Japanese Style Kitchen Knife Build

I've been working on a knife which I hope will resemble a Japanese kitchen knife of some sort.
I haven't decided whether I should call this a long petty knife, a slicing knife (sujihiki) or a gyuto. It is going to be made of high-performance stainless, so I have chosen CPM 154 and I have a piece of 3/32" x 1.5" x 13". Normally a gyuto will be around 2" deep at the heel, so this is a little lighter, more like a long petty.




The little portable band saw makes easy work of getting the profile roughed out.




Bringing it back to the line with some 60 grit.




Really rough grinding with 60. One thing that's been decided is that it's going to be double bevelled.



A bit of hand sanding and it's looking better.



Some more hand sanding and I'll prepare to heat treat it then finish the grinds.


Hey it's fun to learn and try new things.

I know the purists would say that I should have made this from carbon steel and patina'd it up real good, but I like the idea of inox in the kitchen.

To be continued...

Dan

 

Tonight I got the wa finished up. -- Note I am using more of a thumbnail size images as this gets thread will get pretty image heavy after a while. Clicking on an image should open a larger version.

I am not using horn as I don't have any, so I will use some ebony in lieu.
The components are ebony for the ferrule, 1/16" brass as a spacer and stabilised maple burl as the handle.


Mark each piece for center and dill.


First pilot drilling with a small bit, 1/8" or smaller.
This should be no larger than the knife thickness at the neck. (just in case you don't want to expose the dowel like I want to.)
Pilot through the centres of all the pieces.

To check the faces for surface contact. I used a piece of 1/8" dowel.



Check the depth of the tang as we're going to have to drill in this deep to the handle to fit the tang.


Drill the pilot holes out to 7/16" or whatever size dowel you are using. There will be some glue going into the hole, so a little loose is better than pound-on tight.


Using the drill press, drill into the handle block just past the required depth to accommodate the tang as outlined above.


Insert the dowel and mark for cutting.


For this build I used Permatex 84107 30 minute high strength epoxy.


Make sure there is lots of "splooge" (excess to fill in any minor gaps)


For clamping, I end clamped with about 50 lbs force. I used a key ring so I could clamp over the dowel. Let this set up for an hour or two.


After the epoxy has set, at take to the belt sander with some 80 grit aluminum oxide. Working here to square up the faces


Once the faces are clean and the block is square (as in 90° angles) it's time to mark off for the facets.



I used a tri-square and an X-acto knife to scratch the lines. This will help guide my eye in making the four facets.


Here I am making the facets. Four will make an octagonal handle.
I used the flat platen and a 60 grit belt.
Cutting one end then the other, and meeting them in the middle of the handle.


This is a shot of how it's looking so far.

 

Here is how I "milled" the tang slot in the handle.
I don't have a milling machine proper but a drill press and some patience will do.
I use the vise here as it needs to be kept nice and square as it's going in over three inches.


I drilled 7/64" in three spots along the line.


And gently removed the material between the holes.


Test fit the tang into the slot and repeat. Switched to a 6" long "aircraft" bit and repeated.


Some needle file action may come in handy too.


Once close to fit, heat the tip of the tang with a propane torch and press it all the way in.
Smoke, burn etc. I wanted to do this before the heat treat just in case.


This is sort of what the end result will be like. The blade needs to be cleaned up and heat treated so that's next on the agenda.


Thanks for watching!

Dan

 

Very interesting Dan! Keep posting.

 

Will do Roman. I really enjoy as this is lots of new ground for me.

I painted the blade with Condursal Z1100 and a cheap brush. It's green and smells like nail polish.
Let's give it at least a half hour to dry.


The oven is getting up to temps. The thin blade doesn't need a long time to soak. I gave it 10 minutes after hitting 1060°.


Here's the blade moving over to the plates for quench after being pulled from the oven.
It was white when I removed it from the oven and cooled to this colour by the time I got my camera turned on.


Plate quench is two 1/2" thick tinned copper plates and a squeeze in the carpenter's vise.


The blade looks a little scaly, but this is supposed to brush off.


Quick check for warp. Looking good for 8" of blade of 3/32" stock.
Not a lot of time to waste...into the tempering oven.


Tempering at 175°C (350°F) for a higher hardness. Trying for around R60C.


In the morning we'll see how the paint comes off.

Goodnight!

Dan

 

Is it a gap there between blade and bolster? How are you going to fix that?

 

Yes, the dreaded gap. I haven't finished the blade yet. When I do the install, any gap will be filled with epoxy mixed with a little saw dust of the dowel wood.

 

This is not an ideal solution. The gap will still be visible... But let's see what you get at the end.

 

Dan, does the Z1100 work better than the stainless foil ?

 

Roman, can you suggest a fix for the gap? I have brought the face back about 2 millimetres which improves things a bit.

Cal, the Z1100 seems to work okay. I still don't have any product literature on it, so I can't say if I did it as per manufacturer's recommendations. It comes off easy enough with scotch-brite.

Happy Father's Day!

Dan

 

Dan, there is no fix for the gap. It has to be made without gap in the first place. What I would do if I be you to fix it? I would take 2-3 mm brass plate and make a very nice, tight fit (in my KITH WIP I explain how I do that). Then I would glue it in front of the handle. But this would change the look. Other option is doing same thing with 2 mm piece of ebony, then thin sheet of brass, then handle. Basically, you need to make a new front for the bolster.

 

Back again, mid-year inventory at work so it's been pretty hectic. I did get a chance to do some more work on the knife, mainly grind, finish and get the handle on.

I am grinding this flat, dual bevel. It's very hard and knocks the ceramic belt down pretty quickly.


This is a pic of the bevel grind in progress.


Once the thickness at the cutting side is close to 0.02" (0.5mm) I'll do some hand finishing.


On the flat with a block and sheet sand paper to 400 grit.


I like to give it a good buff to help identify any areas that need a little extra finishing work.


Tweaking the handle to fully receive the blade.


Heating the tip of the tang with a torch before pressing it in all the way.


This is the fit. I soaked the handle in Minwax Chestnut stain and it's looking darker now.
I really liked some burnt chestnut wa I've seen. The maple is darker brown now for sure.


Electro-etching my logo from stencil


A shot of windex and clean to remove the electrolyte.


Preparing to mix some Acraglas.


Gooping it in the hole and on the tang.
In hindsight, I should have wrapped the handle with cling wrap as a little epoxy got on there.


Let sit for 24 hours...


Only time will tell how it cleans up.

I'll be back to check on this tomorrow.

Dan

 

After some cleanup of the handle I put the edge on the blade with a ceramic belt.
I then rubbed the blade out a bit with green Scotch-brite.


The blade and handle get a buff with Renaissance wax.


Some shots from the light box.





One correction. The steel I used was in fact 154CM, not CPM 154 as stated in the beginning of the project. I will be making a saya for this now. That will be coming soon.

Hope you enjoyed this walk-through. It was my first wa. Judging from the comments from friends and family I will be making more.

Stay cool!

Dan

 

Saya. Oak.

 

Hi Dan. I am going to try and make a few kitchen knives for Christmas presents and really like this build so I am going to use it as my go to. My biggest question is what is the purpose of the dowel? I have looked at other handle info for this and haven't been able to find an answer.

 

The dowel is used to hold the different handle pieces handle together prior to fitting the tang in. Relying on butting and gluing the handle components together without some internal support would likely end in failure.

Best of luck!

Dan

 

Thanks Dan!

 

Dan
Could you not slit the dowel most of the way down the length with a saw before putting it in the handle being careful to get what will be the outside end nice and tight to the blade.
A hacksaw would work and sometimes I put 2 blades on the hacksaw at the same time to make the slot wider. A little filing may still be required for the perfect fit but at least you are starting with square sides. Just a thought.
Frank

 

Yes for sure. I've seen it done where the dowel is ripped with a saw before gluing in. After everything is set, the tang is burned into the slot. The drawback of that method, say in the case of an octagonal wa, is the handle must be fashioned so the faces align with the existing slot in the dowel or the blade/handle orientation will be off. I sort of covered my ass by making the faces of the octagon first, which for me was the hardest part. The idea being make the octagon as best I could, then using those faces marked and made the slot line up parallel/perpendicular.

Dan

 

I was thinking more of glueing the slotted dowel and the blade in at the same time so you could align the handle when you insert the unit.