[A. G. Maisey]

Yes, that was what I had in mind when I wrote:-

"--- I do not know what the "best" method is to derust ferric material ---"

that electrolytic method, but I could not recall what it was called.

I've just AI'd it, & it does seem to be pretty effective, however, boring down into the details, it does seem to have some limitations.

It is something that I would never use, simply because of the playing around that needs to be done, the power source & etc & etc. What I do with vinegar is safe, effective, & no problem, the vinegar definitely does not cause any deterioration of the unrusted material.

However, for somebody with lots of time who enjoys playing with these sort of things, I think it could be quite an interesting method to use, & it does seem to be quite effective.

HARD RUST

the hard rust that we often encounter on an old blade is picked off with a sharp tool, see Post #17. This does not damage the blade surface in any way, the rust is simply gently removed & the blade goes back into the vinegar to clean up the residue.

I once spent about 12 months cleaning a Balinese blade that had very beautiful, original warangan, but was peppered with tiny pinholes all of which had rust in them. I worked an hour or so at a time, most nights, using magnification, strong light & various needles, I picked all the rust out of every hole. I still have that blade, still with its original warangan.