Solarbird 
hey, there’s a bike chain under all that rust!
(continued from: https://mastodon.murkworks.net/@moira/115069944638186131 )
i’ve put it in denatured alcohol for degreasing and actual cleaning. not sure how long tho’? it’s a lot cleaner already, rust aside.
WHAT’VE WE LEARNED TODAY SOLARBIRD?
don’t put your glass full of evaporust and metal into the ultrasonic
technically learned this yesterday BUT it’s important
Paul Southworth@moira The chainring is not riveted to the crank arm. What you are seeing is a pin on the crank arm that prevents the chainring from rotating independently from the crank arm. The chainring can be replaced but unless it's unusable I would just ride it.
@pws i don't want to replace it it's just way easier to derust it if it's not on the bike
and riveted or not this makes it look harder to remove
@moira The pin won't slow you down at all. It will slide right off that once you remove the crank and the lockring holding the chainring on.
If you have access to Simichrome polish that will take the rust right off. It's not available everywhere due to nasty chemicals, but it does work very well.