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

[RobT]

Hi All,
Thanks to you all for your informative responses. With Ian's caution about possible lung damage due to abrasive dust inhalation firmly in mind I intend to build a blasting box and get a compressor. Does anyone know what size of compressor (tank size and flow rate) that I would need? Money is an important consideration as is portability since I would like to use the unit around the house. Also, does anyone know what kind of attachments (like nozzles and abrasive canisters) I will need? I intend to check out the Black Beauty abrasive that Ian mentioned. Perhaps that company can provide some information also.
Ann, I very much look forward to your analysis of the differing needs for restoration and conservation. Thanks too for your compliment on my blades.
Kai, thanks for starting this ball rolling. Regarding your last post on this thread however, I must say that, unless the entire blade is uniformly black, the pits will show up loud and clear. I know this because I just spent about two years polishing the staining out of a wootz Kurdish Jambiya. (It was ok once but I'll never do it again. Life is too short.) The pitting and metal loss to this blade was severe but when the blade was polished mirror bright prior to etching, the pitting didn't look half as bad as when the blade was stained. Now that the etching is done the blade looks fairly respectable. This is why I'm so eager to pursue non-damaging methods to clean blades quickly and effectively.
Sincerely,
RobT

[kai]

Originally Posted by RobT

With Ian's caution about possible lung damage due to abrasive dust inhalation firmly in mind I intend to build a blasting box and get a compressor.

To those who are still unconvinced: Please do yourself a favor and google for silicosis! BTW, there's a host of severe health hazards associated with just about any sort of fine particles (i. e. "dust") - which also includes wood working!

[/QUOTE] unless the entire blade is uniformly black, the pits will show up loud and clear. I know this because I just spent about two years polishing the staining out of a wootz Kurdish Jambiya. ... The pitting and metal loss to this blade was severe but when the blade was polished mirror bright prior to etching, the pitting didn't look half as bad as when the blade was stained.[/QUOTE]
Yeah, pitting really is a nasty damage which tends to spoil the looks of a blade no matter what. That's why sellers usually don't touch rust encrustations - restoration tends to be a long, long uphill battle...

Rob, do you have before/after pics of that jambiya?

One possibility would be to protect the pit(tings?) with wax/etc. and only stain the smooth blade surface. That still will make the pitted areas more noticeable than in mirror polish: However, IMVHO some blades just look "wrong" if not stained properly...

Regards,
Kai