Make opposing 60° angled cuts in the grooved board (or whatever angle your owner's manual specifies).
A dull chainsaw can make cutting firewood a frustrating
and tiresome chore. And a do-it-yourself attempt at
sharpening the chain—especially when the job
is done by a novice—will often only make matters seem
But I've discovered, in my attempts to deal with
this never-ending problem, that a simple chainsaw sharpening guide
fashioned from a scrap piece of wood can help a
do-it-yourselfer be sure that the teeth on both
sides of the chain are filed to the same angle (which, in
turn, will often prevent the bar from curving or binding).
The makeshift guide—which took me only
minutes to cobble up—also guards against the
many scratches, cuts, and burns that can occur during a
chainsaw sharpening operation. Best of all, the filing aid
kept me from spending good money for a commercially
available, mass-produced sharpening brace.
Here's What You Do
Find a straight-grained section of 2 X 2 hardwood that's
about 14" long. Mark the center line on one side of the
board ... then nail the piece to another plank or—if
you prefer—clamp it in a vise.
Next, using your chain saw, carefully cut a groove 3/4"
deep and 10"-long at the centerline. Then,
measuring an overall length of 8", mark and cut the ends at opposing 60° angles (or to the angle
specified In your chainsaw owner's manual).
Now, to Sharpen ...
Use the form by setting the groove over the chain ahead of
each tooth along the right side. (Be sure to allow 1/8"
clearance between the board and the file.) Then, as you
make your stroke, visually align your file with
the guide's end.
And how do you sharpen the left-hand teeth? Why, simply by
placing the opposite end of the block on top of the chain, 1/8" behind the teeth's leading or cutting edges!