POPULARWOODWORKING.COM ■ 25Horizontal Mortiser:
A Furnituremaker’s Best Friend
Last, I can get perfect-fi tting tenons
right off the planer.
Part of why I love slip tenons is
my horizontal mortiser, which makes
it easy to cut matching mortises in
the ends or edges of any workpiece.
See “Horizontal Mortiser” for more
on my mortiser and some good
alternatives.
Mill and Shape the Parts
I begin the design process with a
full-size side view of the chair, which
I draw on a piece of^1 / 4 ". MDF. This
lets me see how the chair will look
and sit, and lets me work out the
main dimensions and angles. Add
to that a few patterns for the curved
parts, plus a plan (top) view, and
you have what you need to start
building. With this article, of course,
you have all of that already, but I
would still consider drawing out the
main views full-scale.
You’ll defi nitely need to make a
template for the curved back legs,
using more of the^1 / 4 " MDF, which
includes the locations of the mortises
for the seat rails and crest rail. I use
that template to lay out the legs on
my lumber with two goals in mind:
minimal grain runout and symmet-
rical grain on the front face of each
leg, especially at the top. I achieve the
latter by fl ipping the template to lay
out each leg.
After cutting out the shapes on the
bandsaw, I carry the line for the top
of the side-rail mortise from the tem-
plate to the workpiece, and around
all four sides. It’ll be my reference
for a number of subsequent steps, so
I don’t want to lose it as I joint and
plane the legs to fi nal thickness.
The bandsawn curves can be
spokeshaved and handplaned to
their fi nal shape, but if you’re making
more than one chair, I recommend
taking the time to make a template
jig for the shaper (see photos 1–5).
You can do the same on a router
table; you’ll just need to take lighter
cuts and be more careful to avoid
tearout. After shaping the back legs,
As my woodworking projects became more complicated, I built my own horizon-
tal mortiser. I recognized back then that using slip tenon-joinery would let me cut
my rails and pieces at clean compound angles on the tablesaw, without having
tenon shoulders to fi t and extra tenon length to account for.
On the mortiser, once I fi t the piece wherever I wanted it to go, I just had to
align the ends of that piece with the front edge of the mortiser table and cut a
mortise. Also, the mortiser cuts mortises just as easily in the ends of parts as it
does in their edges.
As I started doing this sort of joinery, I found that the whole process was much
faster and more precise, even with simple pieces like doors. I’ve never looked
back since then, and I think my success as a furniture maker is due in large part
to having horizontal mortisers in my shop. Some of my chairmaking students
show up as doubters, but most start looking for a horizontal mortiser as soon as
they leave class.
After a while I bought a commercial mortiser called a Stanfi eld, and eventually
became a dealer for the product. When the owner retired, I bought the remaining
stock. I redesigned the machine a couple times, had it manufactured locally, and
sold 50 more over the years.
On the other hand, lots of machines and techniques will deliver good slip-
tenon joinery, including the Multi-Router, PantoRouter, European-style horizontal
mortisers, and mortising attachments that come with some jointers and multipur-
pose machines. With a few jigs, the Festool Domino works well too.
The reason I prefer the Stanfi eld concept is because the piece of wood you’re
working on is right in front of you as you work, letting you see your layout as you
set up the machine, and the cutting action as you mortise. And the wood stays
stationary while the bit moves, which is a signifi cant advantage for large pieces,
like bed rails. I use metal-cutting, solid-microcrystalline end mills for the mortis-
er, since they are just a fraction of the cost of woodworking bits. I’m not pushing
the product, but I’ve still got some to sell. Contact me at terrafi rmadesignnw.com
if you’re interested.