Cocked mortises -- fixable?

[Tom Henderson2]

I'm enjoying my first project with hand-cut M&T joints, the Stickley plant stand that Woodworking mag published a few years ago.

In spite of my best efforts, some of the mortises are not square into the material; they lean a bit to the side. Not a lot, but enough that one side of the joint is opened up a little when the parts are assembled.

And things won't be square when it is all put together.

Is there a way to resolve this without major surgery or scrapping the legs and starting over?

The first few tenons are the worst; things got better as I got some experience.

Thanks in advance!

-Tom in SoCal

[Zach Dillinger]

Are they through-mortises? If not, glue in a plug and recut. If they are all the way through the leg, honestly, I'd probably just start over.

[Russell Sansom]

Tom,
There's nothing wrong with 1) paring down the the side of the mortise that slants in and 2) shimming then paring the side that slants out. Glue in a generous, tightly-fitting shim. It's a quick and easy fix. It will have every bit of the original physical integrity and nothing will show. If goes all the way through, this shouldn't have happened ( because you should have carefully marked the exit side and chopped half way from that side ), but, depending on the appearance you're willing to settle for, you can still shim it neatly and the repair should be fairly unobtrusive.

[Jim Matthews]

+1 on squaring up the mortise, and shimming the tenon.

The joint won't be able to distinguish between the bonds - it will be just as solid.
FYI - I like bridle joints at the top of legs, they're easier to handle, and plenty strong.

Pictures of your problem, and the fix would be instructive for us mere mortals attending.

[Sean Hughto]

You can adjust the shoulders or bury the shoulders.

[Tom Henderson2]

Thanks everyone; I appreciate the suggestions. I'll try to work up some photos to better illustrate the problem, and hopefully the solution too.

-Tom in SoCal.

[Jim Koepke]

Mistakes are a fact of life.

How they are dealt with is the difference between a good craftsperson and a great craftsperson.

It may be possible to tilt the tenon to match the mortise. This might require adding some material to the tenon.

One way to hide gaps, joint lines and such is to open them up. Rounding the edges on the showing shoulder's gap will make it look like it was meant to be that way. Give it a little Greene and Greene treatment. Turn a mistake into something people want to run their fingers over and purr. You'll just have to do it with all the joints to pull it off.

jtk

[Matt Ranum]

I'm working on a cabinet as we discuss this that I had the same problem with. I squared up the mortise then glued a piece to my tenon, then just milled it back down to fit. I was really perplexed for a while until I just sat back, thought, and simplified the problem in my head. I have to do that sometimes before that goofy lightbulb in my head will go on. :p

[Jim Matthews]

You can adjust the shoulders or bury the shoulders.

Do you mean creating a recess in the mortised section so that the tenon shoulders are covered?

[Jessica Pierce-LaRose]

Depending on the design, proper draw-boring can make up for ridiculously ill-fitting mortises - although it wouldn't fix a skewed mortise, it can make a loose one (from trimming the tenon until things fit square) plenty strong.

I'd still fix the mortise or tenon and shim the tenon as discussed, first, however.

[Sean Hughto]

If you are asking what I mean by bury, I mean that you can knife around the outside of the tenon shoulders on the mortise member and create a shallow recess with a chisel or router plane. You can even take more out in some places than others so that the tops of the shoulders sit flush. Beware that once you start futzing like this you will have to futz with other members as the adjustments to one joint will require adjustments to others.

[Jim Matthews]

That's clever, right there.

Yet another reason why my time in the Creek is valuable.
(Not that any of my joints suffer from gaps, or alignment problems - mind you.)

The only attempt I made at draw-boring fractured two of four legs, even with a mild 1/64" offset.
This method seems practical enough that even I could manage a clean reveal at the shoulder...

Thanks, Sean.

[Bryan Schwerer]

Hi Tom,

BTW, I love that plant stand and have wanted to try it for a while. It looks like the others have given you some advise to fix the issue. I will let you know how I got better at mortising straight. I wish i could remember where I learned this to credit it. It also works with boring holes. First, I clamped my piece to the bench with a hold fast, parallel to the front of the bench. Clamp it pretty close to the edge of the bench. Then at the end of the bench I will be facing, I clamped a bar clamp upside down (bar facing up) on the bench, lined up with the mortise. When chopping out the mortise, I sight down the line, making sure the top of the chisel is lined up with the bar. That way you get a good reference for square. Pretty soon, you just start having that feel for square naturally and you won't need the clamp.