Saya construction

The saya is the scabbard of a sword in Japanese. The saya has a beautiful finish to it and is very often so highly lacquered that one might think it was plastic! It is, in fact, traditionally made from magnolia (ho) which is easy to work, has very little sap and is said to have oils wihtin it to help preserve the blade (An introduction to japanese Swords, I. Bottomley). 

I found a very interesting website outlining the main processes of making a saya:

• Kidori & Nakadoshi: Cutting & Splitting the Blank
• Kezuri-awase: Planing the Inner Surface
• Kaki-ire: Chiseling the Space for the Blade
• Norizuke: Gluing the Two Halves Together
• Arakezuri & Nakakezuri: Rough & Fine Planing the Outside
• Mekugi-ana-age: Drilling the Rivet Hole
• Shiagekezuri & Shiagemigaki: Finish Planing & Finish Polishing

Usually the hilt (tsuka) is also made from magnolia wood. I believe the ho wood is cut from the Japanese magnolia or Magnolia hypoleuca (possibly Magnolia liliiflora).

The saya is an important part of the sword in iai. Correct usage of the saya helps the drawing of the sword rendering the iai-to a two part weapon: sword and saya.

Menuki

The menuki is a sword hilt decoration found on Japanese samurai swords. It is fitted to the handle (Tsuka) over the (usually) ray skin and under the handle bindings called 'Tsuka-Ito'.

This ornament hides one of the mekugi or holding pegs which are driven through the tsuka joining it to the tang of the blade. It also affords a little 'grip' as this protrudes slightly into the palm of the hand ad I find helps 'locate' the left hand. The left hand is important for cutting in iai.

Nice schema on wikipedia of Japanese sword:

http://en.wikipedia.org/wiki/File:Katana_(common_shema).png

An interesting article here about shortening the tsuka which also shows some construction of the handle.

Koiguchi Repair

The habaki of the iaito is the collar of the sword which fits snuggly into the koiguchi, or the mouth of the saya. It should because of this tight fit, when fully sheathed, prevent the sword from tipping out and requires a push from the thumb to start the drawing process.

After much practice the sword feels loose in the saya as the bottom edge is worn away. To maintain this tightness a small piece of wood needs to be glued in place. This article outlines how I went about my koiguchi repair.

Firstly I found a nice piece of veneer: mine was cherry, a bit thick probably at about 4/5mm but I'd rather too thick than than too thin!

I cut a wedge shape out of the veneer and glued it in position with PVA wood glue and left it to dry. My tip for gluing is to use a pin! Squirting it directly form the bottle may end up in a blobby mess on your tiny bit of veneer!

Roughen the inside top edge of the saya and tap out the dust. Glue it in place and leave. Once it's dry simply use a file to bring it down to the desired level: remember it should help maintain the sword in the saya without it being too difficult to push out. Mine is a bit too stiff at the moment so I'm working it in slowly with some drawing practice.

Links:

http://www.sayashi.com/project%20pages/koiguchi.htm

http://oregonstate.edu/groups/kendo/dojo/parts.html