Sword Care: Oiling

Carefully maintaining your sword allows for it to not only bring you enjoyment for the years to come but even to future generations. The Japanese samurai saw themselves merely as temporary custodians of their swords, and it was important to pass on the sword in its original condition (or better), for when they die, the sword would end up in the hands of other owners who must also pass on this legacy.

The K.I.S.S. rule (Keep it Simple, Silly) is perhaps the number one rule when it comes to oiling swords. Real swords are generally made of a medium to high carbon steel and low-alloy in nature. Unlike stainless steel (which is high alloy in nature) the simpler steels are vulnerable to oxidation, and thus a thin coat of oil would prevent this.

The ancient Japanese have been using choji oil. This is made of 99% mineral oil and only 1% of clove oil for fragrance. This is incorrectly referred to as "clove oil", however, and the mistake has caused some to purchase clove oil from a pharmacy and the result is that their swords have suffered from oxidation (rusting).

Japanese choji has literally worked for centuries and is completely time-proven: just examine some Japanese swords today - swords hundreds of years old look as they did the day they were made!

An alternative to Japanese choji oil is just pure mineral oil. A common theory is that a drop of clove oil was added for fragrance because mineral oil is a laxative. Without the distinguishing smell of cloves, the Samurai's wife might have accidentally used it for cooking oil and, consequently ruined dinner for the poor Samurai!

Mineral oil can be purchased from any pharmacy quite inexpensively, again would be marked as a laxative on the bottle. Traditional Japanese choji is more expensive and is available in most Japanese woodworking stores or online stores that deal with Japanese sword supplies.

An alternative to both these two oils is gun oil. Because gun oil does not have nearly the same centuries-old track record as choji oil, it is hard to recommend it for expensive antiques. However, for inexpensive swords or replica swords in general, any gun oil without corrosive agents may be used, but consult with the manufacturer. In my own personal experience, Remmington Oil works well (i.e. RemOil) but I find that Break Free CLP (as opposed to just "Break Free" - a different product, same brand) coats a bit better.

Be careful not to get oil under any cracks or openings at the hilt where it can potentially trap moisture. With Japanese swords, it is advisable to remove the blade from the hilt, to clean and remove all the old oil before applying the new. With European swords, sometimes it is not possible to disassemble the sword without unpeening the tang, so proceed with caution.

A few drops will do, and spread it with a lint free clean towel. All you need is an extremely thin layer of oil that serves as a micro-thin protective layer between the steel and the elements.

Avoid vegetable oils, as they can go rancid and attract dust. Some use olive oil, but I discourage that because it can "gunk up" when the sword is within its scabbard. Again, stick with what is time-proven. In this case, pure mineral oil or Japanese choji oil is good and will work for Japanese and non-Japanese swords.

Also avoid WD-40 as a protector. It's primary usage is cleaning; however, its distillates will evaporate and leave the blade unprotected. Also when using it, be sparse; excess amounts can run into cracks or openings at the hilt.

For Japanese swords, antiques, etc. it is advisable to avoid Tuff Cloth, waxes, silicone-based gel, vaseline, petrolium gelly, Cosmoline, etc. Some of these contain chemicals that attack blade steel. If not, avoid them for the reason that they are more work to remove and can trap moisture. Once you coat up a blade with the aforementioned and sheath the sword, the scabbard interior will be very hard to clean.

Again the golden rule: keep it simple. Very simple. The simpler the solution the better the protection.

And if it does so well with historic Japanese swords, it would do just as well with antique swords of other cultures - or modern custom swords made from simple low-alloy carbon steels to pattern welded "damascus" steels.

Summary

• Time proven oils: pure mineral oil, Japanese choji oil (99% mineral oil, 1% clove oil for fragrance)
• Acceptable oils: RemOil, Break Free CLP
• Avoid things that will "gunk up" inside the scabbard, substances containing corrosive chemicals, etc. The simpler the solution the better the protection.
• Just a few drops will do, and spread it thin with a lint free kitchen towel.