Learn how to use a circular saw safely and effectively. These pro tips and techniques will help you build everything from a few shelves to a whole house faster and better.
By the DIY experts of The Family Handyman Magazine:September 2008
Setting the blade too deep causes a
few problems. First, it's more dangerous
than a correctly set blade because
more blade is exposed while cutting.
In addition, the saw is more likely to
bind and kick back if the blade is too
deep. Safety issues aside, blades cut
more efficiently when properly set.
Determine the blade depth by unplugging the saw
and holding it alongside your board with the blade
guard retracted. Then loosen the depth-adjusting
lever or knob and pivot the saw's base until the blade
extends about 1/4 to 1/2 in. below the board. Tighten
the lever or knob and you're ready to saw.
Always make sure the end of the board you're cutting is free
to fall or move away. For rough cuts in framing lumber, let
the cut end fall. Be aware, though, that the falling piece can
take a sliver of wood with it as the cut nears completion. To
avoid this splintering when you're cutting boards for nicer
projects, support the board continuously. But don't clamp,
hold or otherwise restrict the cutoff piece.
Crosscutting plywood without supporting it across its
entire length can cause the saw to bind or the plywood
veneer to tear or splinter as the cutoff piece drops. If you're
using sawhorses, simply span them with a pair of 2x4s.
This will provide the support needed.
It's sort of like cutting off the tree limb you're standing
on—a guaranteed disaster. The reason is that as
the cut nears completion, the board bows downward,
which pinches the blade in the cut and causes the
saw and/or board to buck. This is dangerous and usually
makes a mess of the board, too.
In most cases, a table saw is a better choice for ripping lumber than a
circular saw. But if you don't have a table saw handy, and the rip cut
doesn't have to be precise, then a circular saw works fine. The trick is to
hold the board in place while you rip it. Unless the board you're ripping
is very wide, clamps will get in the way. So a good alternative to clamping
is to tack the board down to your sawhorses. We let the nails protrude
here because they don't interfere with the saw bed. But you can drive the
nails (or screws) flush and still easily pull the board off when you're done.
To reduce damage to better-quality boards, use finish nails, and pull them
through the back side when you're done.
Some newer saws have blade guards
that are designed to retract even when
you're sawing at an angle. But even with
these newer designs, it's easier to get an
angled cut started if you first retract the
blade guard. Once you're a few inches
into the cut, slowly release the blade
guard so it rests on the board. If you try
to start an angled cut without retracting
the blade guard, the guard can catch on
the wood and cause the saw blade to
bind or the cut to wander off course.
Cutting along a straight line is a skill
that takes practice. Once the saw blade
is aligned and cutting along the line, it
doesn't take much effort to keep the
blade on track. But if you get off to a
crooked start, it's difficult to guide the
saw back to the line. Don't try to steer
the blade back onto the line. Instead,
stop and let the blade stop spinning.
Then withdraw the saw from the cut,
sight along the line and start again.
With practice, you'll be cutting straight
When you're cutting joists or other heavy pieces of
lumber, it's often easier to cut them where they lie
rather than hoist them onto sawhorses. An easy way
to do this is to simply rest the board on your toe and
lean it against your shin. Then align the saw with
your mark and let gravity help pull the saw through
the cut. Do be careful to keep the saw cut at least
12 in. from your toe.
Making long narrow rip cuts with a circular saw is
easy if you use your index finger as a guide. Align the
blade with the line. Then pinch the saw base between
your thumb and index finger and let your finger ride
along the edge of the board to guide the cut. This technique
is safe as long as you grip the saw before turning
it on and don't release it until the blade stops.
Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.
Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.
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