Electrolytic rust removal - please add your experiences!

[kai]

Originally Posted by RobT

Although there are patches of bare grey steel, most of the blade is covered with black oxide (magnetite Fe3 O4 ?). This is proving very difficult to remove, especially since the blade is severely pitted.

Thanks for your updates, Rob!

I'm not sure I'd want to remove all of this patina.

If you're desperate enough, you could try etching with fruit acids (e. g. lemon juice) which tends to remove magnetite also (but will also etch the blade, i. e. make it rougher. It also works in pitted areas but don't expect wonders - keep brushing the blade from time to time to remove losened sludge. Fruit acids will also darken the blade and, thus, may make pitted areas less noticeable.

Regards,
Kai