Strongest joint

[worldofwood]

I'm fairly new to woodworking and need to know which is the strongest form of joint to construct the design in the picture.
Its a basic design with chunky beams that are 20cm wide. I was originally thinking mortice and tenon joints but I want to keep the original 20cm width of the beams for the legs and table top.
I don't really want anything showing on the top surface (dowels etc..). Would some type of biscuit joint do the job (a really chunky one) perhaps?
Any ideas much appreciated.

 

[marcros]

I would probably just put dowels for location into the top side of the legs and the underside of the top. Rely on gravity for the rest

 

[worldofwood]

cheers, how many dowels along the length of the leg do you think? also what thickness for the dowels?

 

[barkwindjammer]

I would epoxy some short lengths of screwed rod into it.

 

[Jacob]

At Stonehenge they just did short stub tenons.

Hope that hepls.

 

[worldofwood]

I think i will go with dowels in some form rather than lose height in the legs to make tenons. Seems like the quickest way is to drill holes and insert dowels all the way along.

If I drill corresponding holes under the worktop and insert dowels as well as glue all along the top surface of the legs would this be strong enough?

 

[marcros]

i would probably just go for a couple of something large in the leg- to make the 5th dice spot where you have drawn your 4- broom handle would do. i am suggesting only using it as a locating device. An inch sticking out of the leg will do. I would also leave a deliberate gap between the top beams, to save you having to get them as a perfect mating surface.

have you got the timber for it? what are you using?

 

[worldofwood]

Yep I think a slight gap between the two beams is a good idea. I was thinking of using oak.

So if if I have just two central holes an inch deep with broom handle width dowels (2inch long) inserted as well as the entire top of the leg glued up is that about right?

 

[marcros]

i wouldnt glue it. just glue the dowel into the legs, and leave it at that. 8" oak is going to be heavy. not sure how long it is, but I know how heavy lumps of oak sleeper are, and they arent going to go far with an accidental knock. It will also enble you to move the thing if you need to.

Make sure you have a suitable drill bit for your dowel. probably easier to size a dowel to a drill than to try and find an obscure drill. Try plug it dowel for instance.

How are you planning on flattening the pieces? There is a good article in one of the fine woodworking magazines where they use a router sled to flatten and square stumps. What have you got in the way of tools?

8" seasoned oak may be interesting to try and source...!!

 

[Harbo]

What is it - an elephant's footstool?
It's going to be very heavy and if the wood is not properly seasoned will warp like anything?

Rod

 

[worldofwood]

It might not be the most subtle design in the world but they are quite a few around like this below made from green oak so its not a hypothetical question.

I like the idea of just having the bottom of the dowels glued into the legs so you can slot the table top on and off easily.

p.s I have various hand planes for flattening.

 

[Duncumb.fc]

Rub joints are surprisingly strong, clumsy as they seem!
Simply fit the edges (perfectly) using a jointer, and put in your poison of choice. (Titebond works great, animal glue is more fun!)
Clamp one half in the vice, gluing surface up, and put the other bit on. Rub it backwards and forwards along the length of the wood until you can't move it anymore. (Think of squeezing all the glue out of the joint.)
At that point leave it to dry, no need to clamp, you'd have quite a job taking such large pieces apart after doing that!
Clearly this would be best for jointing the top, not the legs. Dowels give you the removable legs as mentioned above!

Fraser