Keeping your woodworking tools sharp is a necessary step, as it is difficult to enjoy working with wood when you're using dull tools. In fact, using dull hand planes can waste time and materials, not to mention being frustrating to work with. Though it's a time consuming activity, sharpening hand plane blades must be done no matter how often you use the tools in your workshop. Regardless of the method you choose for sharpening your tools, always remember that it will be a lot easier to sharpen your tools when you keep them sharp, rather than waiting years between sharpening your favorite planes.
In part, the necessary sharpness depends on the type of plane and its use. For example, a general woodworking blade may only require 400 grit, while cabinetmakers' blades and other hand planes designed for very fine work need to be honed with at least 600 grit so that they are as smooth and sharp as possible.
Although it is possible to send your planes out for sharpening, if you're like most hobbyists, you can't afford to do this. Luckily, it is relatively easy to learn how to sharpen them yourself. Like most projects involving woodworking, it's important to have the right tools before you start. To sharpen hand tools such as planes, you can use nearly any knife sharpening method, such as a wet stone or dry stone, or an electric sharpener or grinder. Some plan designs will require a crock stick or a sharpening rod.
To sharpen the blade of a hand plane, the first step is to remove the blade from the plane. The next step is to examine the blade. Is it perfectly straight, or curved? If the blade is meant to be slightly curved, you'll need to make sure to maintain this shape during the sharpening process. Are there any large nicks or breaks that may not be removable using typical sharpeners?
Most hand planes have a specific angle, which may be disclosed by the manufacturer. For example, many Stanley smoothing planes have a 25 degree angle. As much as possible, you'll want to avoid changing the angle of the blade by using an angle guide. Now, sharpen the blade as you would a knife. Depending on its design, you may need a very thin sharpening rod to fit between the blade and the surrounding metal edges. This steel rod will gently remove layers of metal until the blade is sharpened.
Other planes can be sharpened with nearly any knife sharpening system, since the cutting edge is exposed. Place the blade on your work surface, beveled-side up, or hold the blade against a sharpening wheel with this side facing the wheel. Always make sure that the cutting edge stays level with the sharpener, or you will end up taking too much metal off one side of the blade, making it uneven.
Once you think that you are done sharpening, test the plane out on a piece of scrap wood. If it creates visible lines or does not glide across the wood easily, it needs more sharpening. You can also visibly inspect the blade for burrs or nicks, which mean that the blade has not been sharpened to perfection.
