Jointing the Stone

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Basically, a mortice is a hole. With hand tools, you can chop it out with mortice chisels or drill out the waste and pare to the lines. But we use a morticing machine.


This is an excerpt from “The Intelligent Hand” by David Binnington Savage.

Joinery – that’s what this is about. Joints that hold components together. In this case, versions of one joint, the mortice and tenon. There are on this bench frame three different versions: stub mortices and tenons; through-wedged mortices and tenons; and through dry-tusk-wedged mortices and tenons. So that you can take this structure apart to move it, the tusk wedges are just friction fit, but the bench is solid as a rock when assembled.

To gain strength, we use wedges in two of the three joints. In the knockdown joint, the top of the mortice is angled – a wedge is driven in above it to hold the structure. But this is getting too complex too soon – let’s look at the simple through-wedged mortice-and-tenon joint.

Basically, a mortice is a hole. With hand tools, you can chop it out with mortice chisels or drill out the waste and pare to the lines. But we use a morticing machine, which saves lots of work. This is basically a drill bit that cuts slightly ahead of a square cutter that chops out the corners.

First let’s get into marking-out mode. This diagram gives you the idea. Mark distinctly both the component position and the mortice position. Mark the mortice with a mortice gauge, with the knives set 30mm apart. As always, mark from the face side of each component.

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This is the type of drawing that I like to see every student make before making a joint – it helps one to think about what is being done, and to think about the mechanics of this joint. This is not just a peg in a hole with glue; it’s a mechanically effective joint that would hold up without any glue. The two small wedges turn the tenon into a dovetail, splayed wider at the outside than the inside. It’s as tough as old boots.

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The completed mortices.

First make the hole (the mortice) then the plug (the tenon) to fill it. Our morticer cuts pretty cleanly; I like and use machines that save me time and do a better job than I could. Chopping out a mortice by hand is nice and sweaty work – and some of you will be happy doing it.

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The tenon gets marked out with the same mortice gauge setup (30mm, marked from the face edge). We use a setup on the band saw to cut those tenon cheeks to exactly the right size. Because this joint gets cut a lot, a dedicated setup for it makes good sense.

Have a careful look at the drawing above right, noting the stop and spacer at the bottom of the page. This stop is simply a block of wood cramped to the band saw table. Next to it is 31.5mm-wide spacer against the fence. The fence has a stop at the end to prevent you from going too deep past the shoulders. The idea is this: After the first cut, you need to move the fence 31.5mm to make the second cut and get a 30mm tenon. Try it out with some scrap. Cut one tenon cheek, take the spacer out, move the fence then cut the second shoulder. Does this give you the tenon you want? If not, cut a new spacer, thicker or thinner, as needed.

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Band saw setup for cutting tenons, plan view.

Make sure your blade is good and sharp and that you run slowly into the blade. Chunka, chunka, chunka….

We cut the tenon shoulders at the table saw. The blade height will be the same for all; the shoulder position will be measured for all and a stop set up probably off the end length. Tenon lengths will be different for the different kinds of joints.

Meghan Bates

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7 Responses to Jointing the Stone

  1. hugo says:

    Thank you very much! Question: There use to be some ecxerpt from your books. But some of them don’t, like Shaker Inspirition. Why? It helped me a lot to make my decision, mostly as a beginner.
    Bravo for all your good work!

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  2. Al says:

    Get Shaker Inspiration. Lousy title (in terms of all the book covers) but correct title for the book ( I would have called it that too )Never have a read an author that I believe thinks exactly like me until that book. Other LAP books are awesome, Shaker distills a lifetime of info into just one book, and in a way that if it were more info, you would get lost, but if it were less, you’d never get it. Perfect. The snippet on wood movement it worth it alone, and its just a page or so. Excellent book, just Excellent. Will be getting His other books now.

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  3. dpcrow says:

    Great passage. Thank you for sharing and publishing his work. Just curious. Am I missing the part where he describes how to get the mortice wider at one end than the other.? Is that just chiseled out?

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    • Jeff Simpson says:

      I was wondering the same thing. I’ve never used a hollow chisel mortiser but the ones I’ve looked at have adjustable tables like a drill press or band saw.

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    • toolnut says:

      My guess is it is chiseled out. It would be quicker as you are really just paring it wider at one end and in the case above you are only going about halfway into the joint.. The mortiser is also possible but requires a new setup which takes time and unless your bit is super sharp and your mortiser is heavy duty and your piece is clamped down properly you will get some deflection and spend even more time trying to minimize that than just using a chisel. Just my two cents.

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