Popular Woodworking – October 2019

POPULARWOODWORKING.COM ■ 27

12

10 11

10 Use the rail mortises to

lay out the leg mortises. To

create a^3 / 16 " reveal, I extend

my combo square past the

front mortise wall by that

amount.

11 Use the marks from the

leg templates to lay out the

top and bottom of the side-rail

mortises.

12 The back legs lie on their

side, with the fl at area aligned

with the edge of the mortiser

table, and the mortise goes

squarely into the leg.

How I Handle Slip Tenons
At this point I mill tenon stock to fi t
the mortises I’ve cut so far. I like ash
here because it’s stable and inexpen-
sive, with large pores that give the
glue a little more bite. I start each
piece on the jointer and planer, test
the fi t in a mortise, and then move
to the tablesaw and router table to
rip each piece to width and round
the edges before chopping the ten-
ons to a bit under the depth of the
two mating mortises, to give excess
glue a place to go.
After a quick dry-fi t to make sure
everything comes together well, I
always glue the tenons into the rails
fi rst, so I can dry-fi t the chair as it
comes together. I use Titebond III,

and clean up any squeeze-out so the

other mortise will go on easily later.

I’ve got more mortising to do on the

front and back legs, so I leave those

separate for now.

By the way, I always mark the out-

side faces of glued-in tenons to help

me to keep the pieces oriented prop-

erly through the rest of the build.

More Seat Joinery

Now we can go on to mortising the

front seat rail as well as the back one,

which is extra-thick now to accom-

modate its curve. Because all four

legs are vertical in the front view,

the back and front rails enter them

squarely, making the joinery simple.

Note that the mortise in the back rail

is set back^3 / 8 " from the front edge

so you don’t expose the tenon when

cutting the curve.

To locate all of the leg mortis-

es vertically, I simply carry a line

around from the side-rail mortises.

By the way, to keep the side, front,

and back tenons from interfering

with each other inside the legs,

I make the back- and front-rail

mortises a little shorter. Most of the

stresses in a chair occur in the side-

rail joinery, so I want those tenons

to be as long as possible.

Also, I locate the front-rail mortis-

es for the same^3 / 16 " reveal used on

the side rails. And once again, I mill

up the loose tenons I need, and glue

them into the rails only at this point.