Saturday, July 31, 2010

Fox Wedged Tenon

Fox wedging is a joinery technique for a mortise and tenon joint where the wedge is fitted into a sawn kerf in the tenon. As the tenon is driven into the mortise, the wedge flares the split tenon and locks it in place.

High definition version of the video below can be found here.

One commenter asked if I had bored a flared hole to match the flared tenon. I did not. But you can cut a dovetail-shaped mortise, as shown in the illustration at right, which makes for a very strong joint. In the case of the drawer pull, I felt that the extra strength wasn't necessary.

The illustration is from this website.
The music is "Somewhere Over The Rainbow" by Israel Kamakawiwo'ole.


Darnell said...

Awesome, Kari.

Your honesty rules.

Eric said...

Very nice video, Kari! Thanks for sharing that with us. I was thinking about using this when gluing my big ol' wooden screw to the new head I made. But I was worried about the wedge being too long and whatnot. I suppose I didn't think you'd be able to get the wedge all the way in on the dry fit - looks like I was wrong!

Already did my screw head - so next time I'll give this a try!

Adrian Baird Ba Than said...

Very cool concept,annoying wee split though...
Good to see you're no longer swithering on what to do next!
So,what next?

Alan Garner said...

As usual for you, beautiful work. Question regarding drilling a hole: I recall one of the ww mags doing some testing on the theory (that drilling a hole will keep it from splitting) and found that the hole was not necessary. Have you heard, or read, such?

Jonathan said...

Did you flare the hole as well?

Kari Hultman said...

Thanks, Darnell. I'm not afraid to show my frequent boo-boos. haha

Eric, I actually did not dry-fit the joint. I just hoped that by checking the length of the wedge when it's seated in the tenon, and by making the wedge pretty thin, it would work out. That's the scary part about this joint--you only get one try. However, when you fit the wedge in the tenon, you can put it up to the mortise to see how much larger the diameter of the tenon is. Mine was only slightly larger, so I figured it would work.

Black, I jammed a bunch of dark paste wax into the split so no biggie. What's next? I'm still vascillating.

Alan, I haven't read anything about not drilling a hole, but I would never not drill a hole. Even if it's unnecessary, drilling a hole is easy and it adds an ounce of security.

Jonathan, I did not flare the hole. The joint is very strong. I held the drawer in the air by the knob right after I fitted it and it didn't budge. The drawer is very heavy, so I doubt the pull will come loose in use.

Anonymous said...

Hey Kari

Great video. Im wondering though, will this work for larger joints such as those used in table leg / furniture construction?

BTW, will you be my partner in the next whack-a-mole competition? We could kick some serious arse!!

Great stuff, I agree with Darnell I love your honesty.

Dave B

Larry Marshall said...

Great tutorial, Kari. To bad that pesky knob cracked. I thought that stuff only happened in my shop.

Cheers --- Larry

Joseph Pritchard said...

Great movie Kari! So, what is the significance of 1805? I've only done one fox wedge and didn't drill a hole. The chair rung didn't split; I got lucky.

Kari Hultman said...

Dave, this makes for a super strong joint if you taper the inside of the mortise to match the flare of the tenon. (See illustration). The one I made works great for smaller joints. I have made larger joints on step stools with through-wedged tenons (same thing, only it's exposed), have not tapered the mortise, and the joint holds great.

Larry, rest assured, you are not the only woodworker who goofs on occasion. :o)

Joseph, this is a drawer for a reproduction piece that has that year scribed into the front of the drawer. I don't know if the hole is completely necessary, but it makes me perspire less during assembly.

The Apprentice and The Journeyman said...

Kari...Well done! The tutorial, the video, the joinery, and the music is a joy to watch and to listen to.

The knob could well be in place by 2105.

You're raising the bar...keep it up.

The Apprentice and The Journeyman said...

Just a follow-up thought...(after sleeping on it.)

How would press-fitting the knob work?

By using a vice or a clamp the knob can be seated without chance of injury.

Kari Hultman said...

TATJ, press-fitting is an interesting thought. I guess the only thing you'd need to watch is that the clamping pressure is straight down, so that the knob is pushed in squarely. At least you would avoid the problem I had with cracking. Good idea!

LizPf said...

Kari, this is a wonderful video! Graphics, camera work ... I'd love a voice like yours ... if you ever have plans to do a podcast series, I'll be your first subscriber.

The fox wedging is cool, though I'd be scared to do it. I'd just rather make a through mortise and wedge where I could see it.

Kari Hultman said...

Liz, you can totally do this joint. This was my very first fox-wedged tenon. It's easy. You can always do a couple practice pieces until you feel comfortable.
Thanks for the kudos. :o)

Dyami Plotke said...

Sorry I'm late to the party. Spent the weekend trying to kill my jointer. But enough about me. This is a great video and instruction. Thanks so much Kari. I know how much extra work went into it's production, and I for one appreciate it.

mdhills said...

Thanks for the video. Wasn't entirely clear on how to determine the thickness/length of your wedge prior to tapping it in. I've got images of a partially-driven tenon that is locked in place, but where the wedge isn't fully seated. I always have to trim off excess when I'm working with (normal) wedged through-tenons.

BTW, have you been catching the woodnet thread on japanese hand tool use?

Anonymous said...

Workshops wonderful Kari, like a lady well have removed all the dust and put everything in order. When we see the dresser over? I like your tool cabinet and the songs of your videos, you must always write the song titles for us.
Tanke you
Ciao Vittorio

mdhills said...

That song was "Somewhere Over the Rainbow" by Israel Kamakawiwo'ole. I was hoping she would say the artist's name in the voiceover. :-)

So, I'm also wondering what's on your workshop itunes playlist.

Kari Hultman said...

Dyami, sorry to hear that your jointer is still out of whack. That's a bummer. :(

Mdhills, thanks for the link. I like that guy's leg vise. :D
Lots of other good videos on that youtube page.

Thanks, Vittorio. All I have to do is rub out the finish of this project and I can check it off my list. Finally! Glad you like the song. I see that the next commenter filled you in on his name.

Mdhills, I'd be filming for a week if I had to try to pronounce his name! haha My playlist is pretty eclectic. Just about every genre is represented except opera.

will said...

Not that it would have made a difference in this effort but I always chamfer the end of a dowel (or drawer pull) before installing it. That makes a pocket for excess glue.

You didn't say, did you saw off the pull, re-drill and install another pull?

Kari Hultman said...

I'm with you, Will, and I always chamfer the end of the tenon, too. I forgot to mention that. Although, I did also cut the tenon about 3/32" short to allow for glue squeeze out and room for the wedge to reach the bottom of the mortise without interference from a too-long tenon.

I did not turn a new knob; I just packed the crack in this one with dark paste wax. ; )

Douglas C. Bordner said...

Googling "Fox Tenon" gave you the top hit, Kari. Excellent presentation and as mentioned the honesty of not editing out the split was great in-and-of itself.