Originally Posted by
Mike Mills
I was not clear about pinholes. There were probably pinholes or small chips in the paint (not in the steel tubes) which allowed moisture to corrode under the paint (filiform corrosion).
If I understand you correctly, I should remove the paint, clean the rust off using oxalic acid (Naval Jelly) and then touch up the paint job. Is that correct?
Naval Jelly ≠ Oxalic Acid
Naval Jelly is phosphoric acid, which is more acidic than oxalic acid. You'll probably be fine using it but it may be a little harsher on paint and chrome than OA. If there is filiform corrosion under the paint then yes, you understood me correctly. First remove the paint and rust --Either scrape the paint off and use the rust removing acid of your choice or simply sand both the paint and the rust away-- taking care to get
all of the rust and then apply something to protect the surface, such as paint. A search of Oxalic acid or rust removal will turn up a number of exhaustive threads on the subject. Good luck!