What joinery can I use to join the halves of workbench stretchers (2x4 studs)?

[Minh Tran]

Hi again Creekers!

Attached is a picture of my workbench design. It's a little deceptive in that it doesn't include details about the type of joinery used. Also, it doesn't include the cabinet & drawers that I plan to build and place in between the top and bottom row of stretchers. The stretchers are joined to the trestle legs using through-mortise & tenons.

Though I haven't glued the frame together, I intend to glue the stretchers & their tenons to the trestle leg mortises. This creates a permanent frame. I'd like to make it more transportable and plan to cut down center each stretcher.
Before I do that though, I'd like to know if there any joinery that I can use to join the two halves of a stretcher.

Each stretcher came from a 2x4x8' stud (a wee smaller since the surfaces have been planed & jointed).

---

I guess the problem simplifies to 'what joinery do I use to join two 2x4's together the long-way'.

Thanks in advance!
MT

[Jim Becker]

If you need/want knock-down, I suggest you reconsider your joinery for the long stretchers into the footed ends. Unglued through tenons, wedged and pinned can be sturdy with an ample shoulder and knock down later when you need to do that. You could provide additional removable support to help insure you don't get racking without compromising the knock-down capability.

In other words, I cannot imagine any way for you to "halve" the stretchers that would be sturdy enough for the intended purpose of this bench. But that's my brain and perhaps I'm just not seeing an alternative.

[pat warner]

Face to face joinery? Then 1 or 2 splines to keep the stock from squirming when you glue up.
And large (>or = 5/16-18) joint connector bolts for KD assembly.

[Wayne Lomman]

There is no end to end joinery that will work successfully. Do what Jim said and make pinned/pegged loose tenons. It will be much better. Cheers

[Bradley Gray]

I made a trade show display last month and used cross thread dowels:

cross thread dowel.jpg

Very strong and fairly easy.

[Jerry Miner]

I'm with Jim and Bradley--- make a knock-down connection at the stretcher-to-leg connection, rather than at the middle of the stretcher.

A shallow, unglued tenon, with a cross-dowel connector will be strong and dis-assemble-able.

Lee Valley sells a heavy version of Bradley's cross dowel: Lee Valley

[Brian Tymchak]

In Rough Cut 413 (Garden Bench), Tommy Mac used a wedged scarf-joint (my name) to join 2 halves of a stretcher on a garden bench.

Never done it myself so I can't vouch for strength of joint but it is pretty neat and I look forward to using it in some project.

However, I agree with others - I used wedges with through tenons on the base stretchers of my workbench - closely patterned off of the 21st Century Workbench from Bob Lang when he was with Popular Woodworking.

[Robert Engel]

I used these Stretcher bolts on one bench and on another I simply used a long bolt and captured nut.

You could use thru tenons & wedges.

[peter Joseph]

The only joints I've seen that would serve your purpose have been very complex japanese joinery methods. Even then, I don't believe they are designed to be taken apart and put together again and again. I would use tusked tenons into the legs.

Do you plan to transport your bench often? Do you have the room for a permanent bench as well as a knockdown bench? Chris Schwarz has an article in PW that details a 175$ knockdown english bench that looks very stout. May be worth a look.

[Prashun Patel]

Cutting the stretchers in half won't make it as portable as making the mortise/tenon joints knock down.

Just to stir the pot, consider how often you are truly going to move this. If you plan on moving ONCE, then just glue in your stretchers to the mortises permanently. When you move, cut off the stretchers and get a couple new 2x4's and redo the joinery.

[Myk Rian]

Why would you want to cut the stretchers? Stow them away with the top, which appears to be longer than they are.

[Robin Frierson]

I have a workbench where the strechers are connected by dowels but the real strength comes from threaded rod which run in a dado inside the strectchers through the legs where there is a nut recessed into the leg. My entire bench is buit with that threaded rod. I glued my dowels in but you could leave them dry and just use the threaded rod. The bench is under compression and very rigid. I made it in 1996 and it has been moved several times too and as remained very tight and sturdy.

[Minh Tran]

Cutting the stretchers in half won't make it as portable as making the mortise/tenon joints knock down.

Just to stir the pot, consider how often you are truly going to move this. If you plan on moving ONCE, then just glue in your stretchers to the mortises permanently. When you move, cut off the stretchers and get a couple new 2x4's and redo the joinery.

Great point. I don't need to move it out of the apartment often so redo-ing the joint isn't a big deal. Second time around, I'll reconsider the joinery and use the bench bolt or half-laps.
In all likelihood, though, I think I'll glue the tenon to the through mortise for the reason you mentioned. I don't want to drag this project out anymore than I need to.

I'm with Jim and Bradley--- make a knock-down connection at the stretcher-to-leg connection, rather than at the middle of the stretcher.
A shallow, unglued tenon, with a cross-dowel connector will be strong and dis-assemble-able.
Lee Valley sells a heavy version of Bradley's cross dowel: Lee Valley

Neat idea... So for this kind of joint:
1. Use a forstner bit to dig out a shallow hole in a leg, on center with the stretcher tenon. Come back with a brad-point to drill a hole through the leg into the stretcher tenon.
2. Use a forstner bit to dig out a hole in the stretcher, intersecting with the hole drilled in (1), for the cross-dowel connector. Stop when the brad-point hole is visible.
3. Thread a rod through the brad-point hole into the cross-dowel.

Did I miss anything?

In Rough Cut 413 (Garden Bench), Tommy Mac used a wedged scarf-joint (my name) to join 2 halves of a stretcher on a garden bench.

Never done it myself so I can't vouch for strength of joint but it is pretty neat and I look forward to using it in some project.

However, I agree with others - I used wedges with through tenons on the base stretchers of my workbench - closely patterned off of the 21st Century Workbench from Bob Lang when he was with Popular Woodworking.

Thanks for sharing the video! That joint looks awesome. I'll have to use it in another project, though since it seems a bit overkill. But I think it definitely would give a strong joint. (I'll have to test it on a 2x4 but I'll keep you posted if the connection is strong!)

If you need/want knock-down, I suggest you reconsider your joinery for the long stretchers into the footed ends. Unglued through tenons, wedged and pinned can be sturdy with an ample shoulder and knock down later when you need to do that. You could provide additional removable support to help insure you don't get racking without compromising the knock-down capability.

Is it possible to put a wedge in a mortise set inside a 3/4"-wide tenon? How wide should I make the mortise?

[Jim Becker]

Is it possible to put a wedge in a mortise set inside a 3/4"-wide tenon? How wide should I make the mortise?

The tenon on a stretcher like that would typically be most of the thickness of the stretcher and be adequate for a mortise for a wedge. You don't need substantial shoulders.

[Minh Tran]

DOH! I just started resawing them to 3/4" ...

I should have just widen my mortises