branagan custom

Recently I finished building a coffee table, the frame of which is built with mortise and tenon joints. In this design there are fourteen joints which is the most of a single joint I’ve had to cut in a single project (not counting every dovetail as singular) and if there is one gap or weakness in the internet content out there (that I’ve found so far) it’s the lack of guidance at scale with hand tools.

What I mean by that is most available instructional material shows the process and technique for cutting one joint in isolation. The instructor will show the process to chop a mortise, cut the tenon to fit the mortise and do so in great detail which is extremely useful for learning. But the next step is usually: “Now I finish the rest of the joints off camera and we move on to the next step”. I have yet to find material on how to batch the joints, cut a project’s-worth together efficiently, with advice and guidance on grouping tasks or processes. 

Note: this is from a hobbyist’s perspective learning from free material out there, and running a few quick searches online. There are a few examples I can think of where this topic is PROBABLY covered in detail but I have not paid for those projects / tutorials (yet). And again – hand tools only. Most all of machine-based woodworking is built around batch processes.

It’s really inefficient to complete joints individually one by one on a project that has more than a handful. For some, maybe efficiency isn’t a concern but in my limited time I want to improve the speed of my processes where I can to get the project done and move on to the next one.

This project was a perfect opportunity to experiment with batching, techniques and workholding to figure out what works best for me in my shop. I’m dead certain I’ll have plenty of projects involving plenty of mortise and tenons in the future so to me this is time well spent.

I started with mortising and experimented with a few things. I won’t go in to agonising detail on every process but I’ll try to point out the key learnings from each step. Let me emphasise this is not the be all and end all; this is not an “ultimate guide” to mortising or cutting tenons, just my experience on this project.

Batching mortises: I decided to do four at a time – two legs; the two end frames.

• It starts with layout and efficiently marking all mortises identically. This was an area I struggled with at first just figuring everything out (I’m not a Sketchup man). Once I decided on length, width and position of the mortises it was easy to set the mortise gauge and mark the sides of the mortises from the reference edge. The start and stop points were different. 
• For the mortise on the top of the legs I tried two ways – set a marking gauge from the top of the leg (squared up) and first mark the top of all the mortises then reset the gauge and mark the bottom, and the other was gang the legs up and square the lines across with a square and knife. For efficiency I preferred the gauge. For the mortise in the middle of the leg I had to gang the legs up and mark across the start and stop point.
• I used a half inch bevel edged chisel for all the chopping, a quarter inch chisel for clearing out the waste and a 1” chisel for paring the side walls.

Mortising techniques:

1. I started with chopping them from end to end Paul Sellers style. The mortises were just over a half inch wide and 1 ½ inches deep. With this process it generally took about 20 minutes per mortise. It’s a reliable way to chop and works well but can be a bit laborious at times. 
2. I also tried the traditional method starting from the centre, creating a divot and working out to the ends. I didn’t find any particular advantage over the end to end method but I only did this once. I would like to practice this more to find out if the efficiency improves over time.
3. Next I tried drilling out the bulk of the waste with a brace then chiseling out what’s left. This was by far the most efficient and least effort process. It was also easier to batch them by clamping the legs together, drilling all the holes, chop out the bulk of the waste, then refine them.

Workholding:

1. I tried two main workholding techniques. First I held them by sitting on the workpiece on the bench. My bench is low enough to just sit on the edge holding the workpiece down – think riding sidesaddle. I tried this with the piece to my left and to my right (because of the light setup in my shop). I’m right-handed so having it to my left was much more comfortable, holding the chisel in my left hand and hammering with my right.
2. The other way I tried was with a holdfast, with the piece perpendicular to the vise across the bench over the legs. This did give a solid hold, a good view of the action and for comfort I sat on my stool. My only criticism is the friction when moving the workpiece, having to release the holdfast then secure it again. It’s a quick operation and I do love my holdfasts but not as quick as simply standing up off the side of the bench to view or move the work.

Batching tenons

• Again it starts with layout. How do we guarantee we mark the tenon to remove the right amount to thickness, to width, and all in line on either end? 
• For the thickness of the tenon – I tried first using the mortise gauge but on the first one this went awry – the mortise gauge I use has two pins, which also have a thickness. I kept the same setting and worked exactly to the lines but the tenon ended up too thin by the thickness of the gauge lines. 
• I switched to getting approximately how much material needed to be removed from either side marked directly off the mortise. Even though each mortise should in theory be identical, there are always slight variations so the tenon needs to be fit to its particular mortise. 
• I referenced the tenon end to the mortise and marked off it directly, also checking by measuring the width of the mortise and making sure the tenon was the correct width in the centre of the piece. Instead of resetting the mortise gauge every time I used the wheel marking gauge from either side of the tenon piece to mark the opposite face of the tenon to make sure it was dead centred. 
• I used two carcass saws – a crosscut and ripcut – for all the sawing on tenons, a Stanley router plane for paring the tenon cheeks, and chisels for cleaning up the shoulders.

Tenon cutting techniques

1. I experimented less with cutting the tenons and only sawed them. Since tenons have to be fit to the mortise each one does take individual effort so it’s more difficult to batch them together. I cut the tenons on one workpiece (either end) then fitted them, but this was quick work. 
2. I marked the shoulders with a knife, chiseled a knife wall to define the shoulder, sawed the shoulders and cheeks then used the router to slowly pare the tenon cheeks until it fit snugly in the mortise. Next I pared back the shoulders neatly to the knife line, marked the width of the tenon and sawed in the same sequence. If the tenon was too wide I pared back with a chisel, and cleaned up the shoulders to the knife line.

Workholding

1. Simple – in the vise.

The tenons were an individual process, at least for me in this project. Next time I may experiment more with the tenon cutting process to make it faster but for now, beyond cutting precisely to my line and having it fit off the saw – which I know is not something I’m skilled enough to do yet with one tenon never mind fourteen – I’m ok with the individual process since it goes fast anyway. I’ve seen some material about mortising guides and tenon cutting guides which would absolutely increase efficiency and repeatability, it’s just something I haven’t played with yet.

I’m happy with the takeaways from this process. My preference from these tests is

1. Drill out the bulk of the waste with a brace (clamping a few pieces together side by side then holding them down with a holdfast) on a batch of mortises and then
2. Sit on the workpieces one at a time on the bench to chisel out the waste. It’s a solid hold that’s very accessible, no time at all to pick it up and check your work or flip it around. Once that process is done then
3. Sit on the stool with the workpiece loose on the bench for the final wall and end paring.

Next project I’ll really put this process to the test now that the experiment is over and see how it really fares in a batch. The experiment focus will be on improving the process and efficiency on the tenons (guide and jig-free for now).. Stay tuned.