A grinder is a tool used for cutting, grinding and polishing surfaces, materials and other tools. There are several kinds of grinders, such as hand held or angle grinders and industrial machine grinders. For axe sharpening specifically, the common and popular choice is the angle grinder. Typically, a grinder tool uses an abrasive wheel or a disc that rotates with the help of an electric motor, petrol engine or even compressed air. If you want to keep tools such as axes and knifes extremely sharp, learn how to use a grinder for that task.
Check your axe prior to sharpening. Note that the metal head of the axe needs to be firmly and securely attached to its wooden handle. Otherwise, the head could slip or fall off and seriously hurt you during the sharpening process. If the axe head is really loose and even damaged, your axe may be too old and therefore unsafe to use. Also, if the blade of your axe is chipped or dented, it is necessary to buy a new axe.
Clean the blade of your axe, especially if you notice signs of rusting. Use a steel wool pad to remove any rust and dirt, then treat the surface with fine grit sandpaper as well.
Place the blade of your axe in a table vice to secure it during the sharpening process. Make sure to close the two jaws of the vice so the axe head is firm and stable in its position. Before turning on the grinder and starting the actual sharpening, put on safety goggles and mask as well as ear pads and protective working gloves.
Turn on your angle grinder tool. Hold it firmly with both hands. If the angle grinder is attached to a power outlet, make sure the cord is long enough so you can work your way around the axe in the vice. Also, stand solidly and hold your legs slightly apart for the most stable position.
Grind the surface of the axe blade with the rotating disc of the angle grinder. Hold the grinder to the axe at an angle between 5 and 15 degrees. Also, be careful never to chip the edge of the blade. Note that the original bevel of the blade has to be preserved. The bevel is the curve and length of the blade; don't shorten the blade or dull it by grinding at an angle of more than 15 degrees. Sharpen the axe blade with slow, long and continuous straight strokes over its metal surface, making sure not to overheat the edge of the blade in the process.
Continue the same process for the other side of the axe blade. Note that the rotating disc needs to treat the whole surface of the blade's edge evenly in order to get the best result. After you have sharpened the axe, allow the blade to cool off for at least 10 minutes. Do not forget to turn off the grinder tool after the sharpening is finished.
Loosen the vice carefully, holding the blade with your protective gloves so the axe doesn't fall. Be careful--the blade may still be hot, and it's certainly sharp enough to hurt your hands. Remove the axe from the vice and store it responsibly, where it can't be reached by children or pets.
A grinder, no matter what type it is, is an extremely dangerous and potentially lethal tool or machine. Be very careful when using it. Always wear personal protective equipment when working with a grinder tool, including protective gloves and goggles, ear pads, and work clothes and boots.