Rust or paranoia?

[Listeryoyo]

I have a late nanbokucho period kizori school blade. It is in longer term storage in the shirasya. I carefully remove the old oil using clean microfiber cloth and denatured alcohol about every 4-5 months, and reapply a thin layer of zoom clear oil. I really never use uchinko. I store it flat, in the Shirisaya in a seldom used closet. Soon after some home remodeling it will be on a rack displayed prominently.

 

Each time I examine it it seems like I notice a few more rust blemishes. After looking through a magnifying glass they are tiny pin like dark spots. It looks like tiny old spots that , maybe, I hadn't noticed before.but perhaps had been there before. It kind of drives me nuts that I'm doing something wrong and I could be the moron ruining a 650 year old hozon blade.

 

Any feedback ? Does anyone ever convince themselves they're creating a problem when there isn't one?

 

Thanks,

 

Big Dave Liss

[ChrisW]

Perhaps some Choji oil would be best? Surely the ways that have been done for hundreds of years are valid if we have blades that have survived using those ways.

[Ken-Hawaii]

Doesn't sound like you're doing anything wrong, although I've never heard of zoom oil. Could that oil be contaminated with water? But, what concerns me is the alcohol you're using. Although it's denatured, alcohol is naturally hygroscopic, & unless you can dry it 100%, I'm betting that there's enough H₂O to eventually cause those rust spots. There's no real need to use alcohol, at all - just wipe off the old oil, & add a new film. Good luck.

[Michaelr]

Are the spots only on one side? The reason that I ask is that I have never heard of sword in Shirasaya being stored flat. I was always told to store my blades on their back. Just wondering if the spots have something to do with the side of the blade that is on the bottom being in constant contact with the side of the Shirasaya? I have heard stories of blades rusting in their Shirasaya after long term storage. Just a thought.

MikeR

[Stephen]

i never use alcohol unless its a new blade that needs obvious cleaning of  old oil that's changed color.

 

 you can over care, like Ken i just wipe off old oil and very light coat new. if you see beads your using to much oil.

 

Michael brings up a good point. design of saya or shirasaya is for it to rest on mune. often stored war relics standing in corner of closet has rust on its tip. Gravity rules all im 2" shorter than my 6'3" youth, it also pulls moisture to its lowest level. 

[tbonesullivan]

I would generally avoid using any type of solvent like alcohol that can absorb water, for reasons stated previously. Old swords with grain and small kizu can possibly absorb it, which draws in water, even after oiling.

 

If it's already been cleaned and oiled, I would think a simple wipe down with the micro fiber cloth, and then re-oiling would be sufficient.

 

Now, one thing I am always kinda iffy on is how much oil to leave on the blade, and what to use to apply it to the blade.

[Stephen]

David just a light film.

Old t-shirt cut into 2" square kept in baggie or plastic box.

[IJASWORDS]

Denatured alcohol DOES contain water. Never use it . Isopropyl alcohol 100%,  is good . 

[Vermithrax16]

Denatured alcohol is just ethanol that has methanol added to it, to make is poisonous and discourage the drinking of it. Any alcohol that is not anhydrous has some water content. 

[SAS]

Alcohol is hygroscopic, meaning it absorbs water readily. Water can be removed from alcohol by freezing, as the water freezes and the alcohol remains. Short of a full polish, using uchiko and oil may reduce rust spots. Excess oil in humid areas will actually promote rusting, in my experience.

[Listeryoyo]

Thank you all. I do store it on its back, not to one side . I will use 100 % isopropyl , but only a time or two per year and reapply a thin coat. Other times is usually only wipe and re-apply. I use Ren-wax on some antique guns. Has anyone ever used on a nihonto for long term storage?

[Listeryoyo]

Btw... I was told by Tsaruta, the main guy at Aoi art in Japan , that he preferred a thin layer of light sewing machine or gun oil over choji oil for preservation. I asked him about history , etc, and he replied that some more modern inventions were better. He said to make sure it was clear, not a dark hue as it could shade the steel over time. He suggested choji contained "organic" content that dried faster and can gum up over time. That's what I gathered from his limited English response.

[tbonesullivan]

As far as I know, Choji oil is just light mineral oil with clove oil mixed in. Hopefully someone will correct me if I'm wrong. Maybe the clove oil has some water absorbing properties?

 

Either way, there's a TON of different types of light oil out there. In general you'd want something that is entirely hydrocarbon, with no ability to absorb water at all.  It also can't be something that evaporates or has any type of pigment to it.

 

Zoom oil actually looks pretty good. It's listed as a "lily white lubricant / stainless / highest quality water white sewing machine oil"