First handle and KU removal

[AT5760]

A few weeks ago, I decided to buy a Tosa nakiri and bunka as project knives. I wasn't exactly sure what I wanted to do with them, so rather than come up with a plan, I decided to just dig in.

Here's what the nakiri looked like when I purchased it.

The first thing that I recognized was that I didn't like the KU finish on this knife very much. So I decided to remove it.

 

[AT5760]

I started on a 300 grit stone. It went very slowly and there were a ton of low spots on the face of the blade. So I wrapped the handle in a ziploc bag and put it into a pot of boiling water. Then I clamped the blade to a sawhorse and tapped on the handle with a hammer using a scrap wood block. The handle came right off I switched to 150 grit on my orbital sander.

This is where I made the first of many mistakes. I applied too much pressure when sanding and got a couple of deep scratches on the blade face. I moved from 150-220-500-1000. After the 220, I switched to hand sanding. Next mistake was just grabbing the sanding block that I use for drywall instead of a hard block. Lesson learned.

You can see there are still plenty of scratches, as well as a few nicks and hammer marks. The bigger issue, however, was that I wrecked the shoulders. I suspect that there was some concavity to the blade face initially and sanding to remove the KU led to me flattening the shoulders quite a bit.

 

[AT5760]

Once I was done with the KU, I attempted to flatten the bevels. You can see that I wasn't completely successful. This weekend, I'll likely go back down to the 300 grit and see if I can get rid of the remaining low spots.

Since the handle was off, I decided to make one. I already had a ton of respect for the guys and gals that do this professionally, now I have more. Let's just say I'm not a natural woodworker. It was fun though, and I'll probably do it again.

I picked up a piece of maple from the local woodworking store ($2.99) and got to work.

I don't have a table saw, band saw, drill press, router, etc. So, I drilled holes for the tang and tried to connect them. Unfortunately, my neither my 1/8 bit nor my 5/32 were long enough. So, I used a 3/16, which is oversized for this knife's tang. That led to a pretty big gap. Oh, I also put my drill at too much of an angle in trying to clear out the whole. That's why you see that green blob on the spine of the handle. I filled the hole with a mix of CA glue and touch up paint from my wife's old Subaru Outback.

Shaping the handle was done primarily with a hand plane. Lots of lessons learned here. The taper is too sharp near the blade, and I ended up with some weird taper toward the back. If you look closely, you'll see plenty of nicks from the plane. Did I mention that I'm not a natural woodworker? Once I had the basic dimensions for the handle, I sanded it down to 220 grit and put on a few coats of Minwax tung oil finish - not actually tung oil. Another lesson learned.

Fitting the handle was very easy given the massive hole that I made. Watched James video on hot glue installation - at least that worked like a charm.

Here are a couple of photos. I don't think I'm done with it. Maybe this weekend. Then I can see if it actually cuts.

 

[Taz575]

I have a few of those cheap Tosa knives. Great practice pieces and they usually take a wicked edge, too. Good way to learn about thinning, polishing, kasumi finishes, etc!

 

[Taz575]

Home Depot and hardware stores often sell longer drill bits, like 12" long. I use those and cut off the shaft end to make them around 6" long to drill deeper holes in handles if needed. Some stores like WoodCraft sell wood needle rasps that make quick work of connecting the drilled holes and there are some newer broaches on the market now that I want to check out. I used JB Kwik Weld to fill in the gap around the tang since most of the holes were larger than the needed tang diameter. Many of those tangs on cheaper knives aren't straight/flat either, so a bigger hole gives you more room to line things up better! Keep plugging away at it!

 

[AT5760]

I made a second handle this weekend, this time for the bunka pictured in the first post. Things went much more smoothly and I think the finished product is a significant improvement. The handle is probably to large in diameter for the size of the knife that it is on, but it is extremely comfortable to use.

What did I do differently? First, I went a lot slower when planing down the handle. That led to fewer gouges - none that I couldn't easily sand out - and a better proportioned handle. I got a longer bit, that led to less work with the files. I used the milling attachment on my Dremel to make the initial tang opening. You can see that the fit is much tighter than the first handle. Because the tangs on these knives are pretty uneven, I'm happy with the fit.

The handle is macacauba. I'd never heard of it before, but it wasn't very expensive and the guy at the woodworking store said it was decently workable. It's definitely harder than maple. Though I've only tried a few different handles, (ebony, ho, maple, cherry), this wood is really surprising. Sanded at 500 grit, it has a great grippy quality when wet and a certain warmth to it. Anyone else ever worked with it?

To anyone that has read this far, I'd love some tips on flattening the bevels and whether it is worth it. And what that may do to geometry on an admittedly roughly finished knife. This bunka is actually a pretty good knife and took a really good edge pretty easily.

 

[Robert Lavacca]

I’ve been there man! I bought a 180 shiro kamo nakiri a while ago. The KU was kind of crappy. Would come off while cutting food. I decided that I was going to remove the KU, flatten the bevels, and use the knife at home. Also practice polishing. Removing the KU left me with the same things on the face of the blade. The sanding job I did wasn’t horrible but it wasn’t great. The knife looks pretty crappy these days but I use it at home and I use it to test out Jnats. Even did a subpar job on the bevels too. As crappy as it can be to make these mistakes sometimes, it’s how we learn. Now when I thin a knife, I always try to make sure I am trying to keep as crisp of a shinogi line as possible and that i’m not scratching the actual face of the knife.

 

[inferno]

to flatten the bevels without it taking an entire day or so, i recommend a 220 stone like the shapton pro or the glass, whichever you find cheapest/easiest.
they get the work done. you will probably have to flatten the stones as you go. unless you try to use the whole stone and spread the wear that way.

shapton pro 120 needs really high pressure to work so dont get that one. the sigma 240 digs very deep scratches that needs to be followed up after.
diamond plates tend to wear out when doing flattening jobs.. and the scratches to remove are ultra deep!!

or just tape some sandpaper to something flat and pretend its a stone.

 

[cotedupy]

Great post! I'm similarly not a natural woodworker, have very few tools as well, so most of the things I do to knives involve this kind of 'improvisation'.

Have also got some Tosa blades on the way, and was wondering about taking off the ku finish, so this is very helpful And frankly I think your Nakiri looks ace (even if there are things you'd do differently next time).

 

[cotedupy]

And personally I wouldn't bother flattening the bevel on that bunka. But if you want to I'd agree with the above - around a 220 stone, I personally use a cheap oil stone for that kind of thing.

 

[ModRQC]

I can appreciate a good Kurouchi Down! thread...

Good work and have fun!

 

[Taz575]

I only have a couple KU knives with KU left on them. Most meet the belt sander!

I have a mioroshi deba with the KU still on it and a tosa 210mm gyuto and 210mm petty with the KU still on them. I use the 210mm petty rarely and the gyuto and deba are in a box somewhere. I find KU means wedgey monster all too often! I use them to practice/try kasumi finishes and as beaters to remind myself as how well the other knives perform!

The only exception is Shigeki Tanaka Blue #2 KU Nakiri. That still has the KU on it and is wickedly thin. His 210mm Blue #2 KU gyuto I had was super wedgey until it met the belt sander for a full regrind.