Joints For No Reason - Koshikake Aritsugi
To brush up on general joinery skills, I'm going to be practicing at least one traditional Japanese joint each week. This week was the Koshikake aritsugi - stepped dovetail splice. This joint doesn't really have a place in furniture making, but is a good skill builder and a lot of fun
The completed joint
I start with a 5/4 piece of poplar and get it square.
Next I cross cut it in half and clean both ends on a shooting board
Tricky layout.There are a lot of cuts to make here. My goal was to make each one in an order that wouldn't remove any of my reference lines for the other cuts.
I cut the dovetail first with my Dozuki
Next I flip it in the vise to saw for the shoulder
The step actually goes below the dovetail so I rip to the second scribe line
Now to cut the cheek. I make a channel for the saw to ride in against the knife line
Then saw the waste off
Now I need to clean up the faces with a wide chisel
Once complete I cut out the waste from the tail
In order to layout the socket on the adjacent piece, I first need to cut the step. I rip it staying inside the line, then crosscut the waste off like shown above
Now I transfer the dovetail
No good way to sneak a saw in here, so this is 100% carved using a 12mm and 44mm chisel
Once done I clean up the inside corners with skew chisels, and make sure everything is square
And it fits.