All good suggestions below, however, another possible route...shallow cake pan (thrift store teflon onesw are the best) with evaporust for 24 hours. rinse in hot water while using a 3M pad. Then bar keeps friend with a toothbrush and a 3m pad again. Sometimes I have resorted to the foil and BKF as well.
And then I buy a new part...I kid I kid...sort of.
Originally Posted by
merziac
Turtle wax rust remover and chrome cleaner will get at least half of that off, green plastic bottle, chain auto parts store, Auto zone, Pep boys, etc.
Slather, sit, scrub and repeat, small stainless and or brass bristle brush.
These will clean up well and yep, likely no chainring swapping on these, there are probably some floating around but most will be the same as you have or only a tooth or two different.
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