Finishing the front of a wa handle.

Matt Rochester

Matt Rochester

Joined
Nov 28, 2014
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So, I'm going to do my first wa on a little santoku soon and have a question. I am thinking of using a thin piece of copper/brass for a guard(if that's what it's called on a wa handle)and I know how to fit that. My question is if I wanted all wood with no guard then how do you finish the front? With a metal guard I can peen it if the slot is too big etc. Seems almost impossible with wood. Thanks!
 
I've only done one of these so take it with a grain of salt. But I highly recommend using a bolster of some kind or a thin piece of metal at the top of the handle. That way you only have to get perfectly fit on that piece in fact you can have the slot be a little bit bigger to Within a quarter inch on the front. That way you only have to be perfect on a quarter inch of material. Beyond that you just have to be very careful fitting and filing until it's perfect. Even with all that on the one that I did I used black bolster material and I dyed my epoxy black to ensure if I had any gap at all you wouldn't see it
 
If you cut a piece of 20 gauge copper, brass, silver, nickel, etc. to fit the tang snug and slide the bolster block against it, the metal piece is called a seppa. Thgius is very simple to do, and a good procedure for a beginner.

If you fit the bolster block with the wood showing on the front, you have to make it a snug fit, or the gap will be off putting. Using Buffalo horn (water buffalo) is the normal material for this, with African Blackwood a second good choice. The buffalo horn saws, files, sands, and polishes easily. Many use a thin piece of horn for the tight fitting part, and a thicker collar of the same horn behind it. The larger block can have a sloppier hole, because it won't show. make it a good fit at the top and bottom, but don't worry about the sides having a small gap.That way, you only have to make the thin piece a tight fit. When glued together with CA, sanded and buffed, the glue line may be invisible.


If using a one piece wood bolster with no seppa (the thin metal front piece), do this:
Cut the block of wood or horn and orient it so the grain is going from back to front. If you orient the grain up and down, it won't look right when done.
Next, mark the centerline where the slot will be for the tang. Mark the width of the tang on that line so you know where the top and bottom of the slot will be.
Drill two holes that are smaller than the tang just inside of the marks. Carefully cut a slit between them with a coping, scroll, or jeweler's saw.
From the back side of the bolster ( the handle side), use a 3/16" or 1/4" ball burr and open the slit up until it is about 1/4" to 1/8" from the front. Now you only have to file the last little bit as a close fit for the tang.
An alternate of this is to use a thin piece of wood and a thicker block behind it, as in the horn assembly above. They can be the same type, or contrasting. The front piece is almost always black (or dark).

Once the bolster block fits the tang, drill out the main handle block for the tang.
Square up the front of the handle block and the back of the bolster block.
Place superglue on the front of the handle block and slide it and the bolster together on the tang. Hold in place for few seconds, and then carefully slide them off together. Let dry overnight. You can now shape the whole handle, and install it as normal, using 24 hour cure epoxy (one hour cure at the minimum). There will be no visible gap showing. A good trick is to dye your epoxy to match your bolster ( almost always black).


Here is tutorial WIP I did a while back on a wa handle. The fancy stuff doesn't matter, as the construction and fitting are the same.
http://www.bladeforums.com/forums/showthread.php/916522-Yanagi-ba-BBQ-WIP
 
I used the slotted dowel method on mine and was happy with it. I don't have any pictures, but there are YouTube videos of it. It allows you to make most of the cavity with a drill into which you insert a dowel slotted to fit the width of the tang.
 
One other method is the laminated bolster. Carter has a good video on this one.

Personally I use a mill on mine and it works fantastically. I just have a little mini-mill and this is it's primary function other than drilling the odd corby hole.
I mill slightly undersized to about .35 inches deep or so, then mill the back side too. This allows you to use a standard drill bit to make the two holes meet. The mill slot keeps the drill straight, and that it the challenge with drill bits. They like to wander.
Then the tang itself is used as my broach to widen the slot to the right size. I leave just enough gap to allow for a thin layer of epoxy in the slot. It's easy to make the slot too wide, so you have to use care.

I accidentally found a new tang broach method a couple of weeks ago. I had the slot very tight and sticking the tang in, I had to tap the back with a small ball peen hammer to get it back out of the bolster.
This slightly mushroomed the back of the tang, and it turns out that little lip makes a great broach on drawing the tang back out. Thin shavings and you can size the hole very well.

YMMV
 
From what I can tell, on many of the Japanese made wa handles, the ferrule/bolster is a sleeve that fits over the inletted end of the handle, which means that handle wood is showing. On a lot of the custom made wa handles made in the West, ferrule is solid and the opening/slot is cut into in the both the ferrule wood and the body wood, not not the exposed body wood. More time consuming to make for sure, but generally cleaner looking. The slotted dowel method or the two piece methods either using a mortice joint or a "spacer"with the tang slot cut into it. appears to make construction fair bit easier. The dowel method also doesn't require you to cut the narrow slot the entire length of the ferrule as the back end of the "slot" is going to be a drilled round hole the didmeter of the dowel. With a metal ferrule, that might mean that the slot is only going to have to be milled like 1/4 of an inch deep that. The easiest looking methods that I have seen online seem to be the ones where you drill a"pilot" hole the full length of the ferrule with a bit the same size as the thickness of the tang, then go back and drill your dowel size hole from the back and them lengthen the slot out from the pilot hole with a mill,drill or router bit and then tune it up with little files if needed.
 
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i mill the wood much the same as i woudl a metal but in the case of wood i oversize mill the slot from the blade of the block then under size the slot on the front and slowly open it up till its a slip fit. from there i drill out the rear handle block for the rest of the knife tang. the pin in my WA handels pulls the woods snug up to the rear of the blade shoulder. with all parts under tension i grind 90% of the handle so i have less chance of messsing up the blade post glue up. once base shape is done i mark both parts of the wood for top and front side (that way you dont miss match later when working with the epoxy) glue up and clean up with 220 grit on the grinderr then hand sand 320 and 600 grit then what ever finsh need put on the wood depending on type
 
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