Joinery Design Question

[Dave Richards]

Greetings,

I am working on a design (gathering design ideas from all sorts of sources) for a workbench and have a question about the leg to stretcher joints. Maybe someone would have some insight.

This morning an image popped into my head of the stretchers being joined to the legs with large through dovetails. I'm thinking of both the short and long stretcher joining such thtat hteir ends meet in a miter. Tails would be cut on both stretchers and the pins would look sort of like the keyed dovetails sometimes used to strengthen miters on boxes.

What do you experts think? Would this be a sound method of joining the pieces?

[Marc Wittman]

If I'm understanding correctly, I'm not sure a dovetail would be the best joint. In this joint, the 2 pieces to be joined are meeting at a 90 degree perpendicular angle. I would only use a dovetail when joining boards that come together in a parallel fashion. If anything, I might use a sliding dovetail for a stretcher or apron to a leg. I would advise a mortise and tenon or a bench-type bolt. I'm by no means an expert on bench design, but I don't think a d/tail would give you proper strength.

Just my 2 cents.

[Dave Richards]

Maybe I didn't explain myself clearly. The pins would be cut in the leg; The tails in the stretchers. There would actually be pins cut on both outside faces of the leg and the stretchers would be flush with the outside faces of the leg. Both the short and long stretchers would be the same distance from the floor so they would meet at the outer corner of the leg. Thus they'd be mitered (beleveled) at their ends.

I'm also thinking of gluing these and using no hardware.

[Mark Mazzo]

Hi Dave,

As an aside, we're both from Rochester, but I'm in New York ;)

Regarding your idea on joining the stretchers to the legs with dovetails, I think that it could work but you would need a leg at least twice the thickness of your stretcher. That way you could do the through dovetail across one dimension of the leg, but dovetail would only occupy half of the other dimension of the leg (probably hare to visualize).

However, a couple of things to consider for a workbench base are:

1) whether you ever intend to move it (i.e. any need to take it apart).
2) whether the repeated pounding will require the legs to be periodically tightened.

Because of these two issues when I made my workbench I used a tensioned truss rod to hold the leg assemblies and stretchers together. All of the joints are butt joints and the rods sit in dado's along the length of the workbench base pieces. These rods can be periodically tightened if the joints loosen due to pounding or wood movement by just tightening a hex nut on the ends. Also, if I ever need to move it I can disassemble all or part of the workbench base. My bench is patterened after the Veritas bench by Lee Valley. With the truss rod design it is very easy to apply tremendous amounts of pressure to keep the joint tight with very little effort.

I know that this is very different from what you were thinking about, but I thought that I'd point it out as an option. I have been very happy with the performance of my bench using this system.

Good luck on your project.

-- Mark

[Dave Richards]

Mark thanks for the thoughtful reply. As to the leg and stretcher dimensions, I was thinking that the leg would be at least twice the thickness of the stretcher. I guess I'm not so worried about future disassembly but your point about tightening the joints as the bench ages make sense. Probably back to mortise and tenon joinery.

I was thinking of making a tail vise with the assembly dovetailed as is common and thought that echoing the dovetails down on the leg could be a nice design feature. Maybe that's something better left for something like a sofa table.

I bet your Rochester is a better place to get woodworking supplies and tools than mine. :p

Have a great weekend.

Dave