By the way, there is another EDR method rarely mentioned on this NG, not
mentioned in any of the normal derusting papers. Orrin, this one may
interest you. The method is passive rather than active -- in other words,
you don't have to add energy in the form of electricity. No more wires.
Simple. Make up some strong hot lye, dissolve in a chunk of zinc, and
drop in the rusty part. The zinc reduces the oxidized iron.

There are Web pages about this -- google on lye and zinc and you'll see 'em.

If you don't think you have any zinc, you're likely wrong. Many inexpensive
cast metal items are made mostly of zinc. Car door handles, mirror bases,
lamp bases, stuff like that. Try a coarse file on it, if it peels away like
butter that's the stuff. It's been posted on this NG that lye will bubble on
zinc (pot metal) but not on aluminum.

Grant