Is Your Miter Saw Square?

Is your miter saw square?

Q. I want to adjust my miter saw so it’s dead-on accurate,
but I don’t have a fancy square. How do I do it?

A. Use an old woodworker’s trick: set up your saw as close
as you can with whatever square you have (see photo below),
saw a board in half (Photo 1) and flip over one side (Photo 2).
When your saw is dead on, the two cut ends will
butt perfectly together. If there’s a gap in the
front of the joint (Photo 3), it means the
saw blade is angled a bit to the left.
If there’s a gap in the back, the
saw blade is angled to the right.
The gap itself is actually
twice the amount that your
saw is off, because you’re
comparing two cut ends to
each other.

Most miter saws can be
adjusted by loosening some screws
and pivoting the fence. Refer to your
owner’s manual for details.

Click any image to view a larger version.

1. Cut a trial
board in half.
It must have
absolutely
straight and
parallel sides.
Secure it with
hold-downs or
clamps.

2. Flip over the
right half, hold
it tight against
the miter saw’s
fence and butt it
up to the left
half.

3. A gap between
the two cut
ends indicates
the saw isn’t set
square.The gap
represents twice
the error.

Don't do this!

Q. When I bought my first cordless
drill, I was told to drain the battery all the
way down before recharging to prolong
the life of the battery. I used to clamp the
switch until the drill quit running. Now I
hear this is a bad practice.What gives?

A. Don’t drain your battery! Actually,
you can stick your battery in the charger
anytime you like.Draining the battery all
the way down is a bad idea, for any drill,
whether it has a NiCd or NiMH battery.
The practice will cause heat to build up in
the battery. This can actually shorten its
life, just the opposite of what you intend.A
good rule of thumb is to recharge the battery
at the first sign of power loss. Let the
battery rest and cool for 10 minutes or so
before plunking it in the charger.

Attack of the powder post beetle

Q. I just noticed that my stack of airdried
oak is peppered with tiny holes. I
also noticed little piles of fine dust on and
around the stack.What can I do to save
my wood?

A. You’re probably looking at a powder
post beetle infestation. These pests particularly
love the sapwood in hardwoods
like red oak and ash.The problem usually
manifests itself when the beetles begin to
exit the lumber in the springtime. They
push the dust (called frass) that is packed
into the holes out ahead of themselves.

You can help prevent future infestations
by maintaining a tidy area around wood
that’s air drying outdoors.Remove scraps,
sawdust, vegetation, etc.

Once an infestation is discovered you
have two choices.You can take the wood to
a kiln to finish the drying process. Kilns
will heat the wood to 140 degrees F or
more and that will kill the beetles. Your
other recourse is to have the pile fumigated
by a pest control company.You may have
to call around to find a company familiar
with the problem.

This story originally appeared in American Woodworker January 2004, issue #105.

January 2004, issue #105

Purchase this back issue.