Maruta Bench – Build 3

One of the final details before assembling the bench was to mark and cut the holes for the pegs in the tenons. After trimming and fitting each joint, I used a hollow chisel from the mortiser, and with a light tap, marked the location of the mortise on the tenons.

From there I could used those reference marks to layout the peg holes on the tenons themselves. I offset the holes towards the tenon shoulder by about 0.5 mm to create a drawer bore effect when installing the pegs. For those who may not be familiar with this technique, essentially it means offsetting the peg hole in the tenon from the corresponding hole in the mortise, such that when the peg is driven in it pulls the tenon and shoulder tight. The important thing to remember is to offset the hole in the tenon towards the shoulder. If you cut the offset in the opposite direction you’ll end up pushing the joint apart as you assemble everything… don’t ask me how I know 😒

One thing I need to mention is the orientation of the pegs. It’s pretty common to see pegs oriented square to the parts which they are joining. Like this:

That’s how I laid out and cut pegged joinery prior to working with Somakosha, where I learned a new method. The technique that those guys use is a to orient the pegs at 45 degrees to the joint, as I’ve done here on this bench. In addition, their technique also requires a relief cut from the end of the tenon down the center to the peg. You can just barely make out the relief cuts on the tenons below.

A few years back, the guys at Somakosha participated in some tests designed to measure the strength of houses built using traditional joinery during earthquakes. One of the things they learned, was that changing the orientation of the peg to 45 degrees and making a relief cut, has a huge effect on the strength and durability of the joint. With a peg that is oriented square to the structure, when there is major stress placed on the joint, the weak point becomes the space between the peg and the end of the tenon. Given the direction of the woods grain, when the joint fails, it usually fails because that chunk of material between the peg and end of the tenon just splits out. At that point there is really nothing holding the tenon in place any more, and for the most part the whole thing could be pulled apart.

But if you orient the peg at 45 degrees and cut a relief cut, when stress is place on the joint, the peg acts like a wedge and combined with the relief cut causes the tenon to spread apart and further tighten itself in the mortise (almost like an automatic dovetail effect). Also the grain is much less likely to split at the corners of a sloped cut vs. a sharp 90 corner, minimizing the likelihood of the joint completely failing.

That all sounds great, but is it really necessary for a piece of furniture? Probably not. Under normal use it’s probably unlikely that a joint will break using a standard peg orientation. But I figure there’s no harm in applying this technique. It adds a lot of strength for essentially the same amount of work. And you never know, sometimes people can be extra rough with furniture, plopping down with full force on to the seat of the bench, or kids jumping around, etc.

So with the peg holes and relief cuts done in the tenons, that was pretty much it for the main work on this bench. I didn’t take pictures of how I made the diagonal braces that go between the leg stretchers and short seat stretchers, but those are really simple pieces, essentially just 20 mm Ø round stock that will be plugged into corresponding round mortises. (You can just barely see one of the braces at the bottom of the picture below, along with one of mortises where it will go in the leg stretcher directly above it.)

Below is a little bit of video showing the assembly of the bench. It’s not the most exciting video, but it does show how the various parts of the bench went together. The trickiest part of the assembly was bringing the legs, seat frame, and diagonal braces all together. Since the legs and braces are set at opposing angles, I had to work slowly, tapping a bit on the legs then a bit on the diagonal braces. The final step shown in the video is installation of the pegs. I clamped the parts together while driving in the pegs to help assist in keeping the joint tight.

And here is the completed bench structure, with all the pegs pounded in. It really is nice to build a piece of furniture without glue, and not have to deal with the panic that ensues the second you apply glue. Glue-ups are always a race against the clock to assemble the joints before the glue sets up, while also dealing with cleaning up any drips and squeeze out. Not to mention handling all the clamps which require care not to damage the wood from excessive pressure as well as some kind of tricky arrangement to clamp angled parts like the legs of this bench.

Here you can see a bit more of the connection between the short seat stretchers, leg stretchers and diagonal braces. I didn’t use any special joinery for the diagonal braces, they are simply inserted into holes/mortises that are about 12 mm (1/2″ deep). The braces are essentially sandwiched between the leg assemblies and seat frame and bottom out in the mortises so they should provide pretty solid support for the angled legs when a couple of people plop down on the bench.

At this point the main tasks that were remaining were to trim and chamfer the pegs, apply a finish to the bench and weave the seat.

Trimming the pegs was pretty straightforward. I left each peg about 1 mm proud of the surface, and lightly chamfered the edges with a chisel. For finish I used a soap finish. I talked about using the soap finish on another ash piece of furniture the Toshi-Nuki Shelves. I really like the look of ash, but it doesn’t pair well with oil finishes in my opinion (it turns very yellow). Soap finish has an incredibly minimal effect on the color of ash, is easy to apply, cheap, and easy on the body.

After applying a coat of soap finish I moved on to weaving the seat. Weaving a Danish cord seat is really pretty straightforward. The initial stages can be a bit confusing, but once you get the hang of it, the process is really just a series of repeated steps. However the design of this bench created a couple of tricky areas that required some problem solving.

One area that posed a new challenge for me with this bench was how to weave the seat around the legs. The legs essentially break up the pattern since you can’t continuously weave down the length of the seat stretchers. Essentially the pattern gets broken up, creating a gap in the weave between the legs on both ends of the bench. Most woven seats that I have come across require the cord to be packed in tight within a given space, and if you don’t create a packed weave, individual strands tend to wander creating gaps in the finished seat. So on this bench, I had to figure out a way to secure the weave around the openings between the legs.

After doing some digging I found a couple examples of other benches with similar situations regarding openings within the weave. I saw a few examples where the problem was simply ignored, but at least one where the solution was to twist the weft strands such that the twisted portion essentially locks the warp strands, allowing you to start and stop the weave as you see fit. The following pictures will hopefully make the whole situation and solution more clear.

But one other issue that I also had to address was how to stop the paper cord from sliding around on the round stretchers. After doing a bit of head scratching my solution was to cut notches where I wanted the cord to start and stop. At first I envisioned having to carve out a wide trough for the cord to sit, but after doing a bit of testing I found that some pretty simple notches were more than enough to lock the cord in place and prevent it from sliding. The notches that you can see on the rail below were simple drawn vertically around the rail, corresponding to the intersections between the legs and short seat stretcher. I also figured that I really only needed to cut the notches on a portion of the rail, since once the cord wraps under and around the rail it will be secured by nails, so as long as the cord is solidly fixed between the notches and the nails it really shouldn’t move much. And after weaving the bench I feel like this turned out to be a pretty solid approach, as the cord is really well locked in place.

So finally on to the actual weaving. Here are the weft strands. You can see where I used a couple strips of wood to simulate the starting and stopping points of the weave on either side of the leg. You can also see the twist in the weft strands that will prevent the finished weave from shifting and sliding.

Here’s the first part of the pattern. If you look closely you can see the warp strands that run on either side of the opening between the legs. Those strands are woven between the long weft strands, exactly where the pieces of wood were in the above photos, effectively locking the pattern in place at those points.

Here’s a look at the end of the bench. The cord on this end had to wrap around the intersection of the diagonal brace which created a small gap towards the bottom side. It’s not a huge problem, but I do wish there was a more seamless way to wrap the cord around that area. I haven’t come up with any solutions yet. Something to think about for next time though.

Since the ends of the bench were somewhat tricky to weave, I decided to stop the pattern on the left side of the bench, and weave the other end while there was plenty of room. The tricky part with weaving a seat like this is always towards the end of the pattern as little by little the whole seat starts to tighten up, and your actual working space gets narrower and narrower. So I figured it would be easier to deal with the tricky weaving while the there was still plenty of room to work.

From there I worked back to where I had left off in the beginning. And here I only have a few wraps left to finish up the seat. I used to weave bench seats of the same size like this back in NY for another furniture maker, and those would take me about 4 hrs per seat to weave. This one took me about 6 hrs. The tricky areas around the openings between the legs were one slow down, but the other was just re-remembering how to do this since it had been many years since my last Danish cord seat. But in any case, a woven seat like this really doesn’t take that long, and the finished look is really amazing. And comfortable!

So with that the Maruta Bench was finished. Here are a few final shots of the finished bench.

Thanks so much for following along on this build. I’m not sure what the next furniture project will be, but I have plenty of ideas for some upcoming posts here on the blog, so stay tuned.