Sword Polishing

Gyakuto

Senior Master
Supporting Member
Joined
Nov 21, 2020
Messages
3,774
Reaction score
3,090
Location
UK
I’ve been running a little (unscientific) experiment to see if modern methods of protecting steel from corrosion are more effective than traditional ways.

I wanted to compare ‘Break Free CO Collector‘ anti-corrosive properties with traditional sword (choji) oil.
7BC77E76-F29A-4EB0-9BC9-93679E9F118B.jpeg
B4507D6B-C7DD-4386-A0EA-3E2CAF9B9B1F.jpeg

Two shinken were cleaned using the traditional method every 2-3 months. One was oiled with choji oil (see above) and the other with ‘Break Free CO Collector’. Both were stored in the same gun case with silica gel desiccant packets.

I noted, when applying the two different oils, that the Break Free CO Collector tended to ‘bead’ on the blade surface. It was assumed that capillary action would distribute the oil over the blade surface in time, but this proved not to be the case. The choji oil, on the other hand, formed an even layer over the entire surface of the sword‘s blade.

After a year, the shinken oiled with Break Free CO Collector had tiny spots on the ura side of the monouchi. They felt rough to the touch and on inspecting with a jeweller’s loop, were identified as spots of rust. The choji oiled sword was free of any corrosion.

I can only conclude that the beading property of Break Free CO Collector left areas of steel unprotected and exposed to ambient oxygen and moisture, leading to corrosion.

In conclusion, I would recommend using traditional choji oil to protect shinken from corrosion.
 
I subsequently decided to attempt to restored my corroded shinken to it’s former glory.

I applied Jenolite rust remover to a small patch of steel where corrosion was present. I followed the instructions carefully. On wiping the Jenolite away, the rust spots had completely disappear but an ugly grey patch was visible where the Jenolite had been applied.

I then used 0000 grade wire wool to smooth the slightly roughened patch but, unfortunately the discolouration remained.

I then took a tube of Autosol Metal polish and applied a little to the grey patch and used the 0000 grade wire wool to polish the area. After several minutes I used a lint-free cloth to remove the residual polishing paste to reveal a beautiful, mirror-like shiny steel area, matching the corrosion free areas of the blade!

After a few minutes of joyous dancing, I repeated the process on the other corroded areas of the blade to be left with a beautiful shinken!
 
I don't know what chemicals are involved in the traditional cleaning, but that could be a factor. If you're going to use modern gun storage lube, maybe you should clean with modern gun solvents as well.
 
Traditionally no solvents are used while cleaning sword blades. The blade is wiped free of old oil with washi paper (although microfibre cloths are used by sword dealers in Ginza), fine ‘uchiko powder‘ is applied to soak up any remaining oil and wiped again (uchiko is abrasive and degrades the polish over time - microfibre cloths negate the use of uchiko and preserves the polish!). I used 100% alcohol to degrease the blade as per the Jenolite instructions.

I suspect the cohesive/adhesive properties of the oil become significant when placed onto highly polished steel. If the oil is more cohesive it will tend to form beads whereas a more adhesive oil will tend to form a layer on the surface. Break Free CO Collector is noticeably thicker than choji oil (a light molecular weight mineral oil with a little clove oil for a nice fragrance). I’d need to ask an expert on lubrication to verify this idea, or otherwise.
 
As a lifetime user of Japanese blades I would not use choji on my weapons. Never get those cheap uchiko balls. My sensei who was also a renowned katana kantei would get me decent uchiko. A small earing box with a strip of chammy leather. Just a few drops of a light gun oil on it. A quick wipe after my daily practice.
 

Attachments

  • embu3.jpg
    embu3.jpg
    55.2 KB · Views: 19
I think you’re conflating the storage and care of a frequently and regularly used sword with one that is placed in longer term storage. A frequently used sword

When a sword is made, the polisher is paid handsomely to render it’s surface into a beautiful mirror-like surface. Then the traditional advice is to pat and shake abrasive uchiko powder (pulverised polishing stone) onto that mirror surface, in order to simply soak up old choji oil, and then rub it firmly all over the blade, denuding it of it’s beautiful (and expensive) polish. Over time this leads to another (expensive) trip to the polisher to have your dull blade restored to it’s former glory!

These days, we have much less destructive means of removing old oil, for example, microfibre cloths with their incredible wicking (capillary) properties.

Choji’s low viscosity seems to be perfect for oiling swords since it spreads itself over the surface rather than beading up. I’m sure there are other low viscosity oils that’d do the trick, too.

This book is contains incredible information on the Japanese sword and it’s care (just look at it’s Amazon reviews). Every swordsperson should own this and inwardly digest it’s contents!
5063D2AE-1DBD-4609-99F8-60B547B2457E.jpeg
 
I think you’re conflating the storage and care of a frequently and regularly used sword with one that is placed in longer term storage. A frequently used sword

When a sword is made, the polisher is paid handsomely to render it’s surface into a beautiful mirror-like surface. Then the traditional advice is to pat and shake abrasive uchiko powder (pulverised polishing stone) onto that mirror surface, in order to simply soak up old choji oil, and then rub it firmly all over the blade, denuding it of it’s beautiful (and expensive) polish. Over time this leads to another (expensive) trip to the polisher to have your dull blade restored to it’s former glory!

These days, we have much less destructive means of removing old oil, for example, microfibre cloths with their incredible wicking (capillary) properties.

Choji’s low viscosity seems to be perfect for oiling swords since it spreads itself over the surface rather than beading up. I’m sure there are other low viscosity oils that’d do the trick, too.

This book is contains incredible information on the Japanese sword and it’s care (just look at it’s Amazon reviews). Every swordsperson should own this and inwardly digest it’s contents!
View attachment 30570
For sure mine are to use not to store. Never actually saw a rust spot but I have had a black stain from constantly handing one to do noto.
 
For sure mine are to use not to store. Never actually saw a rust spot but I have had a black stain from constantly handing one to do noto.
That suggests you don’t own ‘art swords’. Art sword can and should be used occasionally, just like a Mercedes Benz 300 SLR Uhlenhaut Coupé, but you wouldn’t go to the supermarket in that Merc….not everyday…unless your an idiot!

That black stain is corrosion. You might want to try using better quality uchiko 😄😉
 
That suggests you don’t own ‘art swords’. Art sword can and should be used occasionally, just like a Mercedes Benz 300 SLR Uhlenhaut Coupé, but you wouldn’t go to the supermarket in that Merc….not everyday…unless your an idiot!

That black stain is corrosion. You might want to try using better quality uchiko 😄😉
It's not an art sword. Forged for specific use in my ryu. Drawing seven days a week things get worn and discoloured. Especially in tsuyu. Mine is han togi. Not full polish for display. Yes I could get the togishi to clean it up. He also covered my saya with same and covered it with a very thin layer of urushi. This was purposeful as now after lots of use it bears my fingerprints.
 
Last edited:
It's not an art sword. Forged for specific use in my ryu. Drawing seven days a week things get worn and discoloured. Especially in tsuyu. Mine is han togi. Not full polish for display. Yes I could get the togishi to clean it up. He also covered my saya with same and covered it with a very thin layer of urushi. This was purposeful as now after lots of use it bears my fingerprints.
No need for an expensive togishi! Just follow my guidelines above!😀
 
Back
Top