Join Date: Nov 2009
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is the polishing just for aesthetics ?
No, it's to achieve a totally smooth surface with no microscopic crevices that will allow crevice corrosion to take hold.
Stainless steel does not rust on the surfaces exposed to oxygen, but they do corrode and fail in an anaerobic environment, which is usually the part of the chainplate that is encased in the deck.
Alacrity, 1981 Tartan 33 #168