Thread: A "make it up as you go" bench

Originally Posted by Islander

Do the wedges really hold or is it the type of timber you use.

I could be wrong but I think the most important thing is to have the tenons fit tightly in the mortises. I don't mean sledge hammer tight but I did need to tap mine on with a mallet. This stops wracking which I think is the most destructive thing with benches. The wedges do help to hold the tenons in place but if the fit of the mortise and tenon joint is sloppy then I suspect that the wedges would suffer.

The wedges I used are fairly flimsy looking but I think that for the application they will last a long time. It's probably more important to have sufficient tenon length past the wedge to avoid stripping out the centre.

I'd be interested to hear opinions from more experienced people on this.

Originally Posted by labr@

I could be wrong but I think the most important thing is to have the tenons fit tightly in the mortises. I don't mean sledge hammer tight but I did need to tap mine on with a mallet. This stops wracking which I think is the most destructive thing with benches. The wedges do help to hold the tenons in place but if the fit of the mortise and tenon joint is sloppy then I suspect that the wedges would suffer.....

Having used tusked tenons a few times certainly doesn't make me an expert, Bob, but I can vouch for their longevity if reasonably well-made. I've come across some very old ones which have held up remarkably well. I think it's a great joinery system, but it has a downside in that you've got a couple of potential shin-barkers if they stick out too far!

I'd have to disagree with your assessment of the function, slightly. I see the important part of this arrangement being that the wedge pulls the shoulders of the tenon against the leg and locks the joint principally in that direction. Of course it's desirable to fit the tenon as neatly in the mortise as you can, it will add to stability (and you won't be ashamed to show them off to other woodies! ). However, it will actually work quite well even if the fit of the tenon is a little loose, as long as the wedge can pull those shoulders tight. The idea is supposed to be that any loosening of the wedge caused by seasonal moisture changes is automatically taken up by the wedge wriggling back down if the joint moves in use. Which makes you wonder when you see these joints reassembled with the wedges inserted from the bottom, as I have on more than one occasion. Obviously not a lot of thought put into the process.

Originally Posted by labr@

...The wedges I used are fairly flimsy looking but I think that for the application they will last a long time. It's probably more important to have sufficient tenon length past the wedge to avoid stripping out the centre....

I think your wedges look pretty adequate. I agree on the second point, though how much wood you need to have past the wedge mortise is hard to judge. I tend to err on the side of overkill where I can. But my experience with wedging chair legs & through-tenons close to edges suggests that as long as the wood is sound to start with (no hairline splits), it takes a lot of force to wedge out 30mm of wood. I've tried a test-to-destruction on a scrap of the same wood I was using a couple of times, and the result was quite reassuring....

Cheers,

Originally Posted by IanW

I'd have to disagree with your assessment of the function, slightly. I see the important part of this arrangement being that the wedge pulls the shoulders of the tenon against the leg and locks the joint principally in that direction.

I can't argue with you Ian - your view of it makes too much sense .

My tenons are extra long for overkill too but are still under the bench so mostly out of the way - although I did need to trim 1 to fit the vice.

The upper tenons have the wedges driven in form underneath so I can tap them in more if they do become loose. They are too close to the bench top to knock down from above.

Originally Posted by labr@

......The upper tenons have the wedges driven in form underneath so I can tap them in more if they do become loose. They are too close to the bench top to knock down from above.

I see your problem, Bob. I would've put the wedge mortise in cross-wise in that situation, if I possibly could. They'll work either way. Still not 'ideal', but should be a bit better than having gravity and moisture cycles working agin you. There's a good chance my fears are groundless. The top joints should experience the least movement and the wedges will probably stay put for many years after I've ceased to read this BB. (So you won't be able to say "I told you so "), but at least you'll have the satisfaction that your solution was fine...

If there is a problem, try the solution a young friend of mine recently taught me (thankyou, Luke ) - use some hair-spray on the mating surfaces. He says he saw it in a 'handy hint' somewhere for keeping socket-chisel handles in place. Haven't tried it yet, but it sounds like a good idea. My advice: just make sure you return the hair-spray before the rightful owner gets home or you could have some difficult explaining to do....

Cheers,

smick looking bench

Originally Posted by IanW

My advice: just make sure you return the hair-spray before the rightful owner gets home or you could have some difficult explaining to do.... Cheers,

We had our 35th wedding anniversary earlier this week so I understand exactly what you mean!