Hello and welcome to the continuation of the Japanese Tool Box build, part of a series in which a Japanese Tool Box, inspired by Chris Hall of The Carpentry Way, is created as a gift to my son.
In part IV of this build I will be attaching the caps to their handles. With these details complete, along with detailing of the handle I will be able to begin assembling the case. One of the more interesting aspects of this build has been how much time is spent before sub assemblies are created. That has given much meaning to the quality and thoughtfulness of the design, which is intended to be a functional joinery study.
To begin this portion of the work I started by creating the tenons, these are squared six sides and thicknessed to identical dimensions.
Setting those aside I move onto the cap and begin my layout by determining which of these will set along the inside edge and which will be along the outside edge. The difference being that those along the inside edge will be dovetailed into the handle, where those along the outside edge will be ‘Hell’ tenons, which are Jigoku Hozo in Japanese.
Now that my layout is knifed in, I begin preparing to cut the mortises. These are through mortises, but because I am removing a portion of the back of the cap to create a housing I am cutting these into a maple backer, not overly concerned with the backside appearance (as it will be cleaned up).
After consuming the espresso I’m ready to begin, please note I am not using a mortise chisel here. In order to cut these rapidly I will be taking the top layer at a low angle, a plain chisel is suitable for that, and just like with all Japanese chisels I do not pry with them.
The first round of waste has been removed from the mortise and this is the appearance at that point.
The center is nearly the depth I desire, and the steep sections are then chopped away toward the inside of the mortise.
The waste is once again removed and the mortise is now clear through.
On visible mortises I will typically choose a chisel slightly smaller than my markout to leave a little bit of room for paring the sides, that was done here so my knife marks are still visible.
Now all of the mortises are chopped out and I begin paring the sides to individually fit each tenon.
The tenons have been fitted I can begin removing the waste from the underside of the cap. This effort is to create a housing which will pull the case sides tight to the handle.
After this work is pared back, the cap is then test fitted onto the handle. After ensuring that it fits I will return to the chopping block to angle the mortise shoulders to allow room for the tenon wedges.
I check with a gauge to ensure that the tenons mortise sides are properly cut.
This will be critical as the markout is transferred from the cap mortise to the handle.
Now I begin work on the dovetailed tenons by marking out and cutting the lapped dovetails.
I put the waste aside as that will come in handy a little while later.
Next I transfer marks to my handle.
I’m using a marking knife, the reason I prefer a marking knife is that I know I can cut right to the side of the mark for an accurate fit. When using a pencil I always find my fit slightly loose. Next I am sawing the lines.
Quick shot of the tools I will use to excavate these half laps.
I start on my line, bevel down and resulting chop will remove a good deal of the wood that has been sawn out.
I then set the chisel on the waste, with the bevel toward my line and chop away at the waste to loosen it up, and finally chop the edges to sheer the waste making it easier to pare away.
I chop my line with a wider chisel, and finally use the bachi nomi (dovetail chisel or fishtail chisel) to pare the corners. This can be done without it, but its quicker just to have one handy.
The resulting cutout is looking good.
I don’t mind minor overcuts here, because this part will be hidden from view. If these were going to be exposed I would be certain not to overcut and to mark my shoulders accurately the first time. It’s best not to see those sort of errors on a finished product. A test fit shows accurate work without additional fitting and the tenon is glued in place.
Two more and we’re ready to move on.
I’ve now cut out the mortises for the Jigoku Hozo (hell tenons). In researching the work before hand Chris Hall has pointed out that it is critical to ensure accurate mortise depth, smooth sides and accurately cut angles. If the angles are too tight the tenon will never seat, too wide and the tenon will be loose. I have set my sliding bevel to the desired angle and I’m matching that angle with the flat of my chisel.
The resulting mortise now ready to receive the internally wedged tenon.
The tenon has been cut and fit for wedges and the wedges fine tuned with a hand plane to ensure that they’re the correct length and thickness. You may recall those wedges being the waste from the half lap dovetails.
Fingers crossed that my work up to this point is accurate, if it is not I will be drilling this out and starting over.
The tenon is now seated and tight, all efforts to wiggle it are fruitless. The finished effort is quite inconspicuous.
Now I’m ready to test fit the cap.
Looks good. I put the cap aside and I’m ready for the final work on the handle, cutting a finger groove that will make grasping the handle slightly more comfortable. I’m deviating a bit from plan here as Chris’ toolbox has a cutout for the handles.
This can be done with a molding plane, first cutting an angled groove and then following along with the plane, which will then track nicely in the groove. It can also be freehanded with a gouge and that is what I’m doing here. The slight texture will be appealing to me on the underside of the handle.
A finely finished edge and working along the grain will result in a very smooth finish. A router table would make a more accurate groove, however it would require sanding after the fact, I can avoid all of that here.
Last I chamfer the outside edges and cut for wedges, then I’m ready to install the caps into the box.
Now I can still remove one side of the box. The other side I have begun locking down the wedges. I plane the top to a smooth finish.
And we’re all set to move onto the next step.
I hope you have enjoyed this installment of my blog, thank you for visiting!