Originally Posted by
DannoXYZ
Oxalic acid will eat up good metal just as quickly as rust. You want to use Naval jelly, which removes rust and stops at good metal. Safe on paint as well.
I think you would need to leave the part in the Oxalic acid for quite a while to have a loss of good metal. I and many BF members have had great results with it. Dilute solution and a few hours in the bath and then a gentle 'srcub' with a white Scott's pad and finally a quick rinse in the baking soda bucket to neutralize that acid. Dry and apply wax and or frame saver (if doing a frame) and you are complete.
I have had parts that looked like something from a scrap hauler's truck come out looking respectable to very good with it.