Furniture joint

[^woody^]

Any bright ideas how to make this joint?

This will be part of an arm of a chair, with the round 50mm section being upright so may get a bit of leverage force applied when in use, and the flatter sections being part of the seat. The grey thing is the same joint but viewed from the underside of the corner.

I'll mitre and either spline or dowel the joint between the bottom two sections, and was just going to dowel the upright piece. But I wondered if just a dowel would be sufficient?

Alternatively perhps a longer steel rod of some sort, and maybe attached to a metal plate on the underside? Not ideal as I would not really want a plate visible.

And while we are at it, any recommendations for the best, strong hardwood furniture glue?

 

[johnny2007]

Not clear what you want to do, maybe another sketch would help.
I use everbuild d4 wood glue for most furniture joining applications and it holds very well while at same time giving you about 10 minutes before it grips.

 

[^woody^]

Not clear what you want to do,

Fix three pieces of wood to form a corner - imagine x/y/z axis

This will be the front corner of a chair to hold the chair arm. My concern is that the upright (the 50mm round piece) is going to get some force applied to it in use because its the chair side arm, and this may well strain the joint.

So the question is does the joint need to be reinforced with something more than the dowel I intended to use.

This is the principle - although not the actual design, as the timber I will use is round or rounded at the mitre

 

[Burnerman]

Maybe consider this fixed to the base of the upright:
https://www.screwfix.com/p/easydriv...thread-dowel-screws-m8-x-x-75mm-10-pack/7618h
The machine thread could pass through a triangular plywood web on the inside, with washer then nut.
There's a lot of stress on that upright!
John

 

[foxhole]

Ideal you need a square timber that’s turned above the joint so join is all square timber .

 

[mrrusty]

As you say, it's going to be a stressed joint. I think if I was doing this I would make up the frame joint as strong as possible, and a spline sounds a good option. Or possibly two thinner splines with a gap between (to allow for the other fixing). For the round upright I think I would try a crossdowel in the upright and a bolt from inside the frame. You might even be able to angle it a little to get the dowel itself into the meatier part of the upright. The bolt will allow you to pull the joint very tightly together. The adhesive depends a bit on what timber you are using. If it is hard/not very absorbent I wouldn't use a PVA. Perhaps PU or even epoxy.

 

[Ryler]

You can make them with the Festool domino...
https://www.manualsdir.com/manuals/103373/festool-domino-df-500.html?page=18

 

[Burnerman]

Well clever, that one....I'm wondering whether small dowels would be good enough in a domestic situation such as a couch though?
John

 

[johnny2007]

I would use dowels and glue, then reinforce everything with brackets in the inner hidden points.

 

[^woody^]

Well clever, that one....I'm wondering whether small dowels would be good enough in a domestic situation such as a couch though?
John

Yes that's what thinking.

That was more or less exactly what I was going to do, but with dowels. Part of me is saying that if everything is nice and tight and glued up properly, then it should not come apart because there is no allowance for movement. But the part of me that typically does the over thinking is saying it needs something longer or of metal going up the vertical piece.

 

[^woody^]

You can make them with the Festool domino...
https://www.manualsdir.com/manuals/103373/festool-domino-df-500.html?page=18

Thanks for that. If I could do a "like" and a "thanks" I would.

I must have looked for hours for a name of the joint and an example.

My plan was to make the joint with the square sections first, than router them to make the round and the rounded pieces before gluing them up.

Do you think those dominos are stronger than dowels? I certainly won't be buying a domino router, but that's sent me in new directions for alternatives.

 

[^woody^]

I would use dowels and glue, then reinforce everything with brackets in the inner hidden points.

Normally yes, but I'm not feeling brackets on this one even if hidden - it needs to be a bit prestige.

 

[Burnerman]

Yes that's what thinking.

That was more or less exactly what I was going to do, but with dowels. Part of me is saying that if everything is nice and tight and glued up properly, then it should not come apart because there is no allowance for movement. But the part of me that typically does the over thinking is saying it needs something longer or of metal going up the vertical piece.

For sure, reinforcing the vertical piece is a good move, but that will only transfer any force to one of the other joints - failure will find the weak spot!
John

 

[big-all]

my thoughts
if you can move the dowel perhaps 75-100mm away from the mitre you will have the opportunity to have the choice for 2 joints giving the best you can get with the interaction area being the maximum rather than in your drawing with a dowel being about 30% face contact and only half depth [1/3-1/6th ]possible strength between dowel and mitre also detracting from the mitre by perhaps 20%
where as a dowel inserted all but 10mm into a hole or mortice will give maximum strength with say 20% loss eventually when the glue lets go with wear and tear
where as an open dowelled or biscuit joint will loose perhaps 70-80% off strength and resistance to active load

 

[Ryler]

Don't feel restricted to wooden joints.
Many designers incorporate metal work in their joints. What makes it work is the quality of the craftsmanship.