Chisel slot on
left
Move workpiece this
direction
CAUTION: Do not have the chisel slot against the blind end of the mor-
tise, as the chips will not be able to clear the chisel. This can cause over-
heating and possible breakage of chisel or bit.
When cutting deep mortises, make the cut in several stages of approxima-
tely 1" each, to allow chips to clear. To prevent breakout at the back of the
workpiece when cutting through mortises, use a piece of scrap material
under the workpiece as support.
MAINTENANCE
The Mortiser requires only minor maintenance, such as cleaning and lubri-
cation and routine adjustment and sharpening of the chisel and bit.
Dust the machine down after each use and, as necessary, use light applica-
tions of oil or grease to lubricate linkages, moving parts, etc.
SHARPENING CHISEL & BIT
The chisel and bit should be kept sharp for best performance. Blunt edges
will give inaccurate mortises and can lead to overheating and breakage to
chisel or bit. If chisel and bit are badly worn and become difficult to shar-
pen, they should be replaced.
1. Sharpen the bit by using a small, smooth file, following the original
shape of the bit. File the inside edge of the spur, the sides of the brad
point, and the cutting edge inwards toward the flute of the bit. See
Figure 7.
File inner edge of
spur
Chisel slot on
right
Mo ve workpiece this
direction
Figure 6
File sides of
brad point
File cutting edge
Figure 7
Do not file the outside edge of the spur as this will affect the diameter of
the bit.
2. Sharpen the chisel with a mortise chisel cutter with the correct size
pilot. (Pilot size will differ depending on the size of your chisel). Two
or three turns of the cutter in a carpenter's brace chuck should be
enough to sharpen the chisel, as shown in Figure 8.
Brace chuck
3. Use a small, triangular, smooth file to relieve the inner corners of the
chisel. See Figure 9.
Remove any burrs from the outside of the chisel with a fine oilstone.
31
Cutter
Pilot
Chisel
Hold chisel in
soft-faced vise
jaws
Figure 8
Lime
Burin
Figure 9