Things You'll Need
Screwdriver or crescent wrench
Table clamp (optional)
A weed cutter is a fairly simple tool for scything away tough weeds from pastures and trails, and a homeowner can just as easily use this tool for yard tasks as well. Most of these tools have a serrated, saw-like cutting blade, and regular sharpening of both blades of the weed cutter is necessary to get the best results from the tool and to spare yourself a lot of needless exertion. The main difference between a double-edged and a single-edged weed cutter in this respect is merely that having two blades extends the amount of time between sharpening sessions.
Scrub and wipe away caked-on debris and grime with the wire brush and a damp rag.
Unscrew or unbolt the cutting head from the handle using a screwdriver or wrench, whichever is appropriate.
Place the cutting head in a table vise so the teeth on one side of the cutting head face up, and secure it tightly by turning the vise's lever. If you are in the field and do not have a vise, hold the cutting head between your knees so it is secure, while some of the head remains exposed and reachable.
Set the cone file into the inside of the first tooth on the cutting head. Try to match the angle of the bevel of the blade inside this tooth as closely as possible with the file. Draw the file back and forth across the blade three to six times.
Repeat for each tooth on that side of the cutting head. Flip the cutting head over and sharpen the other side in the same manner.
Apply a few drops of oil to each side of the cutting head and rub it in with another rag. Reattach the cutting head to the handle.