Wedged through tenon

[PerranOak]

So, I want to do a wedged through tenon. I'm using softwood and the tenon will be about an 18mm "cube" in shape.

I presume that I cut the wedge along the grain so as to "open up" the tenon in a natural way? The grain on the mortice side will be at right angles to the wedge?

Now. Do I have to make the mortice a sort of dove tail shape to take the wedged tenon? How thick (at each end) should the wedge be in this case.

Thank you very much for the guidance.

Cheers.

 

[Philly]

P
You want to split the tenon so that the wedge will press against the end grain faces of the mortise (if that makes sense) Putting it the other way can split the mortise piece.
And yes, you need to splay the mortise to give the wedges something to expand into. How much? By the amount your wedges need - so make wedges first then use these to lay out the mortise.
Hope this helps
Philly
(who has just finished wedging on a hammer head)

 

[Steve Maskery]

PO

When cutting wedged tenons, especially if they are for visual appeal, it it vital that you lay out the joint carefully.

You are absolutely right to suggest that the mortice should be dovetail shaped - it doesn't have to be by very much. Use a sliding bevel and draw o nthe outside where the walls of the mortice are to be cut. Make sure that you don't over-do the cutting, the inside end must be untouched. You can stop the flare a bit short if you want to.

Then cut the tenon. You will be able to tell from your layout lines, how big the wedges need to be. They need to be a bit longer than the length of your flared section. You don't want them to bottom out before they have filled their gap.

You have two options of where to put them; you can either drive them down the ends of the tenon, between tenon and mortice. A better option, however, is to make a saw cut down the tenon and insert the wedge into that. Mark it out and drill a small home, say 2mm, where the cut will stop. This will reduce the risk if breakage when you drive home the wedge. The saw down to the hole. Assemble the joint and drive home the wedges. You should arrange it so that the area of wedge showing is the same as the tenon area between it and the mortice, and of course, both wedges should look the same.

That's a start, others can add the finesse
S

 

[woodbloke]

As Steve has said, some careful thought needs to go into how you set out the joint and splay the tenon, I usually go for 1mm at each end. It's important that when the wedge gets to the bottom of the saw cut, it's splayed the tenon by the offset, in my case a mm. Best way to make wedges is using a jig on the bandsaw and they need to be identical. It also helps to make them from something hard and dense (ebony is good ) so that it's then easier to tap them in at glue up time - Rob

 

[CHJ]

A Google for "wedged tenon design" turns up a few examples/variations.

 

[joiner_sim]

Use this joint more or less everyday of the year, on doors & window casements! Everyone has pretty much covered it really. As it has already been said if its mean't to be decorative try and make it match. So your tennon wedge cuts need to be in exactly the same place as the others. I wouldn't worry too much about making sure the wedge fits all the way in. I would make the wedge the length of the tennon and bout 10mm wide at the end> use a jig on the bandsaw for this. Just make sure then that wedge room you cut into your mortice is identical, the wedges should all be about the sae size when tapped in until they stop. If you are using a morticer.... to cut the wedge room, cut out your mortice first, and then cut to the wedge room marks, which normally only need to be about 3mm wider than te mortice cut. Bring the morticer down and slowly move the cut to slope. Should only really be about half way long.

 

[Steve Maskery]

Here, in true Blue Peter style, is a sample I made recently:

I didn't get the proportions of the wedges quite right but other than that it is good and tight.

Cheers
Steve

 

[MarkT]

Been hanging around here for a while...thought it was time to join in...here's some wedged tenons I just did.

Sample of double wedged tenon:

Marked out to widen the mortice:

Decided to go 12mm down and 3mm wide on each wedge - so transferred angle to sliding bevel and then to saw blade to cut a block for chisel to run down:

Like this:

To get this:

[/img]http://lh3.ggpht.com/_aw9EEeh-gvM/SXD3Wdp1VvI/AAAAAAAAAQM/M-Iz9wfNs6U/s640/SDC10422.JPG[/img]

Here's a sample one with slits cut in tenon:

Wedged to be driven in:

After gluing and planed flush:

Cut in half for fun!:

In the end I wasn't able to do them this way in my actual piece - because of a blatant miscalculation the tenons didn't protude enough and would have gone below surface when wedged - so I wedged on the outside instead:

I did some diagonal ones too - no need to widen the mortice on these ones:

Anyway...hope that's of interest. Keep up the great work on the forum guys...always worth a good read.[/img]

 

[CHJ]

Been hanging around here for a while...thought it was time to join in...here's some wedged tenons I just did.

Sample of double wedged tenon:

Marked out to widen the mortice:

Decided to go 12mm down and 3mm wide on each wedge - so transferred angle to sliding bevel and then to saw blade to cut a block for chisel to run down:

Like this:

To get this:

[/img]http://lh3.ggpht.com/_aw9EEeh-gvM/SXD3Wdp1VvI/AAAAAAAAAQM/M-Iz9wfNs6U/s640/SDC10422.JPG[/img]

Here's a sample one with slits cut in tenon:

Wedged to be driven in:

After gluing and planed flush:

Cut in half for fun!:

In the end I wasn't able to do them this way in my actual piece - because of a blatant miscalculation the tenons didn't protude enough and would have gone below surface when wedged - so I wedged on the outside instead:

I did some diagonal ones too - no need to widen the mortice on these ones:

Anyway...hope that's of interest. Keep up the great work on the forum guys...always worth a good read.

Welcome to the forum Mark, you got caught by the spam trap, it will leave you alone after a few posts.

 

[joiner_sim]

welcome to the forum.

It all seems alot of fuss over a wedged mortice and tennon joint. Just make the wedge room, the wedge space, and bang the thing in! Job done! I think it's actually the easiest and maybe ugliest joint around!

 

[Mr Ed]

I can't agree with it being the ugliest, I think it can be an attractive joint personally;

Cheers, Ed

 

[Imperial]

Some more variation for good measure :twisted:

Elm with Rosewood wedges, all mortise tenons and wedges made with hand tools, would have liked them to be a little thinner though!

 

[woodbloke]

Here's how I do mine:

Tenon raised and rounded, wedge in rosewood - Rob

 

[Steve Maskery]

Very, very nice, guys. I'm rater ashamed fo mine now! But it was only a test, honest.

Rob, how did you shape that? Do you take any particular steps to avoid marking the stile?

Cheers
Steve

 

[wizer]

certainly NOT and ugly joint. Something I aspire to

 

[woodbloke]

Very, very nice, guys. I'm rater ashamed fo mine now! But it was only a test, honest.

Rob, how did you shape that? Do you take any particular steps to avoid marking the stile?

Cheers
Steve

Steve - shaping done with skew chisels (end grain) and long grain done with a shoulder plane with zero projection of the blade on the side, then lots of careful sanding :wink: - Rob

 

[marcus]

EDIT

ah you answered that above, I missed it!


______________

Nice, tenon Rob! Would you be willing to share what procedure you use for rounding over the protruding bit of tenon - I never get mine as neat as I would like :?

Thanks

Marcus.

 

[PerranOak]

Wow!

You guys are mega! My pathetic attempt will be an embarrassment!

I'm astonished at the width of some of the wedges. Doesn't the tenon/rail split down to its boots!?

Not sure how I'll make the wedges - I don't have any kind of powered saw.

 

[Steve Maskery]

I'm astonished at the width of some of the wedges. Doesn't the tenon/rail split down to its boots!?

I drill a small hole at the bottom end of the saw kerf to stop it splitting. And personally I would try to keep the flare and my wedges as fine as is possible consistent with doing the job.
S

 

[PerranOak]

I drill a small hole at the bottom end of the saw kerf to stop it splitting.

Oh yes, you did say that above, sorry, I forgot - I'm always forgetting(!)