I need some advice from some skilled wood workers on a planned mortise and tenon joint. I’m beginning to work on my third workbench (over 30 years). This one will be a good traditional maple block bench. I’ve bought the laminated block and the 8/4 maple (killer on the wallet!).
I’m planning to make a trestle base with double wedged tenons (a’ la fine woodworking). I’ve used them several times over the years for critical applications with durable results.
My worry here is that I plan to tenon the stretchers into the legs giving me a 4″ wide double wedged tenon (the stretcher is 5″ wide). Is the tenon’s shrinkage across the grain in a with-the-grain mortise going to loosen up? I’m in central California where wood movement is nowhere near as extreme as it was indoors in New England.
Edited 6/5/2003 12:31:14 AM ET by telemiketoo
Replies
Don't know, but afriend made his with off centered bored holes and smacked flattened tapered oak wedges. The better to disassemble I guess?
Stein.
I think the wedged tenons will provide a mechanical way of keeping it in the mortise and the wood movement at 4" width is probably insufficient for the tenon to dislodge from the mortise. However, whether it might become loose I cannot be certain. Forgive me for being dense, but are you gluing this joint or are you relying on the wedged tenon to make the connection?
I have a workbench plan with a trestle base that calls for a stub tenon on the stretcher that goes into a shallow mortise in the leg. The joint is then reinforced with a draw bolt. A through hole is drilled into the leg on the side opposite the mortise. The hole goes through the mortise and into the tenon and stretcher. Another hole is drilled into the face of the stretcher that intersects and is perpendicular to the original hole. A bolt goes through the leg and into the stretcher and then is captured by a nut inserted into the hole in the stretcher (plus whatever washers necessary). The whole idea is that from time to time, one can snug up the joint, especially with humidity change or when the workbench sees a lot of action and the resulting stresses start to loosen the joint.
I'll be gluing the joint with titebond. The wedge should be the main strength, but the glue will help considering the forces a bench sees.
I've considered the drawbolts and even have a nagging suspicion that I should use them. However, I want this to be a wood bench. Maybe I'll have to find a way to add the bolts later!
By the way, the top is the Veritas 2 3/4" thick laminated maple top. What a heavy solid chunk! When I'm through, it'll take a big crane to move it!
I've been slowly working on my shop (my wife thought it was a "garage"!! Ha Ha.) I've moved the dust collector and the air compressor into a new attached closet outside and put in good piping. I've drywalled and painted two walls already and the lightening makes a huge difference. Just the phsycological boost alone is worth the work. The bench is next. It won't be done until winter because it's summer and I've got to work the orchard (180 Pistachio trees) and re-side the garage this year.
Looking forward to retiring in a few years. I had hoped that the grand state of confusion would offer early retirement to get rid of some of us old timers, but the budget isn't very good and the two sides don't seem to be very interested in compromise to make the government work. But, that's another story.
Telemike,
I may be confused here...but isn't the shoulder on the stretcher against the leg going to be a major source of stability...and moisture won't effect the tension you create between the shoulder and wedges on the end of the tenon...
I went witht he draw boltg, through a stup tenon, which allos both disassembly, and periodic retightening. It has worked well, and I would recommend it.
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