Posted by Hello and welcome to my blog! This post completes a series in which I’ve built a Tea House garden bench of Honduran mahogany. This bench will be used outdoors and preparations have been made to help this bench endure the elements. I’ve detailed the steps taken to ensure that it will last in addition to having detailed the remaining steps of cutting and fitting the dovetails and stretcher to post connections.
The previous post ended with the center upright having been seated in place. With that now completed, I could install the stretcher. The stretcher is an important fixing point for the remaining joinery.
Once the stretcher was in place and squared up, I could then begin to layout the remaining joints. I transferred my baseline marks to the stretcher using a try square, then used those marks to scribe the tenon shoulders the full way around the stretcher. Next I applied marks to size the tenons and finally made cuts to form the tenons.
The tenons will form a type of notched connection known as a cogged joint. A cogged joint is one in which a notch is formed in the tenon, the notch hooks over the edge of the adjoining upright and a wedge or pair of wedges are put in place to keep the joint seated.
Having space for a wedge offers an advantage that the joint can be seated around a stationary tenon, or vice-versa. Layout marks were made and the tenon transferred to the upright. I’m careful in setting my gauges at this point so that my baseline for the tenons lines up along the entire bench.
I cut away the mortises, keeping away from the lines initially then paring to them with a large tsuki-nomi.
Once the tenon can be fitted through I use a knife to mark out for a notch which will be cut into the tenon.
The notch is then cut and the tenon reinstalled and test seated. My preference is for the notch to compress the adjoining wood and so I cut these joints for a tight fit and seat them carefully.
The shoulder is very carefully fitted to ensure that it seats squarely. Most often when building with handtools one prides themselves on cutting the shoulders and sides of a tenon ‘off the saw’. That is hardly the case here at such a critical connection, the shoulders are cut accurately but then finely tuned until the adjoining sides seat cleanly and squarely. This is done prior to marking out and cutting the notch.
Next, to fit the uprights into the bench. The uprights feature the dovetailed corners and they are cut exceptionally tight. The tight dovetails along with the need to jog the stretcher into place while assembling the end joints made for quite a a bit of apprehension. I used what slack I had available to me to seat everything into position then carefully drove the dovetails into place while wiggling the stretcher closer and closer to a seated position. This was done after applying glue to the joint and it made for a real ‘hair-raiser’, especially given that I did not test fit the dovetails out of fear of damaging the large joint. Wooden joinery compresses each time it is test fitted and what starts as tight can be quite loose after a few fits. I want the joinery tight so that the bench can stand on its own without reliance upon glue. The glue is acting more as a sealant than anything else.
As the joint seated, a sigh of relief escaped and then I moved on to the opposite side to repeat the process.
Once the joints were both seated my apprehension was lifted.
With the joinery now in position I could take a moment to look upon the changes I’ve made in this design. I’m happy with the heft of this iteration.
Dovetails are a fairly simple joint, but as the thickness of materials increase the joint becomes increasingly difficult to cut cleanly. On half blind dovetails I can taper them slightly so that the joint tightens up slightly as it is fitted, however with through dovetails no such tapering can be done, relying instead on cutting squarely and hitting my knife marks exactly. There are very few exposed through dovetails in traditional furniture, and I assume it is for that reason. Often enough through dovetail joints would be covered by molding or otherwise hidden.
Next I detailed the exposed material created by setting back the pins. The angle of the tails was reversed and applied to the outside which was then detailed with a chamfer around all edges.
The final touch was to create a facet from the edge of the pin to the end of the tail. This was done with a paring chisel and it nearly completed the woodwork on this bench.
The last and final step of the woodwork was to create two wedges for each of the through tenons and seat those, securing the cogged joint connections.
Next I headed out to the machine shop and turned out some brass feet on the Bridgeport machine. These are 360 architectural brass, otherwise known as free-machine brass, the only brass I plan to use moving forward, having learned the lessons of the recent past. I still tremor at the thought of machining naval brass.
If my readers will recall, I applied long grain patches into the end of each upright. Those were not only to correct the split at one end, but also to allow a side grain exposure which would be used to hold the screws for each of the applied feet. Pilot holes were first drilled followed by a thread cutting screw and finally a brass screw to seat the feet.
The thumb screw adjusters will allow for the bench to be leveled out on uneven terrain and allow for the bench to be lifted from the ground enough that these uprights will not soak up normal rainwater. As an additional precaution I applied a sealer to the end grain.
The bench is now complete! I very much look forward to your comments and questions. I’ve setup a photo studio in my shop in hopes of improving my photography, please have a look through.
Wow, Brian, beautiful simplicity and cleanness!
Question: Would a sage-kama joint be a good option for joining the stretcher to the outside uprights?
Thanks.
Rob
Thank you Rob! I think you are referring to shitage Kama, Chris Hall wrote up a very detailed series on stretcher to post connections and in my interpretation of it understood that the shitage Kama was more suitable to blind connections because the dual abutments of the cog joint were more secure. Excellent question, thank you!
Brian,
I was thinking of a variant of a through wedged M&T, something like this:
http://www.davidfay.com/full.php?image=95.fall.hf.detail.jpg&title=NarraBedWithExposedJoinery.gif
Wondering how it would hold up over the seasons.
Rob
Hi Rob, I’ve cut those for an indoor coffee table but not for outdoor furniture. I’m sure they would hold up quite well.
Nice Job Your work is exceptional
I hope there’s a flaw in there somewhere so I don’t feel like such a hack
Iv’e been following your blog for several years and appreciate the hard work
Haha! Thank you Charles!
Beautifully executed in form, style and craftsmanship! Details are definitely making the design in this amazing piece! Inspiring work!!
Thanks David! Very much appreciated!
wow beautiful, outstanding work Brian and great pictures too.
Thanks Salko! Much appreciated!
The work – and the photographs – are indeed beautiful. David Pye’s ‘Workmanship of risk’ in practice. But please could you reduce the size of the photographs before you upload them? In our area, internet speeds are less than stellar, and the frustration of waiting for these beautiful images to upload is almost unbearable! Many thanks for posting…
Thanks Alan! I appreciate the comment, I do feel similarly to David Pye and try to work with some of his notions in mind. WRT the photos, are you referring to the gallery images? It’s much more common for me to recieve the opposite as a complaint with the other images.
Not sure if this is the right place for this discussion… Down loading photos takes too long because of the large file size… It takes longer to upload as well…
I’ll keep it in mind for future posts.
Very neat. I particularly like the detailing of the dovetails. A nice way to reduce the sharpness of the angle.
Iain
Thank you Iain!
Wonderful. As always.
Thank you kindly!
Saw the finished bench on Instagram before reading your posts here (I like to save them up and read the project at once). I had mistaken your cog joints for tusk tenons and I was trying to figure out from IG photo how you seated it so flush across the top (assumed some sort of ‘T’ pin but the flush seating had me puzzled). Always rewarded with something new in each of your blog posts. Thanks for continuing to share the details of your high caliber projects!
Thank you! Glad to have such a positive reception and of course I’m always glad to hear it when my projects provoke real thought on their engineering.
Very well done. Congrats Brian.
Thank you!