72 Chapter 4 Hand Tools
Most coping saws provide tension to the
blade through adjustments on the handle. The
blade is changed by loosening the handle three
or four turns and then pressing forward on the
front of the frame. The old blade can then be re-
moved and the new blade inserted into the slots
at each end. Some frames do not have handles
that screw in and out. They rely on the spring
tension of the frame to hold the blade in place. In
this case, apply pressure to the front of the frame
while pushing on the handle. You may need help
inserting the new blade.
In addition to making external curved cuts,
coping saws are used to make internal cuts.
There are several steps to make an internal cut.
First, drill a hole with a large enough diameter
to insert the blade in a waste area of the stock.
Be careful when drilling the hole so that you do
not splinter the back of the stock. Next, remove
the blade from the saw, insert it through the hole,
and reattach the blade to the frame. The internal
cut can then be made.
Keyhole and Compass
Saws
Keyhole saws and compass saws are used
to cut gentle curves or small openings in stock,
Figure 4-33. Start by drilling a hole in the waste
area of the stock; then insert the saw and cut out
the opening. Manufacturers have a variety of
blades that can be used for different materials
and varying radii of curves.
Keyhole and compass saws are very similar
in appearance. The keyhole saw is a bit smaller
than the compass saw. The keyhole saw, as the
name implies, was originally used for cutting
lockset openings in doors. The compass saw
usually has 7–10 teeth per inch, while the key-
hole saw has 12–14 teeth per inch.
Figure 4-31. You can construct your own V-block to
use with the coping saw
Figure 4-32. A regular shop vise is bett er than a
clamp because it will hold the stock more fi rmly.
Figure 4-33. Keyhole and compass saws are used to
cut small openings.
Goodheart-Willcox Publisher
Goodheart-Willcox Publisher
Goodheart-Willcox Publisher