This week I finished dimensioning, squaring, flattening and smoothing all of the parts to the walnut boarded bookcase, and at the end of one evening I stacked the sides, shelves and stretchers all together before calling it a night. I was struck with the thought that it didn’t look like much of a pile of wood sitting there for all the work that has gone into it. I’ve lost track of how many trash cans full of walnut shavings and off-cuts I’ve burned so far with this project, but at that point at least I was ready to begin joinery.
I’ve started cutting and clearing the dadoes for the shelves and following the instructions in ‘The Anarchist’s Design Book’ has proven very successful. Chris suggests clamping a batten and using another block of wood to create a guide. The idea is that this will ensure a kerf that is both square and plumb. I haven’t cut a ton of carcase dadoes by hand, but when I have I have usually just cut them free-hand to a knifed line. Most of those dadoes are inside joints and very few will ever see the light of day, but with this project I wanted to ensure that all of the exposed joinery would be nice and clean, so I gave the clamped batten method a try. It’s not exactly foolproof, and there is a learning curve, but once you’ve got it, it really works well.
The first key to making the most of this method is to be sure to clamp the batten dead square to the carcase and just on the outside of your line. You want the kerf to be “inside” the dado or else you’ll end up with a dado that is as wide as your shelf, plus two saw kerf widths.
I used another block (not pictured) to ensure my initial cut was square to the batten. After a establishing the cut I found it easier to remove the block and to simply follow my kerf to keep square as I cut down to define the 1/4″ deep dado walls.
A nice sharp chisel made quick work of bringing the dadoes down to depth. I made sure to define the ends of the dado first by placing my 3/4″ chisel right on the marking gauge depth line and giving it one sharp whack with the mallet. It’s also good to work “in” from both ends a little before clearing out the middle to avoid any blowout.
With the dado almost at depth I took several light passes with my freshly sharpened router plane to get a level, finished surface.
When I first used a router plane I couldn’t understand why surfaces like this eluded me. I wanted nice clean dadoes and It seemed like I was always ripping out chunks of wood, leaving what I would classify as a barely acceptable result. I mean, it worked but it wasn’t pretty. What I’ve learned over the past year is this:
- First, your router plane has to be sharp. Really sharp. The sharper the better. This isn’t always easy to achieve but it’s always worth taking the extra time. The Veritas router plane has a leg up here in my opinion because you can remove the cutter tip and sharpen it on a jig just as you would any chisel or plane blade avoiding all of the weird contortions you have to go through to sharpen a 90 degree cutter.
- Second, take light passes. Once you have your depth stop set, back the cutter off to take the lightest imaginable pass and then progressively work to depth taking no more than the plane can easily clear. If you have to push hard, you’re probably cutting too deep.
- Third, given what I just said, it pays to take out as much as you can with the chisel. It’s easier to sharpen a chisel anyway, and honestly you should be able to get it so that the router only has to take 3-4 passes at the most.
So that’s it. Saw, chisel and router plane. You gain a great deal of control cutting dadoes by hand, and it’s really not that time consuming. Once you get the hang of putting your batten where it belongs, you can easily have a finished dado in less than 15 minutes making a project like this seem much more manageable. Really, after preparing all the stock, cutting these is the easy part.