Mortice and tenon advice for table leg

[fobos8]

Hi all

Reading a few bits and bobs it apears that when doing mortice and tenons for rails going into a table leg the done thing is to offset the mortice towards the the outside so you can get a longer tenon.

What is the closest you ought to go to the outside of the leg before the mortice becomes weak? Is there a rule of thumb?

Also, whilst I'm at it how many people put a haunch in tenons for this sort of application?

Best regards, Andrew

 

[cerdeira]

Hi,

What is the closest you ought to go to the outside of the leg before the mortice becomes weak? Is there a rule of thumb?

You mean the mortice wall? I wouldn't go for less than 6mm or so.

Also, whilst I'm at it how many people put a haunch in tenons for this sort of application?

I do.

 

[OPJ]

On a dining table, I'd be inclined to make it closer to 12mm at least, as it's more likely to get dragged around the kitchen floor and 'abused' by seaters and guests.

Definitely include a haunch. Otherwise, you either have a bridle joint or, a very weak but small area of timber at the top of the mortise - I don't understand why Americans seem to do this, though? :? A haunch will help to prevent the rail from twisting over time.

Another general rule you may find useful is that the width of a tenon should not exceed five-times its thickness.

...Won't be long now until we have to give you your own forum, Andrew, with all these questions!! :wink: (Only joking!)

 

[fobos8]

...Won't be long now until we have to give you your own forum, Andrew, with all these questions!! Very Happy Wink (Only joking!)

Thats a great idea! I can't tell you how much I appreciate everyone's time to help me out. I wish I'd got into more joinery when I was younger - I'm facinated by it but don't have a great deal of knowledge.
Cheers, Andrew

 

[Chris Knight]

Also remember that you have a choice of a mitreing the tenons or using a cogged joint if you want a longer tenon.

 

[wizer]

or you could just buy a domino..... :lol:

 

[fobos8]

could I use a "domino" joints for a dining table?

My mate at work has one but I'm not sure it would be strong enough for a table of this size. 1600 x 900 x 40mm american white oak top.

Legs will be 70 x 70 and rails 90 x 45.

Domino would be a **** of a lot quicker.

Anyone successfully using it on projects of this size?

Cheers, Andrew

 

[gidon]

Chris
Cogged joint? Never heard of that - what is it?
Cheers
Gidon

 

[Paul Chapman]

could I use a "domino" joints for a dining table?

Not really - Dominos are too small. But you could use loose tenons using a router, like this

You really need to make up some sort of jig to cut the mortices in the end of the rails. I made one like this. A bit rough but it worked

Cheers :wink:

Paul

 

[wizer]

I'm quite sure the largest dominos, 4 (or 6) at each joint, would be plenty strong enough and very fast.

 

[fobos8]

doesn't seem any difference between a loose tenon and a domino joint to me.

biggest domino is 10 x 24 x 50mm

is that big enough for a table of this size?

 

[Chris Knight]

Chris
Cogged joint? Never heard of that - what is it?
Cheers
Gidon

Gidon

Like this

 

[Paul Chapman]

doesn't seem any difference between a loose tenon and a domino joint to me.

biggest domino is 10 x 24 x 50mm

is that big enough for a table of this size?

A Domino and a loose tenon are the same but with the largest Domino only 25mm of the Domino would be in each piece. I would say that is too short for the size of table you are making.

Cheers :wink:

Paul

 

[sometimewoodworker]

doesn't seem any difference between a loose tenon and a domino joint to me.

That is because domino joint is a loose tenon

The difference between using a Domino and other ways is in the speed and ease of cutting accurate mortises. Typically less than 60 seconds per accurately cut mortise. While that may seem to be a slight benefit is really a huge difference. I now often use M/T joints because it takes so little time.

biggest domino is 10 x 24 x 50mm

is that big enough for a table of this size?

They are easily big enough :roll: It is just that using most other methods making several exactly aligned mortises is difficult whereas with a Domino it is trivial.

Under are just 2 examples of using multiple dominos in joints
FWIW he is cutting 8 mortises 4 per end of a mitered 50mm x 100mm (2x4) making a 7' x 7' gate

http://web.hypersurf.com/~charlie2/DougGate/DougGate.html
http://web.hypersurf.com/~charlie2/DOMINO/DOMINO_TableOfContent.html[/b]

 

[fobos8]

thanks for the comments about Dominos and Loose tenons.

I'm just not comfortable about spending £300 on oak for a table I want to last for years and years and joining it with a domino.

I think loose tenons would be better cos you could make them bigger than a 10 x 24 x 50mm domino. 25mm in each member isn't much.

I think I'll do tradional mitred and haunched m & t using my router and a couple of jigs. The tenons on the long side of the mitre will be around 55mm long by 60 wide. Thats a huge gluing surface compared to the domino.

I'm sure for smaller lighter tables I'll use my mate's domino - not for this one.

Saw the link of the guy making a 7 x 7 foot gate using a domino. I think this is clueless.

 

[woodbloke]

doesn't seem any difference between a loose tenon and a domino joint to me.

That is because domino joint is a loose tenon

The difference between using a Domino and other ways is in the speed and ease of cutting accurate mortises. Typically less than 60 seconds per accurately cut mortise. While that may seem to be a slight benefit is really a huge difference. I now often use M/T joints because it takes so little time.

biggest domino is 10 x 24 x 50mm

is that big enough for a table of this size?

They are easily big enough :roll: It is just that using most other methods making several exactly aligned mortises is difficult whereas with a Domino it is trivial.

Under are just 2 examples of using multiple dominos in joints
FWIW he is cutting 8 mortises 4 per end of a mitered 50mm x 100mm (2x4) making a 7' x 7' gate

http://web.hypersurf.com/~charlie2/DougGate/DougGate.html
http://web.hypersurf.com/~charlie2/DOMINO/DOMINO_TableOfContent.html[/b]

That mitred joint could be done equally as well with a couple of biscuits :wink: - Rob

 

[Brian Jackson]

Domino and this is they way I do it,copied from a mate who makes hundreds of tables.

http://i3.photobucket.com/albums/y79/ci ... /table.jpg

And as you can imagine,he has to get it right.

 

[gidon]

Chris
Cogged joint? Never heard of that - what is it?
Cheers
Gidon

Gidon

Like this

Thanks Chris!

Cheers

Gidon