Crisp Tenon Shoulders with Your Chisel
Here’s an age-old woodworking tip straight from the workshop of one of the finest period furniture pros out there.
Phil Lowe has been cranking out top-notch pieces for well over 40 years. A graduate and former instructor at Boston’s North Bennett Street School, Phil’s the kind of woodworker you can learn a whole lot from, simply be watching him ply his trade. Case in point: Phil’s method for cutting super-accurate tenon shoulders. Here’s the play-by-play, as I learned during a recent Video Workshop shoot for an upcoming series on building Phil’s Workbench That Works.
Scribe Shoulder Lines from Reference Faces
Before marking out for joinery, Phil first selects an adjacent face and edge of a board that converge to form a dead-square corner. This corner is marked with a pencil and all of the scribe lines he cuts into the workpiece to denote his tenon shoulder are marked with his square’s fence lining up on either of these two surfaces only. This results in a scribe line that wraps around the board, and meets up perfectly.
Next, Phil heads to the tablesaw. He likes to use a dado set to cut his tenons but note: he does not cut right to the scribe line. Rather, he cuts just shy of the line and then finishes by paring with a chisel.
Plenty of folks will wonder to themselves-or in the comments section below-what’s the point? Phil finds that he’s able to pare more accurately and doesn’t have to worry about blowout at all. At the end of the day, most folks will choose to simply cut to their scribe lines but Phil’s technique allows us to break out our beloved chisels and do things a bit more slowly, and deliberately. This technique is essentially a vestige of a bygone era when tenons were always cut by hand. It may be an anachronism, but it’s a technique which-when executed by a pro-is a beauty to behold.
1) Begin by marking out your two reference surfaces with pencil.
2) Next, make your first scribe line, with the square's fence resting against one of these reference surfaces
3) Rotate the workpiece for the next line. Set your knife into the corner of the board, resting in the scribe line you just cut, slide your square up to the knife, and strike the line. Again, make sure you are referencing your square's fence against one of the reference surfaces. Rinse and repeat.
4) Now at the tablesaw, line up your blade (most folks will use a dado set but in this case, I'm using a conventional blade with Chris Becksvoort's speed tenoning technique) just shy of the scribe line (1/32-in. to 1/16-in.) and cut your tenon.
5) Use a chisel to pare down to the scribe line. Slide your chisel's cutting edge up into the line and pare out a small, 1/16-in. section. Continue working on down the line, chopping down to the scribe line along all four faces of your workpiece.
6) Here's what you'll eventually end up with - tenon shoulders cut crisply, exactly to the scribe line.