I’ve been away a bit due to a reoccurring hand problem so I am basically on light duty until that is resolved, so in the meantime I am doing a lot of little stuff here and there and one of the activities is getting myself caught up on my polishing.
I am currently busy polishing a Kogarsu Maru Tachi made from steel that I smelted myself using the locally available ore from my area, via direct reduction for the smelt. For the ore itself I used Nevada Desert magnetite, which I obtained from the sands that's all around here.
During the smelt I added a small amount of graphite to the mix in order to raise the carbon content. The bloom came out really clean, not many voids and felt very "heavy" mass wise for its size... It was flattened then it was triple cut and re-welded using triple cuts each time for 5 times in order to refine the grain structure. Worked smoothly and was very "solid" under the hammer. No problems with crumbling or anything. Welded great..one of the smoothest refinings I have done so far.
It sparked like a 60 t0 70 pt C steel but the sparks were very "white"..not the golden/reddish yellow like most carbon steels...
The sword blade was then forged out of this material, rough shaped under hand hammering, rough ground and then shaped, the two Bo-Hi started and then heat treated. ( I’m not going to tell you, yet,, how I got that little arrowhead shaped termination at the Kissaki, as that will in book No. IV. I got that idea for that type of termination from several pieces I have seen what I was doing research for a book IV).
The blade was clayed using A P Green High Al furnace repair/cement with concrete tie wire used to hold the clay in place during yaki ire. The quenching medium was warm brine ( my own mix of sodium hydroxide and ammonium nitrate, which is basically caustic blue salts) at a temperature of 265°F. Horizontal quench.
The blade came out of yaki ire with no cracks, warps or bends, and with a graceful amount of sori. I then started the polish after I scraped clean and base polished the Bo Hi…
While I was polishing I noticed that the Hamon was taking a much "smoother finish" than the unhardened areas of the blade. Now this is not all that unusual, as it is harder but for some reason the colors were little “ off” than what I usually see, more "darker grey", almost a bit "greasy" in colour in the softer areas.
This was becoming more noticeable as I progressed up in the polish into the finer grits. Once I got to 2500 grit, I did a very short etch in ferric chloride for approximately 30 to 45 seconds. Upon the removal of the blade the entire surface was black, which for me is more or less normal for the way I work.
As I was wet rubbing out the blade with 2500 grit wet/dry paper to get off that black crud I noticed that the Hamon was very smooth and silvery white with a cloudy transition line between the hard and soft areas of the blade (Shibuchi line) The softer area displayed a surface that had an "open" grain that looked like either some flavour of wrought iron or Wootz. Now I have never seen this happen before and I am stumped, maybe alloy banding but I doubt that....
Now let me backtrack a bit, the area where I obtained the magnetite is downwind a little ways from Ti-Met, which is a titanium foundry located here in the Henderson area. Now since titanium is paramagnetic, I feel that some of that material may have piggybacked onto the magnetite‘s surface, being picked up along with it as that is the only way it could have been “picked up“, or maybe my adding the graphite to the smelt may have caused the effect illustrated in the below photographs. Maybe it’s a little both, I do not know.
The finish was totally smooth and hand rubbed out to 2500 grit before the etch.NO scratches visible, almost to a full mirror polish.
The resulting finish after the etch, on the non-hardened areas of the blade is very similar to, at least to my eyes,as I said before, WI or Wootz. Now I was wondering if any of you fine folks have any idea as to what happened and why I’m getting this effect and result. I’m also wondering if I could of accidentally violated Mr. Daniel Watson’s so-called “Techno-Wootz” patent. Either way I am at a loss as to what happened either during the smelt or the hardening process. So does anyone have any ideas at all?
I was thinking as I am continuing to study that the grain looks alot like a wrought iron type of structure, but then,thinking a bit more why wouldn't the grain then be visible in the hardened areas of the blade as well, instead it being only seen in the un-hardened areas?
Here are the specs...
Nagasa: 32"...(measured from habaki to kissaki)
Ha-Mune (Back edge) length is 14"
Bo-Hi..One is full length (down the shinogi-gi) and the other Naginata-Hi..running along the Mune "back edge"..."Diamond Point" terminus of the full length Bo-Hi..which as I said I WILL explain in book IV...wha-whah -wha ha....heh heh heh....the hard part was getting it down to clean metal and polished....
Blade type: Kograsu-Maru AKA "Little Crow"....
Tsuka length 14", black samegawa under black and gold chevron silk tsuka-ito. Kashirae theme- Temple Lions/Chi-Chi Lions/Fu Dogs.....they are called by all three names..same critter...
Siya: Magnolia wrapped with split rattan for the first 1/3 of the siya length...Amber Horn siya fitings and the whole finished in red gold leaf under black cracked lac.
OAL: 47 3/8"...The Tsuka-Ito is black base with gold chevron woven in silk...I love that ito....makes even my work look good....
Any and all ideas are welcome so enjoy the photos.
Thank you
JPH