Thread: Leg - foot joints

I'd say what you have is perfectly fine, you can wedge if you want but it's probably overkill (which is the best kind of kill )

Originally Posted by elanjacobs

I'd say what you have is perfectly fine, you can wedge if you want but it's probably overkill (which is the best kind of kill )

+1 for this.

I have just done my first draw bored job on a table leg construction and it did a great job of tightening the joint without clamps and that was because our woodwork club didn't have enough clamps long enough to do the job, But as stated by elanjacobs how you are doing is fine.

Regards Rod.

Sounds like the answer to my last question is "yes"

Thanks fellers.

Hi Labr@,
Your joints are around the same size as mine, allthough mine may have been a little longer, around 65mm I think. I put the draw bore pins 30mm from the top. I did glue & draw bore, only because I like overkill. Keep the pictures coming.

Thanks for the further replies and interest.

Have done all the tenons, top and bottom, on the legs. They were done with a router and seem to have come up reasonably well although one leg needed 2 lots of rework due to not doing up the collet tight enough and having a guide clamp come loose.

Top and bottom joints are different sizes so marking out the tenons took some time. Finally set to chopping the first 1 today after watching a video on how do this during the week. It is one of the top pieces of the trestles as these are a little smaller then the "feet" and I think therefore possibly just a bit easier. I don't own many chisels but sharpened up a 1/2" one and set to on a 27 by 45mm mortise. The technique from the video works well although I've probably forgotten some of the finer points already.

The relative widths of the mortise and chisel were such that 2 rows of chopping fitted fairly well. For future reference should I be considering chisel size when deciding joint dimensions for something I'm designing?

Some pics of today's progress:

First row chopped right through, second row started.
Mortise partly cut.JPG

Fully chopped out.
Mortise cut.JPG

Test fitting after some tenon trimming.
Almost fits.JPG

Needed to do some trimming on the tenon with block plane and chisel and may need a little more yet but it is close. Hopefully they will become more accurate and neater with practice.

I'm coming in late, but the tenon sizes look adequate to me. I certainly wouldn't bother with draw-boring them, if you flare the bottoms of the through-mortises a bit, then saw slots in the tenons & wedge them at glue-up, I think you'll find that plenty strong & durable. That's what I did on my bench, which is around 30 years old now, & no problems so far....

You always get a bit slicker by the time you reach the last mortise (), but you're doing fine so far. It's far better to have an over-tight joint & have to sneak up on a fit than a loose one! Trimming the sides of tenons of this size is a job my Stanley 78 does extremely well, so if you have one, or can borrow one, give it a try....

Cheers,

I'll keep the wedges in mind Ian, I guess it will depend on how stable things feel once all joints are cut.

Did 1 of the larger mortises in the jarrah feet today. The timber is no harder to work than the kapur as far as I can tell but the extra depth made it a lot more work. I did find another chisel in a drawer today and that has helped a bit as it is longer and seems to keep an edge better.

OK, Rod, sorry for the no-pic reply. I don't have a sequential set of pics, so how about a simple sketch and couple of pics?

This diagram should explain how to prepare both tenon & mortise: Diag.jpg

It doesn't need much flare in the ends of the mortise, about 1.5mm sloping to nothing by about 1/2 the mortise depth is plenty for something the size of bench legs. I usually use the off cuts of the tenon cheeks for wedges. Either saw them, or better, split them out with a wide chisel & shave them to a wedge so the grain flows through the whole wedge & it is less likely to break when driven in.

Here are a coupe of wedges ready to drive home. These are fatter than I would normally use, because my mortise went a bit off in this mallet head, & I had to flare the hole a bit more to straighten it: Wedges.jpg

Once the wedges are firmly home, trim them off, plane the surface if it's going to show (or if like me you're just fussy), and you should end up with a neat joint that is bomb-proof, even without glue: Cleaned off.jpg

Hope that's a bit clearer than my quick description above.
Cheers,

Ian, is the ~1.5mm cut back on one side only or both?

Originally Posted by Lappa

Ian, is the ~1.5mm cut back on one side only or both?

It's only necessary to cut back the wedged side, Lappa. The idea is to jamb the tenon in the mortise by creating a flare on the tenon. If you do it right, you don't need clamps, and you probably don't need glue, but I always use glue, for extra insurance.

When you've mastered this method, you can move onto hidden or 'fox' wedges in non-through tenons.
You do much the same as shown above, but the mortise is sloped inwards, so it is wider at the bottom than the top (shoulder side). Then you have to measure the wedges & judge their thickness pretty closely, so that when you drive the tenon home, the bottom of the mortise forces the wedges in, expands the tenon and locks it in place. If the wedges are too thick, the tenon jambs part way in; too thin, and you have a loose joint that you can't get apart to fix! I've only done them a couple of times. It's a bit too stressful when it comes time to assemble - you only get one go at it!

Cheers,

In the picture examples you posted, you used two cuts in the tenon and two wedges therefore I assumed you were flaring both sides of the tenon therefore would need to cut back both sides of the mortise?
Cheers, Peter

Well I reckon it took over an hour and a half to cut and fit the second large mortise, with about half of that being the trimming and test fitting after doing the chopping.

And I enjoyed every minute of it. There's something ironic about smacking something with a big mallet as part of a creative endeavour and I kind of enjoyed that too.

Anyhow one trestle is now at dry fit stage. Not perfectly aligned unfortunately, but I'm happy with it considering my lack of experience.

Trestle 1 dry fit.JPG

Originally Posted by Lappa

In the picture examples you posted, you used two cuts in the tenon and two wedges therefore I assumed you were flaring both sides of the tenon therefore would need to cut back both sides of the mortise?
Cheers, Peter

Hi Peter, sorry, I misunderstood your question. I thought you meant, do I flare both the shoulder side and the 'exit' side of the mortise. If I'd stopped and thought a bit more, I should've realised what you were asking - my apologies! So the answer is, yes, I cut back both ends of the mortise, on the side opposite the shoulder. You could flare just one side, I suppose, but it's better to keep things symmetrical and create even pressure, I think. Hence the two saw cuts for two wedges.

Hope that clarifies things...