removal of cosmoline from Japanese sword blade

[Kenneth Whitcomb]

Hi, I have obtained two Japanese NCO swords (matching numbers, beautiful blades) and both blades are coated with cosmoline that has been present since 1945. I want to remove the cosmoline. Is it safe to use WD-40? The cosmoline does not appear to be gummy. Thank you for any suggestions you can offer. Ken

[Brian Wolfe]

Hello Kenneth,

Ah the smell of cosmoline, we used to refer to it as axel grease and military rifles used to come "packed" in this stuff.

The NCO sword is not hand made but rather mass produced. One would have to worry more about the hand-made blades as there is a chance that anything you use could penetrate between the folded layers of the steel. In the case of the NCO this is not an issue.

Use mineral spirits to clean off the cosmoline. Actually I have used lacquer thinner and that works very well but is not very nice to work with, and quite flammable. If you can disassemble the sword before you start that is best as then the mineral spirits will not run into the handle assembly. To protect the blade afterwards use a good paste wax. This is NOT advisable on a hand-made blade but on the NCO sword it will work just fine.

One last thing, tell anyone who wants to "look" at the blade NOT to touch it. They will anyway but you have my permission to remove the offending hand with the second sword. Only kidding of course, you don't need my permission, it's a given.

Please post photos of the swords when you can as I am sure many members (including myself) would like to see them.

Regards

Brian

[Kenneth Whitcomb]

Thank you for the information Brian. Mineral spirits seem safe. It was also suggested that I heat the blades with a hair dryer and just wipe the cosmoline away. Would there be enough heat generated to discolor the blades? I notice that the handles are held with a screw so if I can remove the screw without scratch marks I will do so. I will have to do some homework to figure out how to post a photo. I would like to show the blades before and after. I am going to sell one of the swords and keep the other. It has been an education for me to look up the various armory marks and inspection marks present. Setting a price is always a hassle for me. Using ebay is useless because of the junk being offered. Thank you again for your time and knowledge.

[Dieter3]

+1 on the mineral spirits! Have done my share of cosmo-queen SKS rifles, and works nicely for metals. If you've got yourself handy a 5-gallon or so plastic bucket and a can of mineral spirits, you're all set! A bucket with a screw top lid all the better, though maybe harder to find, you can keep the used spirits around and reuse quite a bit before you need to filter or dispose. I would not even bother with heat. Just get a good, nylon brush like a kitchen scrubber, or even a toothbrush and you'll make adequate work of that goop!

[Kenneth Whitcomb]

OK, mineral spirits it is. My quest is to find a long open top plastic type of container such as might be used by dry wall installers. It must be long enough so that I can lay the blade inside for a good soak. I can use this tray for other metal parts as well. Thanks for all the tips.

[Dieter3]

That'll work! Something like that though, you won't even need to soak it. The spirits will work it away quick with any brushing force, even older, crustier stuff. Post some pics when you can!

[Brian Wolfe]

For a good tooth brush for cleaning almost anything I suggest that you go to the pharmacy or chemist or drug store (whatever you call it in your area of the world) and purchase a tooth brush used for cleaning dentures (false teeth)these are too hard for your own teeth but ideal for dentures (or so I am told). I found out about them when I collected fossils. The more they wear down the "stiffer" the bristles become and the better they work.

Here's a photo of the one I use as you can see 40 years of cleaning fossils, minerals and military items has taken its tole.

Regards

Brian

[Kenneth Whitcomb]

For a good tooth brush for cleaning almost anything I suggest that you go to the pharmacy or chemist or drug store (whatever you call it in your area of the world) and purchase a tooth brush used for cleaning dentures (false teeth)these are too hard for your own teeth but ideal for dentures (or so I am told). I found out about them when I collected fossils. The more they wear down the "stiffer" the bristles become and the better they work.

Here's a photo of the one I use as you can see 40 years of cleaning fossils, minerals and military items has taken its tole.

Regards

Brian

[Kenneth Whitcomb]

UPDATE: As suggested I used mineral spirits to remove the cosmoline. Surprisingly I only had to place the spirits on a rag and wipe off the cosmoline. Super easy! So, next question: what do you suggest I use to remove the smell of the spirits from the blades? Once again, these are machine made blades. Thanks for your suggestions. Ken

[Dieter3]

UPDATE: As suggested I used mineral spirits to remove the cosmoline. Surprisingly I only had to place the spirits on a rag and wipe off the cosmoline. Super easy! So, next question: what do you suggest I use to remove the smell of the spirits from the blades? Once again, these are machine made blades. Thanks for your suggestions. Ken

I would try an alcohol like ethanol. Propanol would probably work too. Then I'd grease or oil that thing right after.

[Kenneth Whitcomb]

Just got back from a short trip. I will follow your suggestion about ethanol, etc. Thanks once again. Ken

[Harvey]

I see that it's been over a year since the last post - any pics of the swords to post Ken?

[Les]

I would try an alcohol like ethanol. Propanol would probably work too. Then I'd grease or oil that thing right after.

Those would remove the cosmoline, however, putting anything on the blade afterward is something to consider before doing it, and then putting oily or greased blades back into the scabbard or saya. If the blade is a traditional hand made one pre-dating the modern era, decide if the condition and value of the sword could be affected by what you do. If the blade is a mass-manufactured machined piece of steel made between circa 1920-1945, how the cosmoline is removed and what you do in the process and afterward may not be all that important.

The best surface protection for Japanese blades with a high polish, is to keep the blade as dry as possible, and wiping it down every few days or so, to keep moisture and rust from starting on the surface. If possible, keeping the blade in a dust free, temperature and humidity controlled environment will go a long way to keeping moisture down and away from the surface.

A grease or oil "wets" dust and other particles, which helps the dust (whatever) to stick to the surface. When the blade is put back into the "saya" the gritty surface can rub against the polished surface and in time can leave rub marks. Oils or grease on the surface of a blade can be transferred to the inside of the saya, and once that happens, the oil or greasy spot will start picking up stuff that can and will rub on metal, and vice versa.

The Japanese used clove oil to clean a surface and/or displace water or moisture from the surface of the metal. The heavier oil would display the moisture to the surface of the oil. The surface is then lightly wiped with a special absorbent rice paper to remove the surface moisture, then the oil, and finally to leave a bare metal surface. Then, the next traditional step is/was to tap a cloth ball on a stick, filled with a powder or pomice and spread along the blade, that was used to absorb any moisture that might come in contact with the blade inside the saya.

Japanese blades were usually kept as dry as possible, and any dust or grit adhering to the powdered surface would be wiped off during the many inspections of the blade. The Japanese guy who carried the blade daily and felt his life depended on the condition of the sword, may have cleaned and wiped his blade daily, a practice not so different from the more modern soldier who is taught and told to clean his weapon daily.

[Kenneth Whitcomb]

Sorry to say that I still do not know how to post photos. i can adjust the size, etc but when i try to post all I get is a photo number but no photo. This is maddening. I'll stop pouting and try again. Thanks, Ken

[PKeating]

Old post I know but for the record: I used to use a space heater/paint dryer to remove solidified Cosmoline from various items, including ex-WD BSA and Norton motorcycle parts. Just set the item about two metres from the heater on medium to hot and wait. The goo will warm up slowly, liquify and run off. With items like swords or firearms with wooden furniture, obviously the non-metallic parts should be protected from direct heat, even hot air.

PK