Originally Posted by
unworthy1
good luck! that's a nice looking stem, too, what brand izzit (if you know)?
My guess based on less-carefully measured acid baths is the rust will come off (but after you also wipe the parts off with a rough cloth) but usually paint stays put (even crap quality paint) UNless the paint was on top of rust, in which case it ALL will be removed (as will chrome) with that rust.
YMMV
Oh and since that stem has a brazed seam, maybe try to minimize time that it steeps in the acid, just in case this Sulphamic stuff attacks the bronze
Not sure of the stem make yet. Will pop a photo on, if you have ideas let me know. I have a feeling the acid will not do too much, but who knows! Lunch tomorrow is 24hrs of a soak, if nothing, then in goes a another cup!
It s a very valid point re the braze but if it attacks the braze then let it be so on the stem rather than the lugs, at least we will know!
Photo of the rusty stem