Is there a good way to chop mortises squarely?

[Winton Applegate]

Ha, ha I don't have anything constructive to add except to say relax and enjoy your self.

I would encourage you to watch more Roy Underhill Woodwright episodes . . . his rustic results can make you feel pretty good about the fit and finish of your joints.

In the same breath it is probably best TO AVOID watching Frank Klausz cut mortice and tenon joints . . . could cause you to lean toward an enthusiastic bout of hara-kiri.

[Jim Matthews]

I think you just discovered the truth behind the myth Derek. He isn't actually doing any woodworking himself. There are some hired professionals in the dungeon behind the curtain who do all the work and then Derek displays the items in the staged shop, makes pictures and writes about them.

I knew it!

[Derek Cohen]

Do you keep a picture of a basement behind a curtain, that looks like a dungeon?

Photoshop is great!

Regards from Perth

Derek

[Adam Cruea]

The picture tells the story ...



I may also stand a 12" square alongside the chisel. With these two visual aids you won't go wrong. Within a short time you will develop a sense of vertical.

Tutorial: http://www.inthewoodshop.com/Furnitu...gByChisel.html

Regards from Perth

Derek

This is what I do, except I use a K-Body Bessey (sometimes two if the piece getting mortised is long).

Also, make sure the edge doing the cutting is perpendicular to the sides (if you have the type of mortise chisel).

By the way, it slightly bears mentioning, if you're a hulk and/or going through particularly dense wood, try to do the chopping over a bench leg. While it's pretty negligible, you'll get a more solid whack out of each swing, and you'll transfer the energy directly down to the cement pad your bench probably sits on.

Not hugely important, but hey. . .

[Derek Cohen]

By the way, it slightly bears mentioning, if you're a hulk and/or going through particularly dense wood, try to do the chopping over a bench leg. While it's pretty negligible, you'll get a more solid whack out of each swing, and you'll transfer the energy directly down to the cement pad your bench probably sits on.

Not hugely important, but hey. . .

Adam, that is important .. and even more so if the bench top is not the thickest - a thinner top may flex.

For those that did not register this from the photo - the chisel is positioned at the centre of the chop of a leg vise ...

Regards from Perth

Derek

[Tom M King]

Have a helper do the holding, that can make adjustments to counter your out of vertical mistakes, especially with $27 bd. ft. boards 20 feet long.

[david charlesworth]

Of course the mortices don't have to be perfect.

If they are glued and clamped, (or pegged), the shoulders will pull up tight.

This puts a slight bend on the tennon, but the glue or pegs will hold a pretty good position. At least this is what happens on furniture scale work.

best wishes,
David

[ken hatch]

Of course the mortices don't have to be perfect.

If they are glued and clamped, (or pegged), the shoulders will pull up tight.

This puts a slight bend on the tennon, but the glue or pegs will hold a pretty good position. At least this is what happens on furniture scale work.

best wishes,
David

Yep, pretty much.....It's one of the reasons I love draw boring, if the shoulders are good the M/T joint will be good. Not an excuse to be sloppy but a pin or two can make up for a lot of errors.

ken

[Michael Ray Smith]

Not if you use a hand-powered drill press. I have an old Millers Falls -- or maybe its Goodell-Pratt. Don't recall at the moment. Not nearly as precise as modern drill presses -- much more runout. But good enough for this purpose. It seems to reduce the wobble some if you use a forstner bit, at least if you have the wood clamped down tightly.

[Michael Ray Smith]

I have the same problem, and I'm still working on that "practice, practice, practice" part. Clamping a straight board or something similar along the edge of the mortise, as others suggested, is the most helpful thing I've tried. I also drill out a lot of the waste, but I use a bit that's smaller than the width of the mortise, but maybe I should try more often with a bit that the same width as the mortise and the side of the drill hole to get the side of the mortise straight. It's also helpful if I sneak up on the edge of the mortise by slicing away the last few millimeters with a paring chisel, a little at a time, rather than just chopping away all the way to the line with a mortise chisel. But that's just me. You mileage may vary.

[Brian Holcombe]

I knew it!

And the sacrificial thumb to help legitimize the the story

[Winton Applegate]

I am not a big old dog when it comes to M&T but pre drilling the mortises . . .
for me
is a night mare. Paring out the middle the chisel twists unexpectedly one way or other driven by the interaction of the bevel on the sides of the holes. Paring the sides of the mortise with a wide chisel gets more out of hand than just chopping out from scratch (no drilling at all) with a mortising chisel.

My mileage is a flat tire with no spare by the side of the road.

PS: I love my nice floor model drill press and Forstner bits though. I can happily play with those all day.

Oops . . . that was not very Neander of me was it.

[Prashun Patel]

Always looking for a guide and short cut, I've found that the key to straight mortises is indeed tedious practice. My mortises too started out v-ish. After a few, my eyes were able to anticipate what the tenons were going to say about the mortises. My problem is mortising is like drywalling. I get good at it by the last one of the job. By the time the next job starts, I'm rusty.

A guide actually slows me down in mortising.

Also, try a wider chisel. It's easy to set a wider chisel once than a 1/4" chisel vertical many times.