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 worse.
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!