Joints are selected for many reasons. Strength is certainly high on the list, but it’s not the only factor. Aesthetics play a large role in joint selection and can add that extra focal point a piece may benefit from.
I’m not suggesting joint strength should ever be seriously compromised for looks. The amount of strength a joint provides can’t be faked and always has to be ample for the specific situation you’re dealing with. Adding a decorative element to a joint is just that: an addition to an otherwise strong enough joint. And notice I said “strong enough.” Some joints are tasked with keeping a large, heavy piece of furniture together, while others just need to provide enough strength to keep two pieces of wood together under minimal stress. Though there are many examples, the first one that comes to mind is a picture frame. All situations call for a different level of strength, and once that level is met the basic necessity of a joint is met. It’s at that point you can consider embellishing a joint. In my instance, I made a walnut mirror frame for a small bathroom, so lots of strength wasn’t needed.
And sometimes a strong joint just doesn’t look as nice as a weaker one. A half-lap joint can be incredibly strong, though it’s not always eye-catching, and adding a faux tenon might enhance the overall look of the piece.
Strong woodworking joints were more necessary in the past, as adhesives weren’t overly strong and durable. These joints are what draw the eye today, but with the advanced adhesives we have at our disposal we often don’t need to spend the time or energy to machine joints like they did back then. That’s not to say a good adhesive will fix a weak joint, but a good adhesive can allow you to use different joints in many instances. But if you still want a more traditional look, adding faux tenons might be your answer.
Keep Them Aligned
When cutting the strips to width the centre one should be cut so the contrasting wood strips will look good when the tenons are installed. This means the width should be approximately equal to the width of the flat portion of the mortise. If you look closely at the end grain, you’ll notice Brown ripped the pieces from the board and kept them in order so the grain would align and the colour would be even across the tenon.
Trim to Width
Not only does the faux tenon material need to be cut to the correct width, but it also has to have equal amounts of material on the left and right ends of the tenon if you’re using contrasting strips of material to make the tenons.
Round Their Edges
Since Brown decided to use a round tenon on this project, he used a router bit with a radius that was as close as possible to half the dimension of the thickness of the tenon. It likely won’t be exact so some hand sanding might be needed to fair the rounded edges and create a gap-free fit.
Insert and Mark
With the tenon length fitting in the mortises, Brown inserts one end, then adds a light pencil mark where the face of the workpiece meets the tenon. Further trimming and shaping of the faux tenon will reference off this pencil mark.
Working towards the pencil line, Brown first rounds the wider faces of the tenon on a belt sander. This process should be completed slowly, as it’s very easy to remove too much material quickly and ruin the overall pillowed effect.
Once an even radius is machined into the two wider edges Brown lightly pillows the ends of the faux tenons. Once the ends are pillowed the final shaping involves fairing the four transitions between the wider faces and the ends of each faux tenon. This step is best done with some coarse grit sandpaper and a hand sanding block, as a belt sander would remove material too quickly.
A Bit of Glue
With the face of the workpiece sanded smooth, and the faux tenons evenly pillowed, some glue added to the inner face of the mortise is all that’s needed to keep the faux tenon in place. Any glue added to the tenon will almost certainly squeeze out, causing problems once a finish is applied.
Is a faux tenon strictly for looks?
That might be a trick question. By definition, a faux tenon is strictly for the purpose of adding a decorative feature, as the word “faux” implies. On the other hand, a very similar approach to machining can be taken to create a deeper mortise and add a longer slip tenon to a joint, which increases both mechanical strength and face grain glue surface area. The bottom line: each situation is different. The faux tenons I made for this article are strictly for looks, but if the mortises are machined deeper, and the tenons are cut longer, they can overlap both workpieces that make up each mitre joint and strength can be added to the joint.
This general approach could also be used to conceal a simpler fastener like common wood screws. By sinking the screws well below the surface of the workpiece, then machining the mortise directly over top of the screws, the faux tenon would hide the screws and provide a point of interest. You’d obviously have to be sure not to machine into the screwheads while machining the mortise.
Start with the mortise
There are three main ways to create the mortise in the piece. Which one you choose depends on the tooling you have and how comfortable you are with each approach. The mortise is generally created first, as it’s almost always easier to machine the tenons to fit the mortises than the other way around.
Using a plunge router is a good option, mainly because the dimensions of the mortise can be easily customized. Bits of all various diameters are available, so the faux tenon can be just about whatever thickness you want and any length of mortise can be routed, too. When plunge routing the mortises just be sure to support the base of the router properly so it doesn’t tilt while in use. Clamping a length of material to either face of a workpiece, flush with the face you’re routing, is an easy way to increase support for your router. And if the mortise needs to be machined on the face of a workpiece, a simple straightedge clamped to the workpiece, with a piece of wood clamped to the workpiece at either end to act as a stop, will guide the router while making the mortise.
Hand tools can also be used to create a mortise for the faux tenon to fit into. Sharp chisels, quality layout and marking tools, followed by accurate hand work, can leave you with a good mortise to insert the faux tenon into. Some also use a drill to remove much of the waste in the centre of the mortise.
The final method, and the one I find fastest and easiest, is using a Festool Domino to machine the mortise. It’s very quick and easy, though there is the obvious added expense if you don’t already have a Festool Domino. Another downfall is the fact that this method isn’t as flexible when it comes to sizing both the thickness and width of the tenon. My Domino XL machines a mortise about 1″ wide, and came with bits that are 12mm and 14mm in diameter. The standard Domino has narrower bits.
With the router and Domino approach, the resulting mortise will naturally have rounded ends. They could be squared up if you want tenons with square edges.
Contrasting faux tenons
As always, what to do in this situation is up to the maker. I generally prefer including at least a bit of contrast when I make faux tenons, though every situation is different. I often use the same species to make the majority of the faux tenons from, but add a few layers of contrasting veneer to the tenons. I determine the size of the tenon, and then laminate a few strips of solid wood, separated by contrasting veneer, for the tenon material, spacing the contrasting pieces of veneer in an aesthetically pleasing way. I also leave the tenons in one long blank for now, as it’s easier and safer to machine.
When laminating contrasting species keep in mind you will see only the end grain of the tenon once it’s assembled. For this reason, I always rip strips of wood from one blank and reassemble them in the same orientation so the end grain has the same colour and grain pattern.
With the mortise complete, machine the tenon blank on a round-edged tenon to width so it’s ever so slightly wider than the mortise. No more than 1/64″ wider is what I aim for. A square-edged tenon can be ripped to width so it’s the same width as the mortise. Next, dress the blank to thickness so it fits in the mortise. A friction fit is what you’re after, as any thinner means a small gap will be visible around the perimeter of the faux tenon after it’s installed.
I prefer a rounded tenon, though the choice is yours. I chuck in a router bit with the same radius as the mortise and carefully set it up in my router table so I can round over the four edges of the tenon stock. Some test passes are helpful in setting up the height of the bit and location of the fence to round the edges over so they fit the round mortises nicely. I leave the width of the faux tenons slightly wider than the mortises because it’s hard to machine the rounded edges perfectly, so I have to hand sand the tenons to fit more accurately. And there are many times when I don’t even have a round over router bit the same diameter as the bit I used to machine the mortise, so the mortises have to fine-tuned by hand to fit properly.
A fit that’s slightly too snug is preferable at this stage, as the tenon can always be sanded or machined to fit better. Sometimes a few passes with a medium grit sanding block is enough to remove enough material for a good fit.
Cut them to length
Working with a long length of tenon material, I insert one end into a mortise as far as it will go and mark a light pencil line around the tenon where the parts meet. This line will help guide me when pillowing the visible end of the tenon. If the mortises aren’t all exactly the same depth, mark the tenons so they can fit back into the correct mortise. Now is also the time I make sure the tenons fit into the mortises properly. A bit of hand sanding at this stage might be needed.
Thicker tenons can protrude further from the mating surface, though once again there are no hard and fast rules here. The tenons pictured in many of these images are 12mm thick and protrude 1/4″ from the mortise.
There’s nothing wrong with creating flush tenons, rather than pillowing their ends. It’s a lot easier and faster. It all depends on the look you’re going for.
I marked a line 1/4″ beyond the pencil line and cut the tenon to length. Using a belt sander tilted on its edge, I evenly rounded the ends of the tenon, being sure to leave the pencil line completely intact. Next, I used a hand sanding block to smooth the tenon ends and create a pillowed end that looks and feels evenly rounded. At this stage you can erase the pencil mark around the tenon, where the tenon meets the mating piece, then lightly sand that area to ensure the lines are gone. Finally, sand the rounded end of the tenon smooth, as once it’s glued in place you’ll apply a finish.
At this point don’t insert the tenon fully, as it should be snug enough that you won’t be able to get it out.
At first, it’s tricky to evenly round the ends of the tenons with a belt sander or other machine, so you might be smart to test your skills with a practice faux tenon. Create a mortise in some scrap, drill a hole from the base of the mortise to the other side of the scrap so you can stick a screwdriver or something through it to push the practice faux tenon out, then get to work. Sand a bit then check for fit and repeat. Your first one might be awful, though you will improve with practice.
Glue them in
Before you glue in the tenons, don’t forget to sand the area around where the tenon will protrude, as it will get in the way of you sanding that surface later.
The end grain of the tenon naturally soaks up a bit more of any finish you apply to the project, and will need a few extra coats. You can choose to apply a few coats of finish to the pillowed ends of the tenons before installing them, or just apply a bit of extra finish to the protruding tenons while you finish the project.
Apply glue to the inner surface of the mortise, coating it just about to the outer, visible surface. You don’t want too much glue in the mortise because it will squeeze out once you tap the tenon into place, making a mess. Really, you shouldn’t need much glue to keep the tenon in place. I always leave the edges of the tenon free from glue, as it will surely squeeze out while the tenon is being inserted. Gently tap each faux tenon home and let it dry before applying a finish on the project.
Small, fancy details like these are one of woodworking’s greatest pleasures, so be sure to pat yourself on the back for a job well done.
A Different Approach
There are many slight variations on this general approach. I’ve used Baltic birch plywood as tenon material in the past. I was happy to discover a piece of 1/2″ thick Baltic birch plywood is the same thickness as my 12mm Domino cutter. I just needed to rip the material to width, round the edges, fit the tenon with some hand sanding and cut it to length.
One very simple option is to drill a hole with a sharp drill bit (I prefer a brad point bit for this task) and glue in a length of contrasting solid wood dowel. You can even pillow the end of the dowel by chucking the piece of dowel into a drill, pulling the trigger and shaping it with some sandpaper.