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Can metal chassis become defective? I

I have learned from a top repair technician with 45 years experiance that all internal electronic components can go bad after enough time (resister, caps,tubes) INCLUDING the actual metal chassis. He claimed that if an old unit is not working that you could replace ALL the electronic components and it still may never work because the metal chassis is WORN OUT. His theory is that the electrons that go into the chassis ground have (over the years) filled up the outer atomic orbitals and interatomic space with too many (used) electrons forced into the metal (aluminum for example) and that the metal is now defective for a ground chassis SINCE THERE IS NO SPACE LEFT FOR THE ELECTRONS. The metal is WORN OUT. It becomes a radioactive isotope of aluminum since there are excessive electrons in the outer orbitals, and unusable as an electronic chassis. If this is not the case then where do the electrons go if the chassis is not grounded to true earth ground (cold water pipe only)or through a proper three prong plug?
mint604
rcprince
2,830 posts
 
Joe, thanks for the kind thoughts. I wanted very nuch to go and meet some of the Philadelphia members; we'll probably have one early next year at Community Audio, maybe we can work another joint meeting then. Hope to see you at least at the holiday party, already picked up some nice door prizes!
mint604 OP
59 posts
 
Standed wire wears out sooner than solid wire. Thin chassis wear out sooner than thicker(gauge) metal. Aluminum wears out sooner than cooper, brass or stainles steel. Therefore inorder to restore an older tube amplifier,you will need in addition to all new caps and resistors ; all new solid wire and thicker gauge stainless steel chassis. Only transformers improve with age. Have you ever noticed on very old tube equipment that the old aluminum chassis appears to have a whitish "patina"? This is PROOF that the chassis is defective for use as a conductive ground, this is not rust or oxidation since aluminum cannot rust. These chassis are toxic and have transmuted into a radioactive isotope of aluminum and can cause anemia and bone cancer.
inpepinnovations1e75
395 posts
 
Mint604, actually aluminum does corrode at the surface, but contrary to iron, the corroded surface (the patina, as you put it) protects the rest of the aluminum from further corrosion. It is true that aluminum oxide doesn't conduct electricity, however. I am not sure about the isotopes, though!
Bob P.
jdcrox
119 posts
 
And aluminum alloys corrode at a considerable rate. And since pure aluminum is so soft, it is rarely used for anything structural. I cant imagine a chassis being made from pure aluminum.
Much of the aluminum used in aircraft construction has a thin layer of pure aluminum over the aluminum alloy to prevent surface corrosion. Known as "alclad".
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