top tube rusting around a cable boss.

[Dr Luxurious]

20 years of dripping sweat has finally worked down to the 853.
Suggestions on how to stop it?

I do NOT want to media blast it and repaint the whole thing. I need to keep it as originale' as possible.

I'm guessing there's no magic bullet; I'll have to sand off the rust and seal it w/ some kind of top coat, right?

[AngryScientist]

20 years of dripping sweat has finally worked down to the 853.
Suggestions on how to stop it?

I do NOT want to media blast it and repaint the whole thing. I need to keep it as originale' as possible.

I'm guessing there's no magic bullet; I'll have to sand off the rust and seal it w/ some kind of top coat, right?

right.

get a wirewheel attachment for a dremel and get all of the rust off, get to bare metal. prime, paint. use automotive touch up primer and paint, available at any auto parts store.

https://www.fdgate.com/photo-4/30pc-steel-wire-wheel-wire-brush-polishing-disc-abrasive-buffing-grinding-head-set-deburring-mini-drill-dremel-tools-accessories.jpg

http://i.ebayimg.com/images/g/Zg4AAOxycD9TW4Tr/s-l300.jpg

[Ralph]

I would also use a acid wash on spot after the rust removal to kill whatever rust you didn't know you left behind. The drill brushes will leave some residue behind. (I used to do some hi end automotive restoration....and after hours of using a handing sander, would then wash a fender down with an acid wash before primer....that killed any rust remaining)