My grandfather gave these to me, oh.... 25-30 years ago? This is pretty much the way that they have always looked and I hadn't really given it much thought. Then, the other day while obsessively polishing some new-to-me tool, I suffered a moment of all too rare insight. Some of the tools that I already have are pretty cool! Seeing something every day, well, you tend to not see it anymore.
And I do use these nearly every day. My hands know them and the sharp edges have been rounded down from decades and generations. New tools are harsh and bright and the steel feels funny. Brittle, rather than strong and resilient. These are old, but are beginning to lose the battle against dissolution. Ah, time (and spit!), the universal solvent....
Electrolysis bucket. Rebar distributed around the perimeter acts as the anode and connects to the positive lead on the battery charger. Wow! Ugly bucket AND charger, haha! New chargers have protective blocking diodes and stuff, so they might not work. Not an issue here, obviously. Hey Dad, if you were wondering where your old battery charger went, here it is...
Baking soda, a few tablespoons worth, improves the conductivity of the water that will fill the bucket. You can use more powerful chemicals, but cheap and safe baking soda works fine. These tools weren't too rusty, so I left them in the bucket overnight @2 amps, then scrubbed with a synthetic pad.
IMPORTANT! Dry and oil the newly clean stuff IMMEDIATELY, or it will instantly rust! Electrolysis, acid washing, de-greasing..... all of these processes leave the surface of the metal unprotected. You need to oil or paint right away. Today, not tomorrow!
See the nice, burnished Gray finish? Electrolysis doesn't harm well-adhered paint or bluing, but will oxidize bare steel to a nice dark gray. Fine by me. Check the progress periodically, but don't worry. The tools won't dissolve and you won't get shocked. You can put your hand right in the water and, provided that your charger works properly, you won't feel a thing. Not even a tingle. At these low (sub-6 amp) power settings, you don't harm the tools any and it will make the rust disappear. This is the safest way to remove rust, bar none. Rust removal for lazy people.
**Caution!** The electrolysis process removes rust and...... sometimes the black finish on Japanese tools is a RUST finish! You can put a thick rust oxide finish on steel by allowing/forcing the metal to rust, then submerging the rusted metal in boiling water. The red iron oxide turns into black magnetite..... rust blackening. THIS MAY OR MAY NOT BE REMOVED BY ELECTROLYSIS! I have used electrolysis on some blades.... fine. Other blades... finish was removed. Go figure...... I'll let you know when I learn more.