Like incomplete pouring of the pot metal in the mold and then more metal was poured in. I used to make sinkers for fishing and this happened some times.JMHO
 
Thanks again Vern. Jack really likes the "hotrod" look of the lack of fenders. He already asked if we could pull the bumpers too! This one appears to be perfect hotrod material too. It has a 32 shell and a V-8 but still retains the 31 gas tank. Our stocker has the 4 cylinder and A shell still.
 
Cool job with the model cars! In engineering schools they run you through a materials properties class and the prof told us this story:

Pot metal, Zamac, and other die casting alloys are often an alloy of tin, lead and zinc. The tin part has two different phases, or conditions of the metal. One phase is metallic and the other phase is a ceramic-like phase. The ceramic phase is brittle and crumbly.

As the story goes, during the invasion of Russia by Napoleon's army, they got caught in the Russian winter. The French uniforms were held together by tin buttons. In the cold, the tin changed phase, the buttons fell apart and the Frenchmen couldn't keep their clothes on.

A lot of the cast pot metal hood ornaments and such suffer from this disease, and that may be what got your model cars.

John
 
I collect diecast toys (Dinky Toys), also made from the Zamac alloy, and a common malady many years ago was what was called "metal fatigue". This was not caused by temperature or humidity as much as impurities in the alloy used. Lead, even in tiny amounts, would result in unstable metal, that would crumble over time. Models that did not crumble and fall apart would grow in dimensions to a visibly larger size. After this was found out, manufacturers were much more careful about the purity of the casting material.
Terry
 
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