My ideas would be to choose naturally dried timbers, as this is the underpinning recipe for a good bench…I doubt knotty pine but whatever it is…I’d use draw-bore or tusk-tenon and wedge joinery. The leg braces used in the examples shown add serious rigidity to benches (which to me seem a plank short in width) and as I reflect on it whilst writing………I wouldn’t use glue. Older benches were commonly braced just under the bench and towards he foot of the leg…often with a central brace as well and a shelf built across the lot.

If the bench can be fixed to the wall then the legs can predominantly do the work legs are intended to do….ensure vertical resistance. As that is rare you get less problems if the bench moves than if the joints flex. If you want to fix the bench it should be fixed at bench height and preferably at both ends…admitting that this might reduce some access to those ends.

Another comment, if you want to sight for out of true using a tri-square, or square…after checking itself for “true”….don’t do it as shown. You can see some light, if out of true, but you should be looking straight along the timber at contact level to see the ‘out of true’ or if obstructed you can use feeler gauges. As shown you have parallax error.The square itself should be no more than a couple of millimetres wide (say 1/16th inch’ish ) or you can have error introduced.

A square may not show you uneven surface along the timber..for that us a good long spirit level tipped at 45 degrees to narrow the edge or work it across the timber using feeler gauges as you go.

When mortising timber make sure you turn the leg around to find the grain so as to to cut the tenon in the correct direction of it.

One thing about the traditional techniques still more commonly used in Europe than expediency neurotic America is that they are a very fine piece of sturdy joinery and adjustable. I was actually quite surprised to see the bracing for the roof overhang of some 6 feet I asked a builder to do to my old place in France when rebuilding the roof was draw-bored and wedged.It does the heart good and I think even non-woodworking types could feel that pleasure.

On balance I wouldn’t glue…the bench can be tightened if ever it needs to be with tusk and wedge and if well mortised and braced will take the working on it with little complaint. I’d rather have a pair of wood face, wooden screw vyces than dogs too for planing and use the dogs only to steady when chiseling a mortise or tenon.Voila

-Steve

-Steve

“Use the Schwarz, Luke! Use the Schwarz!”