OK…you are probably getting sick of the kanna posts. Sorry, but you will have to bare with me a little while longer.
Emboldened by my mediocre success with my first dai making experiment, I decided to tackle making a dai to replace the one for my block plane. Over the years my lack of understanding and experimentation have made a mess of the original dai block. The blade is a small 36mm(1-1/2″) in width and the resulting plane(kanna) is light and very handy to have at the ready. I’ve missed having this kanna at my disposal.
Smaller should be easier right? Turns out, no, no it is not! Making a dai is exacting work, but making a small dai is a whole other level of fussy. This size is the limit for the tools that I have. My keyhole saw was the only saw small enough to cut the ramp slots. My 3mm chisel was a snug fit in cleaning up those slots as well. In the end though I was able to knock out a reasonably functional dai and now I have a functioning block plane once again!
One other project for this weekend was to build a plane sole ruler. Up to this point I have just been using the edge of my square. It works, but is not ideal. At any rate, a kanna does not have flat sole, well most of them don’t at least. I’ll not go into the different configurations at this point. The important bit is that certain sections of the sole are scraped lower (conditioning) leaving small contact points remaining. To check the conditioning you need an accurate straightedge. You can purchase a metal one specifically made for the task, but I couldn’t bring myself to shell out $90US. In Odate’s book he illustrates a shop-made solution. Basically winding sticks that are registered together thru the use of a couple of dowel pins. I’ve seen a few much fancier examples on the Internet, but I like simple. The idea is to take a single board and split it to create a book matched pair. The theory is that by book matching and then registering them together any movement in one piece of wood will be counteracted by the opposing piece. The top edges are beveled on each piece to create a finer contact edge. The two are then locked together and planed as a unit. Then the beveled edges are offered to each other. Any deviation from straight will be magnified by a factor of two. You then make corrections as needed until the two edges mate perfectly. Then, and only then, do you have a true straightedge. Then the plane sole ruler is used to verify that the contact points are coplanar and that the scraped areas are at the proper depth. Have a look at this video to see the plane sole ruler and the the process in action.
Ideally you need dry, stable wood for making the plane sole ruler. So up into the magic attic I went and descended a few minutes later with a 3″ wide piece of straight-grained pine. I then dressed and divided the board. Drilled for dowel pins, they are glued into one piece and friction fit into the other. Then I beveled the top edges and began the truing process. Simple and cheap.
A look at the profile.
The two halves.
I then used the newly minted plane sole ruler to condition the sole of my newly minted block plane. How’s that for self sufficiency? Like with my previous plane, I bedded the blade of the block plane at 45deg. Works great for planing the scraps of 2×4 and SYP that I’ve been running tests on.
I still have a whole lot to learn about the Japanese plane, but I’m at least up and running…finally!