Sunday, June 1, 2008

Mortise & Tenon

There are two beefy mortise and tenon joints (read: lots of room for error, if you're like me) that support the stretcher on the sawbuck table. The mortises are 1.5" (w) x 2" (h) x 1.375" (deep) and the tenons are almost 5" long. I laid out the mortises using a cardboard template to ensure that both would align correctly, then removed the bulk of the wood with a forstner bit chucked into my drill press.

A mortising chisel removes chunks of wood in short order and a paring chisel cleans up the sides of the mortise. I worked from both sides of the leg assembly and checked for square along the way. If you pare from both sides, often a crown is created in the middle of the joint, which is revealed by a square.

To layout the tenon, I used a slicing gauge to incise lines on the end and on all four sides and defined the shoulder with a chisel before roughing out the shape on the band saw.

Then, for two reasons, I used a #50 rasp to work the tenon down to the layout lines:

1) The rasp quickly removes band saw marks and 2) I have never been able to make my Stanley shoulder plane work properly. It's demon-possessed. No, really. That's the only possible explanation.


Anonymous said...

Take that square of yours and check to make sure that the sole of your shoulder plane is actually square to the sides. Yours wouldn't be the first Stanley to be out of square, and that would explain a few things.

Anonymous said...


Demons... I have a feeling *that* is what influences some of my hand tools ;-) . I am in the middle of a program in my shop: Try to use hand tools at least one hour each and every day.

So far, it seems to be helping a little bit. But then, the demons...

Kari Hultman said...

Thanks, Anon. I just checked it and it is a bit out of square (and bumpy, actually), but it only takes a bit to not work well. I'll work on flattening the bottom and see if that makes a difference. I probably should have invested my money more wisely and bought a L-N or Clifton. I have used both of those, belonging to friends, and they work exceptionally well. Thanks!

Kari Hultman said...

Al, good for you! We'll make a handtool lover out of you, yet!

I struggled with handtools until I started taking classes. Some people (me) learn better when someone shows them how to use something properly.

Anonymous said...


The crown or belly in the mortise is probably a result of the use of too wide a chisel.

A narrower mortise chisel will usually produce a squarer cut with less chance of belly.

I do use a wide paring chisel as a final finish but not until the hole is through the board and square.

The square profile of mortise chisels that are properly sharpened, will usually keep the cheeks straight.

I would have drilled one very large hole (if possible), nearly the same size as the mortise to reduce the amount of waste I need to remove.


Kari Hultman said...

Stephen, that's possible about the chisel and I see why you'd suggest that. In my case, however, it's an operator technique. I tend to sneak up on cuts, any cut, so I don't accidentally undercut and remove too much material. This may be a gender thing, I don't know. Many of the female ww I know also tend to work slowly & cautiously.

Yeah, had I a large diameter bit, I would have used it. The largest one I have would have made it difficult to drill two overlapping holes w/o deflection and would have left a good bit of wood, so I chose to use a smaller bit and make more holes. And, with never being in a hurry, the little bit more time it took to remove the waste managed to get me out of doing more yardwork. ; )

Vic Hubbard said...

Your project is looking good. Finally, the photo we've all been waiting for...the sexy chisel shot!
:D I can't believe your partner really lets you use "I've got a project going" to get out of yard work. What's your delivery? I need some pointers there.

Kari Hultman said...

Vic, are you sure you want pointers from me given the last bit of advice I offered you???

Vic Hubbard said...

LOLOL!!! You have a point:D

Unknown said...

I figured why it seems difficult to me, you make look so easy.

Kari Hultman said...

Wyld, things are easier when you work as slowly as I do. : )