Rigorous Mortise? Nah, it’s easy…

I mentioned earlier this week that the pegged mortise and tenon is my favorite woodworking joint to make. One of the things that makes it my favorite is a feeling of competency and efficiency, and those are feelings that only come with practice. It makes a big difference when you begin a process with the expectation, rather than the hope, that everything will come together right.

I’ve been cutting mortises by hand since 2007, but it wasn’t until I built a commissioned Arts-and-Crafts office desk in 2013 that I truly felt comfortable with the process. That piece had over 100 individual mortise and tenon joints, more than half of them were through-mortises. Lots of practice, and plenty of time to refine my technique.

There are certainly no shortage of methods to try.

Christian Becksvoort pre-drills the mortises with a doweling jig and cleans it up with a sash mortise chisel. I’ve not found that pre-drilling the holes saves any time – unless you have really wonky grain, in which case the chisel will tend to want to follow the grain if you don’t pre-drill. Best to use straight-grained stock instead.

Chris Schwarz no longer uses this method, but he once wrote about a method of drilling a hole in one end of the mortise and then chiseling back from that hole until you reach the opposite end (the “Maynard technique”).

Peter Follansbee uses a traditional mortise chisel and starts by cutting a vee in the middle of the mortise, then working his way back to the ends. I really want to like this method, and I’ve tried it several times, but I find that my accuracy is compromised by switching the bevel back and forth like he does. I like to get my chisel in the right position and keep it there.

Which is why my preferred method is something along the lines of what Paul Sellers does. Actually, “along the lines” is dead wrong; I chop my mortises exactly like Paul Sellers does. Oddly enough, I had never even seen him chop a mortise under I was gathering links about different methods for this very post. Our only difference of opinions: he prefers a standard bevel-edge, chisel, while I prefer the traditional mortise chisel.

So, on that note, a change of plans. I had taken a bunch of pictures that were intended to demonstrate the method I use, but instead I’ll just post Paul’s video instead. If a picture’s worth 1000 words, a video must be worth 10,000.

 

Okay, I can’t resist a bit of commentary on Paul Seller’s methods. In all of his videos where he’s mortising something, he’s holding the piece in his face vise. That sure seems like a good way to add unnecessary stress to your vise and the screws that are holding it in place. I mortise with my workpiece clamped to the benchtop, directly over a leg, using a holdfast or a big handscrew. Like so:

Also, I mark out only three sides of the mortise: the top, the bottom, and the edge that is closest to the face. The chisel itself defines the fourth side, so I don’t find it helpful to mark out the far edge. The only thing to watch out for with this method? Don’t chop your mortise on the wrong side of the line! Sometimes, when the mortise is close to the face (like in this example), it’s obvious which side to chop on. Other times, when the mortise is more centrally located, it’s not quite as clear. I have chopped on the wrong side of the line before, so I tend to draw a little squiggle on the side where I need to chop. (I don’t usually darken the scribe lines with a pencil, though- that was just for the picture.)

My tavern table had 10 regular mortises and four double mortises. The last four that I chopped measured 2″ long and 1-3/4″ deep. Out of curiosity, I timed myself and found that I chopped them in 4-5 minutes each. It’s quick and painless once you’re familiar with the process, and there’s nothing quite like sliding a joint together for the first time and having it look like this: