Chapter 8 Power Tools 209
Copyright Goodheart-Willcox Co., Inc.
and a uniform surface fi nish. A planer will
keep both sides of a board parallel, but it
will not remove a bend or correct a warp.
Jointers use rotating blades to
straighten and fi nish the edges of lumber
for applications in which boards are fi tted
side by side. See Figure 8-43. Jointers
produce very fl at surfaces, with bends and
warps removed. A jointer can be used to
do most of what a planer does, except that
it is not as effi cient at planing to uniform
thickness. Using the fence on a jointer can
produce an edge at a perfect 90° angle or
produce a precise mitered angle along the
edge of a board.
Planer and Jointer Rules
Follow the power tool safety rules and
observe these rules to safely operate a planer or jointer:
• Do not plane boards with serious splits or loose knots. Planing through
lumber coated with a fi nish can damage the blades.
• Feed lumber so that the blades cut with the grain. Cutting against the
grain causes tearing and splintering of the wood.
• Remove small amounts of material with multiple passes instead of a
large amount with one pass. This better preserves the condition of the
equipment and produces smoother fi nishes.
• Keep your hands and fi ngers away from the rotating blades. Use a
push stick to manipulate smaller pieces.
• Handle boards from the side. Do not stand directly in the line of feed.
• Keep the board in constant contact with the table. If you are using the
fence, the board must also remain in constant contact with the fence.
Grinders and Sanders
Power grinders and sanders are machines that use consumable abrasives
to shape or condition the surfaces of stock materials. Abrasives are hard, sharp
materials used to shape, clean, or fi nish a workpiece. They are termed consumable
because they wear away during use and must be replaced regularly. Grinders
are used primarily with metals, whereas sanders are typically used with
wood materials. These machines may be handheld or stationary.
Grinder and Sander Rules
When using any type of grinder or sander, observe the power tool safety
rules described earlier and these general safety precautions:
• Always operate grinders and sanders in well-ventilated areas.
• Allow the tool to reach operating speed before contacting the work
material.
Fence
Guard
Bed
Depth
adjustment
Base
Goodheart-Willcox Publisher
Figure 8-43. Jointers are similar to planers, but they are
configured to shape and straighten the edges of lumber for
tighter fits during construction.