Some readers seemed confused by my description of assembling a benchtop with the help of a “loose tenon.”
The expression doesn’t mean that the tenon rattles loose in the mortise. Rather it means that the tenon is not integral to either piece being joined. It is like a Domino or a biscuit. It enters mortises in both pieces.
I drew up two illustrations to show how this works. The drawing at the top illustrates the joint when it is apart. The loose tenon is shown floating between the two components of the benchtop.
The second illustration is an “X-ray” view of the assembled joint with 1/2”-diameter pegs piercing the benchtop pieces and the loose tenon.
“Loose tenons” have many other names, including “slip tenons” or “floating tenons.” All these terms are accepted in woodworking journalism.
We think of loose tenons as a modern joint, but it is far from it. Early Greek and Roman boats were made with loose tenons that were pegged to keep the hulls together.
I’ve always been fascinated by the fact that Richard Maguire also used this same technology to glue up his benchtops (read all about that here). I’ll be honest, I’ve always relied on glue alone (when I didn’t have a monumental one-piece slab top).
But my view changed a couple years ago when we got a bad batch of epoxy and several benchtops delaminated. If I ever have to glue up a slab benchtop again, I’m adding loose tenons.
Interestingly, Maguire doesn’t drawbore the loose tenons in his tops. He states: “a draw bored peg here would have been much weaker than this straight through approach.” I do believe I will be experimenting with this joint – both drawbored and not – to see for myself.=
Maguire wasn’t the first to come up with the idea of loose tenons in a benchtop (though I heard it from him first). Recently I got to inspect an early 20th-century French workbench from La Forge Royale that used the technology.
This commercial workbench was surprisingly rough in manufacture. Joints were deliberately overcut throughout to make the bench easy to assemble. The “breadboard” ends were merely nailed or screwed on. No tongue. I could go on and on. It’s still a great workbench (and still standing after 100 years), so I’m not knocking it. But I was surprised.
Despite the rough construction, the builders took the extra time to add loose tenons in the benchtop’s joint. That fact says a lot to me as to how important a detail they thought it was.
Some things in woodworking are hard-earned. Translation: I might not be so bright.
This week I performed some maintenance to my circa 1505 workbench designed by Martin Löffelholz. I’d built the bench last year using components that were soaking wet. This was not my preference, but sometimes we don’t have a choice when it comes to wood.
So what would be my preference? A wet top and bone-dry legs.
In my case, the tenons on the four wet legs had dried out faster than the wet benchtop. Because the ends of a stick of wood dry out before its middle, this was to be expected. As a result, three of the tenons became loose in their mortises, and I needed to re-glue and re-wedge them.
This is quick and easy work, maybe an hour. And because I use hide glue, there was no need to scrape off the dried PVA glue to remake the joints. (Yay for animal glue – for the 102nd billionth time.)
What’s the point here? Well, if you’ve ever made a workbench with through-tenons or through-dovetails then you know that the most difficult part of flattening the benchtop is dealing with the recalcitrant end grain. It can stop your handplane short, no matter how sharp it is or strong you think you are.
This week I got smart. Usually when you make a through-tenon, you make the tenon over-long and then saw or plane it flush to the surrounding wood. This is a good idea when making doors or small boxes. But when making workbenches, perhaps not.
This week I decided to cut the tenons 1/16” shy so they would end up recessed instead of proud when the joints were assembled. And, after assembly, I chiseled the wedges down flush with the tenon.
As a result, the benchtop was easy to flatten. My jack plane didn’t encounter any end grain until the last few strokes of flattening the benchtop.
Why haven’t I done this for the last 100 workbenches that I’ve built with my students, for customers or for me?
Lesson: Don’t be a Schwarz. Cut your workbench tenons short.
This post is by request. Several people have asked me to assemble all the links to the stories in this series in one posting so it would be easy to share or to find in the future.
Of all the workbench personalities, only The Undecider has driven me to reconsider my career in woodworking.
Like herpes, when you encounter The Undecider, everything seems kinda normal at first. But then, inexplicably, you cannot get rid of him.
The Undecider: Hey, I LOVE that Robo workbench on your blog. I was wondering if I could ask you a few questions about wood movement, wood selection and anything you would change if you built it again.
Me: Sure…. And blah, blah, blah.
Six weeks pass.
The Undecider: Hey, that Nickelback Bench is amazing! It really got me rethinking my workbench plans. Do you think oak would work for this bench? Could I equip it with a quick-release vise?
Me: Sure…. And blah, blah, blah.
Seven weeks pass.
The Undecider: Hey, I just read the article on John White’s “New-Fangled Workbench.” I was wondering if you could compare the strengths and weaknesses of this bench with the Rubiot bench, the Niklesen and this Newfangled one.
Me: I’ve never even seen one of these benches from John White. I read his article, of course, and it’s very interesting. But I’m afraid you know just as much as I do.
Eight weeks pass.
The Undecider: Hey, have you seen the height-adjustable bench? Do you think that could be combined with a Robo bench and the planing platform from the Newfangled Bench? Love to get your thoughts on how this might work.
I put the email aside. I needed to think of how to answer this email without using the phrase: “How many Hot Wheels can fit up your butt?” This process takes a couple weeks and includes some guided meditation. Finally, I am ready to answer this without sounding like a pirate. Then my email dings.
The Undecider: Hey, me again. I’ve actually been thinking I should just buy a workbench and “get to the good part” – you know, making furniture. But I can’t decide if the Lie-Nielsen bench is really worth the money compared to the Sjoberg. Do you think you could do a side-by-side comparison for me? Can’t wait to hear your thoughts!
Me: Dude, my thoughts would get me arrested in 22 states.