I thought I should post my wedged tenon because despite the fact that I am unhappy about the leg vise, I absolutely nailed the wedged tenon. I am unhappy about the leg vise because, unusually I copied it from a book. Normally I adapt things and add improvements to suit my needs. I had read every article I saw on leg vises, over a period of four years. That’s a lot of articles, in these articles not one person mentions the determining factor when designing a leg vise. It’s the screw height. I could easily have designed a better leg vise had I known about the importance of the screw height. Oh well I have learned the hard way I suppose.
I put together the pin board and the vise face, today. Its quite a technical joint because the component sits in a five mm rebate. The shoulder is hidden from view. There is a hole very close to the shoulder, by recessing the shoulder it should support the short grain behind the hole. I made a practice wedged tenon and it didn’t work because I didn’t account for the width of the saw kerf, this was such a valuable lesson. Test joinery is never time wasted in my opinion. So, I was very careful when choosing my saw to cut the kerfs in the tenon. I opted for a kerf of 0.7 mm. I have a different saw with a 1mm kerf, if I had used the 1mm kerf the wedges would have bottomed out before closing the joint. I have found it is not a joint which can be exactly calculated prior to assembly, it requires a level of intuition. If you calculate that you have 4 mm of taper plus kerf, the wedge needs to provide 4 and a bit mm. The tolerances are extremely tight and the difference between a great joint and a disaster are minimal. I always stress because of this. You can play it safe and accept voids within the joint but I prefer to try and do it well. Anyway the ideal is to have no voids inside the joint and that is exactly what I achieved. When the dark line on my wedges is about a mm above the top of the potruding tenon the wedge is about two mm from the bottom of the kerf. As you can see, I have fully seated the wedges and tightly closed the joint. When I glued up and whacked the component to seat it in the 5 mm recess, the part seized up and I couldn’t seat it ( only about 30 seconds had elapsed after application of glue). Putting the wedges in pulled the unseen shoulder tight and there was a lot of squeeze out from the wedge side of the joint. That’s exactly what I want to see when I am wedging a tenon. If the parts are properly fitted the wedges should produce a lot of squeeze out. The end result of all the attention to detail is a perfectly square pin board, in both planes and, its incredibly strong of course. It was a little stressful but very satisfying. I love gluing up at home because I can get very organized and work fast. So I had a good day today.
I was thinking about how I was stressing out over this bit of joinery. I realized there is a foolproof, no maths required way of getting perfect wedged tenons. Simply lay out the mortice using a bevel gauge, save the setting on the bevel gauge to make a perfectly matched wedge. Then cut the kerfs in the tenon using any saw you like. Now trim the pointy tip of the wedge until it is just a bit wider than the saw kerf and it will fit perfectly, every time. It takes into account, the width of the saw kerf, regardless of its width.
Lovely work as always Giles, nice one and great write-up! 
Cool
Looks really nice - and solid.
Glad to see it’s coming along, the wedge looks great!!
What’s the toothbrush for?
Cleaning away squeeze out.
I am just adding a picture of the trimmed joint.
Yeah, it’s very accurately fitted, no undercutting, I can’t imagine how much force it would take to make the joint fail.
The ramekin with the w is slightly watered down glue which I apply to the first half of the joint to be glued up. Full strength glue on the other half of the joint. Clever people have done research on glue failures and the number one cause of glue failures is dry joints. The optimal amount of glue for a strong joint is just 3 microns, one on each side and one in the middle. Not a lot of people know that!
Nice work as always!
Yes, its a success to be sure.
I just have to attach the top now.
Lovely work.
nice one Giles
That is a thing of beauty.