Shigefusa 270mm kasumi yanagiba with custom, by me, desert ironwood handle

14 Nov 2011

Handle and saya on Hiromoto sujihiki


A great sushi Chef in New York sent me a Hiromoto sujihiki blade with a block of stabilized spalted Hackberry wood that he wanted to have made into a handle. He also requested me to build a matching saya for the handle, but as soon as I saw the handle block I new I was in for a real challenge. The handle block is one of the most dramatic pieces of wood I have ever seen, and judging from the weight of the block it must have come a long way in the deteriorating process so allowing the stabilizing liquid to really soak through the wood. Challenge was to find wood for the saya that was not stabilized but still solid and spalted or figured enough to match the handle.

The blade is a Hiromoto san mai kasumi sujihiki wich has been etched (by Dave Martell?) to bring out the dramatic lamination line between the core steel and the soft cladding. The cladding had gotten an almost shimmering surface from the etching which stood in great contrast to the almost black core steel. My first thought looking at the blade and the handle block was that this would going to be one dramatic looking knife when finished.

Spalted hackberry wood - stabilized block, and the old handle
As soon as I started working on the handle block it soon became very clear to me that I was in for another challenge. The wood was so hard and dense that I had a really hard time working it. Both cutting, sanding and grinding was a really tedious process and it ate my sanding paper like it was made of wet newspaper. What was this wood anyway, petrified? Stabilized with shot proof glass?

Searching through my stock of different horn material I found a really nice marbeled piece of cow horn with dark and tan stripes that would match up really nice with the colors of the handle. After working out all the pieces and sorting out the order of which to put them I was finally ready to glue everything up. I have found this a good way to do it as I do not have the time to think and fiddle around when glueing things up. The worst things that can happen in this stage is that the glue starts to harden in the middle of the process so that everything is glued up with skews and voids all over the place. You might be able to salvage the wood but all bolsters and spacers will be heading for the bin.
All handle parts lined up and ready for assembly

  
All parts glued in with epoxy glue








 

While the handle was curing I could start working on the saya. I had gotten a nice piece of spalted Sycamore thin lumber that was still all solid. It was sold as luthier wood, but it was perfect for saya material. After outlining the shape of the blade on the wood I cut out the pieces with the necessary extra space around for glueing and shaping. As the ink line was just on the surface of the wood I had to grind down the pieces to about the right thickness from the side going to be the inside of the saya. If I had done all the grinding of the saya after glueing I would risk to remove all of the beautiful inkline from the wood.
Outlining the saya on the spalted Sycamore
Profiles sawn out slightly oversized






So, with the coarse shaping done I could start working out the cavities in the saya to fit the blade. The cavities should be as small and evenly shaped as possible without clamping the blade, and it is wise to make a 2-3 extra mm of space for the tip of the blade so the saya will not break it off if the saya is dropped when the knife is inside. The cavity along the edge should be as even as possible to protect the edge by distributing the pressure of the edge along the whole length of the saya if you get impacts to the saya with the knife in and pin out. Bumps along the edge line inside the saya can easily chip your blade.


Carving the cavities for the blade - Baby steps!!
 
Regularly checking the fit


 
Drilling and carving the tang hole in the handle gave me my next challenge as the wood clogged my drillbits every 2-3mm of drilling even if I was using a hand drill and going really slow. The clogging seemed to harden instantly like super glue in the cavities of my drillbits making them almost impossible to clean up. It took ages to drill two small holes for the depth of the tang. The rest was done pretty efficiently using a tiny square rasp and a very narrow saw that I have modified for this special task.  
Getting ready to drill the tang hole



Tang hole finally done


 









After shaping the saya and handle I was now ready to fit it all together. The saya was too light colored to match the handle so I dyed it with a spirit based wood dye. After some tests on a piece of saya wood I found mixing two parts "grey oak" to one part "red mahogany" would do the trick. After the dye had dried up I sanded down the saya with #800 paper until I got just the right color. Then I saturated the surface of the saya in Danish oil which gave me the exact color and hue I was looking for. After 48 hrs of letting the Danish oil harden, I gave the saya a final buffing with a wax based wood polish to give it a nice and silky shine.

All parts finally ready for assembly - Note the very light wood in the saya

Next up was to glue the blade in place. I had made the tang hole very slightly oversized to be able to micro adjust the handle on the blade. I wanted to give the handle a 1-2 degree lift related to the blade to make it more comfortable to use over time.

All taped up and ready for assmbly


Handle glued in place



 









Even if I had a really hard time working the material for the handle, this was one of my most rewarding projects ever. Before I started I feared that the heavy handle material would throw off the balance of the knife, but it came out perfect with a balance point just under 1" in front of the handle. The handle wood is some of the most spectacular wood I have ever seen and it really accentuates the dramatic lamination line of the etched blade. I was pretty happy with how the saya turned out as well to be honest. To pimp it all off I made a matching pin for the saya using the same marbeled horn as I used for the bolsters. Note the dark stripe in the pin matching up with the ink line in the saya :o)





 
Well, that's all, folks. Thank you for reading. I am happy for any comments and suggestions to my work as usual, as your comments is the only way I can get better at what I am trying to do. 
 

PS! NO power tools were used for this project. All toos used, except for the sanding paper and a Japanese ryoba saw, are shown in the pictures. This was done partly because the handle material did not allow for the use of power tools and because I wanted to see if it could be done in a proper way without the use of powertools. It took more time, but I did not heat up the materials at all, witch will reduce the possibilities for cracks and warping.

4 comments:

  1. Woot!

    You my friend are insane! :)

    ReplyDelete
  2. superb job Harald. that suji looks awesome and one of a kind. Guess who the lucky guy :).......

    ReplyDelete
  3. I totally agree. This is truly a one of a kind piece. I hope you will enjoy it when it arrives back home. Thanks for a great challenge.

    H.

    ReplyDelete
  4. We found your weblog is very handy for us. When you keep going this perfect work I’ll come back to your site!
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    ReplyDelete