Shears, lawn mowers, clippers and loppers all have blades that can dull over time, rendering them ineffective. To fix this problem, you need to know how to sharpen garden tools to keep them at their best. Before you sharpen a blade, make sure it needs sharpening. Assuming it does, here are a few methods of restoring the cutting edge.
Check the pivot nuts that hold the blade or blades to the garden tool. These nuts can loosen and cause the blade to function improperly. Tighten the pivot nut if it is loose. If the pivot nut is tight and the blade still seems dull, proceed to the next step.
Check to see if a blade is bent. Lay a section of wood as long as the blade alongside the blade. If the blade veers away from the wood, it is bent. Place the blade in a vice so the bend is to one side of the vice. Tap the blade in the direction you want the blade to bend. If the blade is not bent, move to the next step to sharpen it.
Use the mill file to sharpen small blades and shears. Use the scissor sharpeners for grass clippers; these will work just as the mill file does.
Use long, broad strokes to file the blades of garden tools. Sharpen the blade by using strokes that move away from you. Adjust the angle to file the edge of the blade evenly. Examine the exposed edge when shiny steel starts to show. For larger blades, proceed to the next step.
Place the larger blade on plywood. File the blade with 300-grit wet/dry sandpaper. Keep the blade flat and sand using a circular motion. Move in a pattern away from you as you did in the previous step.
Check for burrs and smooth these out when you find one. Sharpen only to the factory-cut bevel of the blade so you don't cause the blade to become brittle. Oil the blade lightly with the 3-in-1 oil so it operates smoothly and is protected from rust.