WIP - Sunahama Kotanto, kaiken meets aikuchi...finished!

@orangehero yes, good call...this is a detail of the wrapping technique that should be noted for the purpose of study, though i rarely show the private side...there is one on the page: http://islandblacksmith.ca/process/carving-tsuka-handle/ and i added it above to the tsukamaki post as well.

The samegawa meets along the centre of the handle on the ura side, the seam runs through the mekugi-ana from fuchi to kashira...

The ura gets all the crumbs of tsukamaki...but it is accepted to show the seam proudly there (on the private side, for the owner only...even when drawn it is mostly covered) rather than try to hide it somewhere else at the expense of functionality or one of the more important views...

ie.
if it were on the omote (public side), it would show when worn or on display...
if it were on the "bottom" (ha), it would show when worn or on display and would be in a high wear area...
if it were on the "top" (mune) it would be in a high wear area...so ura is the place!
 
islandblacksmith said:
@orangehero yes, good call...this is a detail of the wrapping technique that should be noted for the purpose of study, though i rarely show the private side...there is one on the page: http://islandblacksmith.ca/process/carving-tsuka-handle/ and i added it above to the tsukamaki post as well.

The samegawa meets along the centre of the handle on the ura side, the seam runs through the mekugi-ana from fuchi to kashira...

The ura gets all the crumbs of tsukamaki...but it is accepted to show the seam proudly there (on the private side, for the owner only...even when drawn it is mostly covered) rather than try to hide it somewhere else at the expense of functionality or one of the more important views...

ie.
if it were on the omote (public side), it would show when worn or on display...
if it were on the "bottom" (ha), it would show when worn or on display and would be in a high wear area...
if it were on the "top" (mune) it would be in a high wear area...so ura is the place!
Click to expand...


All that and if it were an untanned skin it would provide the structural support against the seams on the ha and mune edges of the tsuka as it does on a larger piece. That really isn't an issue in this piece but definitely is in a katana. That's also why proper cutting swords shouldn't use samegawa panels as is so common on Chinese katanas.
 
@Stuart right on...the most important...the strength and performance! i was so busy trying to describe the function from the exterior i forgot to cover the interior ha.

@Alex thanks, getting closer every day!
 
SBranson said:
All that and if it were an untanned skin it would provide the structural support against the seams on the ha and mune edges of the tsuka as it does on a larger piece. That really isn't an issue in this piece but definitely is in a katana. That's also why proper cutting swords shouldn't use samegawa panels as is so common on Chinese katanas.
Click to expand...

Doesn't the Ito provide some (much) of that support? Rather than the Same? Curiosity point only - not meant as a derail. This really is an incredible WIP.
 
@liamstrain thanks! I have always thought of the components as a system of interacting components from habaki back to kashira...the more i experiment and test the more i realize how carefully it was all thought out...i wouldn't give any one of them up on a katana...

the ito provides tensile and compressive strength, but having rawhide there as well (samegawa or otherwise) adds a stiffness and rigidity that ito does not provide...there are historical examples of katana の samegawa being replaced by metal panels, theoretically in areas where seaside moisture and humidity was too much even for rawhide to be a reliable stiffener (though there is some precedence aesthetically from tachi styles as well)...
 
@liamstrain :Ito is only cloth after all. If the wood cracked and the nakago broke through, there's no way ito alone would have the strength to stop it all from disintegrating. The same though is incredibly tough, tougher than rawhide and once fit, dry and glued to the tsuka core, then reinforced with the binding action of the ito... it's a pretty solid package. That some pieces would just be samegawa but never just ito should speak for the superior strength of the former over the latter.

There are many examples of tachi with just samegawa and the fuchi/kashira performing the binding tasks.

Personally I wouldn't want to use one without ito, that samegawa would tear your hand up.
 
Thanks to you both for the additional information. Great stuff! Is the samegawa or other rawhide also glued with the rice glue? or with something else?
 
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liamstrain said:
Thanks to you both for the additional information. Great stuff! Is the samegawa or other rawhide also glued with the rice glue? or with something else?
Click to expand...

Well, I scoured through all of my emails with Dave trying to find the answer for you and I can't seem to! I'm sure Friesen-san will chime in though...
 
Here are some images of different samegawa-kise:

k0jj.jpg
 
here's the kashima sisters checking in on samegawa wrapping and styles: http://www.ksky.ne.jp/~sumie99/samewrapping.html
and kensen~san: http://www.thejapanesesword.com/forum/viewtopic.php?f=29&t=62

a reference to the copper and iron panels i mentioned earlier: http://www.thejapanesesword.com/forum/viewtopic.php?f=29&t=70
and the answer to a question about using cow rawhide instead of samegawa: http://www.thejapanesesword.com/forum/viewtopic.php?f=29&t=165

@liamstrain yes, rice paste glue between wood and rawhide, urushi on the outside if it is used...normally i would use rice glue but in this case all the interior gluing for the tsuka is rice paste and the exterior is waterproof wood glue, though i found the bond strength to leather to be only slightly higher than sokui...

@gregorio much appreciated!

@watanabe thanks! looks nicely illustrated, what is the reference from?

...anyone have a historical example of a tanto without ito with a wrap and a half of samegawa? (ie maedaregise vs marugise) ...would like to see if it was ever done, though i can see the difficulties of making a smooth transition and getting a proper bond to the top side of the samegawa.
 
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Depending on the condition of the blade, the previously used stone is repeated again to ensure there are no new scratches from the workshop and then finer and finer stones are used to complete the finish. The last steps are carried out with Japanese waterstones which cause the hamon and other steel activity to show up against the body of the blade. The blade is carefully cleaned and oiled frequently for the first few days after polishing.

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After a repeat of the 600mesh/25micron (fine) DMT stone at a 45 degree angle, a 1200mesh/9micron (extra-fine) DMT stone is used straight in line with the blade. All stones after this will be used in the same direction.

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A Japanese waterstone forms a slurry like fine clay with suspended particles in it, water (with a little baking soda to combat rust) is used to control its viscosity and how much stays on the stone during use.

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As soon as the Japanese stone starts to work the hamon becomes visible. A more technical approach could show this hamon much differently, but goal of this polish is just to give a simple and honest look into the heart of the steel.

kaiken-kotanto-aikuchi-155.jpg

A different angle of light. Some very interesting activity surfaces, near the tip on the omote side there are double-lobed shapes fanning out under the place where the clay lifted slightly during the quench. One of them extends back almost to the centre, above the hamon, and has a similar area mirroring it on the ura. These areas are almost imperceptible in the final polish, but show as glimmers light in another direction from the surrounding surface and hamon at certain angles.

kaiken-kotanto-aikuchi-156.jpg

This is a finer synthetic Japanese water stone. The slurry is grey from the steel mixing in with the clay as it comes off the blade.

kaiken-kotanto-aikuchi-157.jpg

A natural stone gives a nice final finish due to its slight variation of hardness and grit size. The blade will be carefully rinsed and cleaned and then oiled. My favorite part of this hamon is the way it gets pebbly, like fine sand washing in a river, right as it turns back at the tip.


more of the story: http://islandblacksmith.ca/process/togi-hand-polishing/
...final assembly is nigh!
 
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Beautiful. Looking forward to seeing it all cleaned up!
 


This piece was named for the way the natural spalting design of the saya is reminiscent of an ink painting of waves washing on a sand covered shoreline. It also commemorates the fact that the woods used for the handle and saya are among the most recognizable of the West Coast woods, and the common experience that ties it to its final home over on the East Coast.

The concept was to create a very small kaiken style tanto but to bring in the proportion and aesthetic of a formal aikuchi mount so the knife could serve well as in daily use and as a display piece. The design was a collaboration with the client (Evan!) and, in addition to meeting the small size requirements, includes elements of one of his favorite aikuchi styles and is made from Vancouver Island native woods which hint at another area of his aesthetic study and artistic pursuit.

The blade construction is muku with a hira-zukuri profile in yoroidoshi proportions and a ko-maru mune. The blade is 3" long, overall length is just over 6.75", and the overall length when sheathed is just over 7.5".

Specifications

Nagasa: 2 sun 6 bu (78mm)
Motohaba: 6 bu 3 rin (19.2mm)
Motokasane: 1 bu 8 rin (5.5mm)
Nakago: 2 sun 3 bu 5 rin (70mm)

Construction: hira-zukuri, ko-maru-mune
Sori: straight/slight uchizori
Hamon: notare, o-maru sagari, slight hakikake (if you are an authority, please correct me on these...i'm not so versed in the nitty gritty of martenisite appreciation yet)
Nakago: futsu, kuri-jiri, one mekugi-ana, signed near the tip
Mei: hot stamped Crossed Heart logo

Material: Reclaimed sawmill blade steel, reclaimed copper water pipe, Yellow Cedar, Pacific Yew, samegawa, spalted Alder firewood, Cocobolo chopstick

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kaiken-kotanto-aikuchi-5.jpg


kaiken-kotanto-aikuchi-6.jpg


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a few more photos here: http://islandblacksmith.ca/2014/04/sunahama-kotanto/
and the whole process of making it starts here if you care for a review: http://islandblacksmith.ca/process/forging-a-tanto-blade/

also:
3.03022 cm
= 0.1 shaku（尺）
= 1 sun（寸）
= 10 bu（分）
= 100 rin（厘）
 
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