Is there a way to cut mortises cross-grain?

[Jared Walters]

I tried to do it on a project I was working on and I did not have a good time. My very sharp chisel could cleanly cut into the into mortise, but I couldn't get the waste to clear from the sides. It would just pull and splinter and crack.

Is there a technique to it or is this another case of a novice learning an important lesson through error?

[Jim Koepke]

It may be dependent on the wood you were using.

After all, a dado is a type of cross grain mortise.

The sides are usually saw cut or knifed.

jtk

[David Weaver]

Drill and pare.

[Daniel Rode]

I'm no expert but I've worked some of these like a short wide mortise. Chopping perpendicular to the grain to make 2" mortise that's 1/4" long.

[Mike Henderson]

Be careful with cross grain mortise and tenon. The end grain does not glue well, even to long grain. You'd do better to make two mortise and tenons in the piece and go with the grain. You want long grain to long grain on the face of the mortise and tenon.

Mike

[Steve Baumgartner]

+1 On the divider below drawers it is very common to make a double mortise & tenon for exactly this reason.

[lowell holmes]

I use slip tenons in such a case. It works.

[Jim Matthews]

It may be dependent on the wood you were using. jtk

+1 on this.

What species are you mortising?

[Rob Luter]

I did it on this spalted maple stool. Drill and pare is the key. Make sure your chisels are razor sharp and take light cuts.

https://farm6.staticflickr.com/5486/11154548885_5061b7815b_b.jpg

[Kees Heiden]

And make sure you create a knifewal in the sides first where you would get splintering otherwise. It's a lot more work then a normal mortise, because you have to tend to the sidewalls too and because the waste doesn't come out so easilly.

[Steve Baumgartner]

Just an observation: on that table top gravity and wedges hold the tenons into the mortise, the strength of the glue is largely irrelevant.


I did it on this spalted maple stool. Drill and pare is the key. Make sure your chisels are razor sharp and take light cuts.

https://farm6.staticflickr.com/5486/11154548885_5061b7815b_b.jpg

[Daniel Rode]

Perhaps I'm nit picking but I would not use a wedged tenon parallel to the grain. The wedge, AFAIK, should be perpendicular to the grain to avoid potentially splitting the mortised piece.

[lowell holmes]

I use slip tenons in such a case. It works.

I miss read the question.

When I built the bench that Rob showed, I chopped the mortises with a chisel. Of course I was using pine. Some more brittle woods might present a problem.
In such a case, I would drill holes and clean up the edges with chisels.

[Rob Luter]

Just an observation: on that table top gravity and wedges hold the tenons into the mortise, the strength of the glue is largely irrelevant.

I think the wedges are more effective than the gravity, but correct on both counts. No glue at all used on this stool except for the dowels that hold the side gussets in their mortises. It's rock solid. I've used this technique on a couple other projects too, including the hall table below. The lower shelf is mortised into the ends. I used some oak wedges there, and they pretty much just disappeared once I applied the finish.

Wedged or pinned tenons have kind of become my MO. I still use glue where it makes sense, but I like the belt and suspenders approach in addition to the aesthetic.

https://farm3.staticflickr.com/2557/4081431072_70549c4dd3_b.jpg

[Jim Koepke]

Jared,

As I was working on a tea cabinet for the LOML, this thread came to mind.

This is one way that works for me.

First the area is marked out. I set the width of the dado/mortise to a chisel. Then a wide chisel is used to deepen the scribe lines:

300782

Do this before cutting the ends of the dado/mortise with the grain to avoid splitting. For this shallow dado the deepening of the scribe lines had to be repeated three or four times before reaching the desired depth. For a through mortise one would want to carefully mark from both sides and cut the mortise from both sides.

The wedging action of the chisel's bevel will widen the dado/mortise a hair.

The marked lines should be just a hair wider apart than the chisel used to pare out the waste in order to avoid tearing out the top surface when removing the waste.

300783

If material is cut below the scribed lines you get this:

300784

Hope this helps.

jtk

[Frederick Skelly]

I did it on this spalted maple stool. Drill and pare is the key. Make sure your chisels are razor sharp and take light cuts.

https://farm6.staticflickr.com/5486/11154548885_5061b7815b_b.jpg

Ive made this exact stool from pine. Plan came from FWW, IIRC. That stool is rock solid.

Jared, if this sort of thing is what youre trying to do, heres how the FWW article instructed readers to do it. You cut the mortise with the grain, using the widest chisel you have. Move down the long side, cutting with the grain toward the center. The turn the board and cut down the other (long) side toward the center. When you get half way through the board's thickness, turn it over and repeat the same process from the back side. The process is slow and tedious, but I was able to make nice mortises. (First time I ever tried it. If I could succeed, you probably can too.)

As someone else said, you can shorten the process by using your drillpress to hog out most of the waste.

Good luck!
Fred

[Jeff Zens]

An easy way to create mortises (either with or across the grain) is to fabricate a template for use with a router and a template guide (sometimes called a rub collar). Use either a straight bit or an upcut spiral bit to remove the waste. If you want square corners you'll have a bit of cleanup with a chisel and mallet, or you can simply round off the corners of the tenon with a rasp and then a file. This technique is the basis for floating tenons, as well.

[Daniel Rode]

While that will work -- and I've done mortises this way -- it's an hour solution to a 5 minute problem. By the time I make the template, set up the router, maybe run a test piece, I could have been done chopping them by hand. A router and template is nice for production work, but it's more work if you're just doing a a few.

Drilling out the waste can be helpful sometimes.


An easy way to create mortises (either with or across the grain) is to fabricate a template for use with a router and a template guide (sometimes called a rub collar). Use either a straight bit or an upcut spiral bit to remove the waste. If you want square corners you'll have a bit of cleanup with a chisel and mallet, or you can simply round off the corners of the tenon with a rasp and then a file. This technique is the basis for floating tenons, as well.