The Leatherman Wave multitool has two blades, one straight and one serrated. They are razor-sharp when they come from the factory and will keep their edge well. But eventually you will want to sharpen the blades as they dull with use. The straight blade can be sharpened with a whetstone, but the serrated blade needs to be sharpened with a cone-shaped sharpener, taking care not to damage the flat side of the blade that supports the serrations.
Place the whetstone on a nonslip surface with the coarse grit side up. This side of the stone is used to take the old blade down to a point where you can make a new edge. Unless you do this preparatory work, you will not be able to get a keen edge on the blade. Make sure the stone is at a height where you can easily work with it while keeping the blade at a fixed angle.
Hold the Leatherman with the blade at an angle of about 20 degrees. This is a good angle to start, but you might find that it needs to be a little more or less--you should be able to feel when the blade has good contact with the stone. You can work the stone without lubrication, but if you want to use anything on it, use water. Although you can use oil, it tends to clog the stone.
Slide the blade slowly over the stone, applying light pressure. Try to maintain the same angle all the time and keep the length of the blade in contact with the whetstone. Don't slide the blade back and forth, but keep it moving in the same direction, from the heel of the blade to the tip, pulling it slightly toward you at the same time. As you work on this, a burr will be created against the bevel on the other side of the blade. This is a sign that this stage is complete. It should take only seven to 10 strokes to achieve this.
Turn the knife blade over and do the same for the other side, again using seven to 10 strokes to raise a burr.
Turn the whetstone to the fine side and repeat the operation for both sides of the blade. Be careful to maintain the correct angle and keep the blade moving in the same direction. Sliding it off the edge of the stone will help raise the burr.
Remove the burr and finish the edge with a fine, or smooth, sharpening steel. Use the same angle that you used on the whetstone, and again, use only a few strokes. Do not apply too much pressure; the action of stroking across the steel will do the job.
Wipe the edge with a cloth to remove any minute filings of steel that remain, then check the blade for sharpness.
Sharpen the serrated edge with a cone-shaped sharpener, using the same principles of maintaining a constant angle of about 20 degrees and stroking in one direction only--away from the blade--for seven to 10 strokes. Finish by running the steel over in the same direction, then wipe clean.