Things You'll Need
Sharpening a chain saw is a necessary task for those who use the tool frequently. Dull blades cause the chain to catch and drag or make uneven cuts. If the blades are not sharpened properly, these problems can still occur due to uneven blade edges. A Clamp-On File-N-Guide is a device that helps to make even and regular edges on your chain saw blades. A properly working chain saw needs evenly filed and sharp edges on all the blades, and the file guide allows you to precisely set the depth and angle to help in the sharpening process.
Tighten the chain on the saw so there is no slack in it. This is not ideal when using the chain saw but it keeps the chain links rigid while you are sharpening the blades.
Slide the clamping portion of the Clamp-On File-N-Guide tool down onto the chain saw bar. Move it to the center of the bar and position the support arm on the clamp portion beneath the cutter edge of the link closest to the center. This arm supports the link while you file. Now tighten the wing nut on the clamp to secure it in place.
Loosen the adjustment knob for the file and swing the file into the cutter. The cutter is the curved portion of the blade that is slightly higher than the rest. This part catches and cuts the material when the saw is in use.
Adjust the angle of the guide so the file rests smoothly against the cutter blade and then tighten it down.
Check the height adjustment of the file against the cutter blade. A too shallow angle to the cut will dull the blade quickly, and too blunt an angle will cause the blade to drag. Practice matching the angle of a newer blade -- one that is being sharpened for the first time works best -- so you can see the correct angles for sharpening.
Wear the safety glasses as you work. Apply lubricating oil to the file to keep it wet during use. File with long smooth strokes the length of the file, in one direction.
Count the number of strokes it takes to sharpen the cutter to a fine edge. Use the exact same number of strokes on each cutter on the blade so they are uniform. File each cutter on that side of the chain by rotating the chain forward after you finish each cutter.
Loosen the clamp and remove it. Turn it to the opposite side of the bar and re-clamp the guide. Adjust your angles to match the ones you used on the first side of the chain, so that the cutters on this side that go in the opposite direction will be the same.
File the cutters on the opposite side of the chain using the same number of strokes per cutter as you did on the first side.
Release the file guide from the chain saw. Return the chain to the proper tension for use when cutting. Wipe any excess oil off the chain saw and file with a clean rag.