Workbench Joinery: 10 Years of Tenons
Tomorrow morning I start a new workbench class at the Marc Adams School of Woodworking. While I’ve lost count of the number of workbenches I’ve built or midwifed into this world, I never tire of the grueling and exhilarating labor they require.
For each class, I design a new workbench from scratch that is suited to the material I have gathered for the class, the needs of the students and the workbench hardware they want to use. The design process takes an entire day because I actually have to design 15 workbenches with the fewest machinery setups and part sizes.
That might seem like drudgery, but I take sick personal pleasure from the process.
This week we are using bench bundles from Horizon Wood Products. So I’ve designed our benches around the 12/4 and 8/4 ash included in these affordable bundles. The guys at Horizon are an absolute joy to deal with and they take immense pride in exceeding your expectations. For example: Out of 15 benches, I think we have only two knots in this entire pile of wood.
Because of the 12/4 material, I decided that the benches should have a single through-tenon on each leg that penetrates the top. I’ve built many benches using this type of joint and I have found no difference between it and using the sliding dovetail/tenon combination shown in Roubo (other than the aesthetic difference).
By using a single tenon and mortise, we can create the mortise while gluing up the tops and save almost two days of effort by skipping the dovetail. You might not believe my estimate, but I do.
The tenon will be drawbored and wedged into the top. It won’t really need stretchers below for the finished bench to stay stout, but we will have them anyway – everyone deserves a shelf below their benchtop.
The stretchers below the top are made using 8/4 ash that is tenoned into the legs – each tenon is 7/8” thick, 2-1/2” long and designed to be cut with only one machine setup. The base will be drawbored together using 5/8”-diameter pegs. After many years of mucking around with different sizes and species of pegs, I’ve found that a 5/8”-diameter store-bought dowel does the trick every single time. Even with a 1/8” drawbore offset.
One last thing I’m looking forward to with this class: Working with the students. Unlike every other class I teach, workbench classes are all about teamwork. You can’t build a bench like this in 40 hours without some serious help. Workbench classes forge personal bonds that last years and years.
I’ll be posting videos all week here on our bench project. So stay tuned.
— Christopher Schwarz