Untitled - Wood Tools

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OPEN MORTISE&TENON
Strength, durabiliry and ease of assembly -
three reasons
for using an open mortise and tenon joint to
assemble the mid-caps of the porch posts.
Open Mortise & Tenon - Also known as a "slip"
joint, it has an open-ended mortise on one piece that
accepts a tenon on the mating piece (Photo,below).Here
again, these interlocking parts and the large glue suface
they create form a strong, durablejoint.
Layout - The first step in making an
t
Y.nl
open lnortise and tenon is to lay out
the joint.The mortise is laid
out on one end of
each piece,
and
the tenon on the other. This goes quickly because the
layout for the mortise is exactly the same as it is for the
tenon. I divide the thickness of the workpiece into thirds
and use a combination square to lay out the Lines (Fig. 1).
tcstering
ftlortises
It's best to cut the mortises first. This way, it's easier to
nuke the tenons fit the mortises than vice vena.These mortises
are fairly deep (21/a").So in order to make a safe, controlled
cut, I use the band saw to cut both para of the joint.
Fence Setup - For accuracy, you'll need to set up
a fence.The location of this fence determines the width
of the mortise.The idea here is to position the fence so
the blade will cut to the inside of the layout bne (Fig. j).
< Interlocking ports ond
o lorge glue surfoce moke
the open mortise ond lenon
ioint o solid choice for midcops.
Plus, these two L-shoped ossemblies
wrop right oround o porch post iust like
o collor, so ossembly is o snop.
A A bond sow provides o controlled woy to cut the
mortise. Here, the fence delermines the width of the
mortise, while o stop block deiermines its depfh.
A Loy out the mortise ond tenon I Set the bond sow fence, ond
using o combinotion squore. then use one of the midcop pieces
Divide the thickness into thirds. to set the locotion of o stop block.
48
A Cut both sides of the morlise, flipping the piece
between cuts. Then bock off the fence, ond remove
the middle woste section os shown obove.
woRKBENcH fl.JuNa 2004