Hand tool stock prep

[Mark Rainey]

From a sawmill board we need a flat face, then a straight edge. We can then square the ends with a try square for length. For mortise & tenon construction is there really any need to get the edge exactly square to the face?

[Zach Dillinger]

It doesn't absolutely have to be but it makes it a ton easier to get a square frame. I'm a very lazy stock prepper and even I will put a square edge on. It doesn't take much more time, if any, and it saves a bunch of hassle down the road.

[Warren Mickley]

From a sawmill board we need a flat face, then a straight edge. We can then square the ends with a try square for length. For mortise & tenon construction is there really any need to get the edge exactly square to the face?

For a rail that has tenons, the critical length is the shoulder length, whether for through tenons or hidden. For through tenons we typically make the tenons slightly long and plane flush after assembly. Since the tenon ends get marked with a mortising gauge, it is nice to have a reasonably square end, but not critical. For a stile, we typically leave the ends long until after mortising so that the mortise does not break out at the end.

The edges of a piece to be mortised should be square so the piece will sit flat on the bench and make the mortising more accurate. If one cannot make an edge square in a trivial amount of time, it is probably good to practice.

[Mark Rainey]

Thanks Zach & Warren. Good point on getting the piece to sit flat while mortising Warren.

[Bill McDermott]

Mark, As you suggest, there are certainly ways to shortcut some of the labor. Personally, I only do that on jigs and temporary things. But you can often leave surfaces rough or intentionally short where they are unseen and not structural. Undercutting a mortice tenon or leaving the hidden shoulder intentionally a wee bit short are examples. Working that way can make it appear that you are "getting the edge exactly square to the face" with less effort and time. I would add that things pull together nice and square when the joints are carefully laid out and cut, but components get wonky fast if joints are sloppy. Those minor shortcuts can get amplified into ugly gaps and twists when assembling the larger piece. Those M&T shoulder cuts deserve careful attention. If it needs to be really neat; marking out with a knife, sawing close and paring to the knife line works most reliably and efficiently for me.

[Phil Mueller]

If the end of the board is square, you can use it as the guide for your marking gauge to mark the shoulder line. If not, you need to scribe the shoulder line around the board with a square after careful measurement of the distance between the shoulder lines (going off the reference face and edge). Both ways work fine, but I will typically square the end...just seems easier overall. Usually only takes a few passes on a shooting board. The shooting board step also ensures opposing aprons (or whatever) are exactly the same length.

[Jim Koepke]

In the same way "sharp cures many problems," having properly squared stock will help to eliminate gaps, twisted panels and other problems.

jtk

[Steve Kaminska]

After cutting many crooked joints, I started marking my joinery (lightly, in pencil) before I square the board. This helps me determine which faces must be square to one another to produce a decent joint. Planing the board erases those rough layout lines, and usually ensures that I mark the joinery from the wrong faces.

[Luke Dupont]

Also consider your method of marking and constructing. For example, you can cut good dovetails even if the ends of the boards are not perfectly square by marking them with a knife and try square and working out from the baseline, but if you run a marking / cutting gauge off of the end of such a board, even slight angulations will affect your completed joint.

So, while one person may claim X being square is necessary for Y, it depends largely on the method of laying out and cutting Y as to whether that is true or not. I try to mark things out in ways that require as few perfectly flat / square / cut to length faces as possible, because each new edge I register against, or measurement I make, if not perfect, can introduce error. Why mark from two faces and four edges if you can make all of your marks from one edge and one face? (Transfering those marks, of course, to other faces, but keeping the same primary face / edge as your primary registry faces)

For tennons, if I am understanding the question correctly, the straightness of the tennon depends primarily on how vertically you hold your chisel when chopping the mortise. The shoulders of the tennon don't matter if it is of sufficient length, but there will be gaps which appear if the face of the mortise is not square, and paring the shoulder to rid those gaps will make the overall piece slightly shorter than you may have planned -- which isn't a problem if you left your piece slightly long as a precaution. Remembering what errors are in what pieces and what orientation your joints are cut and might be affected, though, may be an error prone process.

[Dom Campbell]

This also depends on the scale of the work you are thinking of, to an extent.

If using gauges to layout then as others have mentioned, having everything square makes sense.

But there are ways around this, particularly on larger work - which is to use centerline layout, as often used in timber framing, to lay everything out. As you are referencing off the centerline, then as long as everything is square to that, then you’re all good.

This video will show that you can do perfectly square work, on stock that is decidedly not square: