Mortise and tenons

[Palletmangler]

Does anybody have any recommendations for the size of mortise and tenons? Im sure in school I was taught to stick to thirds i.e. if I had a leg three inches wide and a rail to attach of say 2x3, then I'd mark out the middle third and make the tenon on the rail to suit.

I can't remember though, if there were any rules to the depth and length.

Anyone got any rules, preferences, philosophies? I just want to make sure when I do them they arent going to snap off!

 

[RobinBHM]

It depends largely on use and whether you are using a morticer with a set chisel size.

If you are making somethjng with a rebate or groove then mortice size is determined by the space available and whether the mortice in rebate or not.

Doors and window frames are often just made with a half inch chisel.

 

[blackrodd]

As Robin says depends what you are making windows and doors need to be strong, so a through wedged joint is usually
used.
Framing and lighter work can use short, or stub tenons, usually glued and pegged.
What are you making! would be helpful to help you.
Regards Rodders

 

[Palletmangler]

Well at the moment I'm thinking about a kind of table with an open end to go in my larder cupboard.

One side will be open so it can go in up against the walls in one corner and the fridge slide inside it. Then on top of the table will go the tumble dryer.

I did some hand chiselled mortises at the weekend but they were quite rough so I thought I'd try the plunge router technique. Problem was, I'd left the cutter in from the last time I'd used it and it is well stuck! It was the right size bit for my width but I'm still quite new to these things and I'd set it too far down the collet. I could only get a cut 3/4 inch deep! And now I can't get the thing out to set it a bit longer!

So the mortises with the router are about 20mm deep, 12mm wide and 50mm long. The wood I'm using is some CLS type timber 70x45mm dimensions. The footprint of the table is 550mm x 600mm.

Obviously I could cut them a bit deeper again by hand but if that sounds to anyone like a deep enough mortise, long enough tenon to hold it together I'd rather just do the rest with the router and get the table up and standing!

 

[Steve Maskery]

That's nowhere near deep enough. For table legs, you can't do both as through tenons, so usually both are blind, but offset towards the outside to make them as long as possible. Table legs get subject to a lot of abuse when dragged across a floor, which is why they usually have rails as well as aprons.

If your aprons are 3/4" or so, 1/3 would be 1/4", which I think is a tad thin. In such a case, because the leg is so much thicker, I would cut mine at 3/8, or1/2" if the leg is chunky. That would still leave you a 1/8" shoulder.

PS Do you have a drill press? You can drill out most of the waste first. It makes the job quicker and gives you a good start on accuracy.

 

[custard]

That's nowhere near deep enough.

+1

Getting the tenons right is the best route, but if a design calls for particularly skinny or through tapered legs, then you can recover a bit of tenon strength with a haunch and/or a corner bracket like this,

Good luck!

 

[Palletmangler]

Hmm seems I have a bit more thinking to do. Unfortunately no drill press yet, just mallet n chisel or drilling it a bit by hand and forming the insides with the chisel again.

Its a good thing I asked though or i might have found my tumble dryer on its face one day!

Many thanks for the help peeps

 

[RobinBHM]

I'd buy a 1/2" x 50mm long worktop router bit for that -they are freely available and cheap generally.

that is once you've managed to persuade your cutter to come out of the collet! -Im sure you know collets need double unlocking to come free.

Maybe a bit of rust has stopped the cutter releasing?

 

[Steve Maskery]

PM, what plunge have you got on your router?

 

[Palletmangler]

Its a bosch pof1200. Specs say a depth of 55mm but I don't think I've ever come close to that! I've had it for nearly two years and not used it very much so I'm not very familiar with how it can be best used, just rounded over some things and made some channels in pieces like a photo frame. I tend to go to use it, have to relearn how it works and then run out of time and have to put it away again!

 

[Homerjh]

same here palletmanager!

 

[Steve Maskery]

I've no wish to rain on your parade, but I think you would be better off getting a a tumble-dryer kit which allows you to hang the TD on the wall. You can then practise your woodworking skills on something less critical.
Really.

 

[blackrodd]

As Steve says, you ought to practice on something easier with mortice and tenons.
I suggest you get some plans of a small table that would look nice wiv a plant on, you would be able to experiment on all the cutting, joints and finishing, and progress to the more involved stuff later.
There are free plans and with a cutting list and some text, you can follow all the techniques involved,
You tube is very good for helpful with tips, how to's etc
Its very easy to get disheartened by just going a little to complicated when starting out.
Something like this, in the link, below,

https://www.google.co.uk/search?q=free+ ... AF0QsAQIJQ

HTH Regards Rodders