How to Sharpen a Pruner or a Lopper
- 1). Wipe the surface of the blades with oil or solvent, depending what type of dirt and sticky material is on the equipment. Use a rag or a steel scrubber for extremely dirty blades. The scrubber and some oil will remove most rust off of metal. Wipe the surfaces with a clean rag after the residue is removed and then oil the moving parts on the pruning tools.
- 2). Soak a wetstone in a container with enough water to cover it. Soak it for at least an hour. An alternative is to coat it with oil, but this is messier. You may also use a diamond file to sharpen the blades. It will last a lifetime and does not need a lubricant, but the file is moved over the blades rather than the blade moving over the honing instrument, as with a wetstone. Either one will work, but one may feel more natural to you.
- 3). Use the grittier side of the wetstone or diamond file first. It will remove nicks and burrs and begin to hone blades that have been neglected. Blades that are regularly sharpened will be quicker and have a keener edge than neglected pruning tools.
- 4). Hold the blade at a 20-degree angle to the wetstone or hold the file at an angle to the blade. Swipe the blade across the honing instrument 10 to 15 times or until you can look down the blade and see that there are no obvious imperfections. You will need to do this in good light. Some blades have two sides to them, so don't forget to turn the tool around so you can work on the other side of the blade.
- 5). Change to the finer side of the honing instrument and repeat the process. This time you will need more passes to create a keen edge. Most cutting blades are curved, so you will need to adjust your hold to swipe each part of the metal over the sharpener. For every 10 passes to the outer bevel, apply one pass to the thinner, inner bevel.
- 6). Hold the blade up to a bright light. If you can see light reflecting off the honed edge, there are still imperfections to remove. Continue sharpening until no light reflects. Finish by wiping the blades with oil and then buffing them with a rag.
Source...