April 20, 2016
Japanese Hammer And Handle Fitting (Part 2)

Japanese hammers with their handles are fitted together without the use of any adhesive or wedges, instead only relying on compression joint. The hammer head has an internal taper which forces the tenon to be compressed as it gets past it. When the tenon gets past the taper, it will become noticeably smaller. After that, the tenon would be allowed to swell back to its original state by adding a bit of water or preferably oil to it. Once it swells back, it forms a strong joint.

Tenon in the hammer head mortise, just before the taper starting point

Handle fitted in successfully, only about 3/8" in, over the course of the next few days, I'll then progressively drive it further into the head.

The handle receives a taper from the bottom to the neck

Added a bit of detail on the neck

Japanese hammer usually have a curved handle. This helps the user to identify very quickly which side they are using when they pick it up.

Happy reunion, joining the family of gumi handles

#hammer #genno #daruma #gumi #inoue #井上刃物

April 19, 2016
Japanese Hammer And Handle Fitting (Part 1)

Started on this little side project on fitting the gumi handle to the hammer head. Even though I've did this several times before, but this time round I'm slightly more excited because this is my first time working with raw material like this. This gumi branch came all the way from Japan and I can't afford to mess it up!

The tools that will be used for fitting and shaping the Gumi handle to the hammer head

Cross section of the gumi branch after paring it clean with a chisel. This makes it easier to do the markings and locate the center line.

Removed the bark so that I can put a pencil line around to mark the depth of the cut for the tenon

Sawing the tenon

After the tenon is cut, I started to use the plane to do some rough dimensioning. It wouldn't be comfortable to hold if the handle is crooked or lopsided.

Removing the bark with a kiridashi before shaping with other tools

After initial shaping with the spokeshave. This wood finishes very nicely even without the need of any sanding.

'Killing wood'(木殺し, kigoroshi) on the anvil, using a hammer to make a hammer. This is a good example of how the convex side of a hammer is used for. The convex side can compress wood fibres on the oversized tenon by repeated tapping on the anvil. The compressed tenon would then expand back to it's original state in the housing with the help of some water or oil.

After repeated tapping on the anvil, the tenon from oversized becomes much smaller.

#hammer #genno #daruma #gumi #inoue #井上刃物

© 2014-2017 Shibui Furniture Collective