SafetyWatch: Safely sharpen blades

There are a few things to keep in mind when sharpening blades.

Make sure the grinder’s guards are properly in place and the tool rest is about one-eighth of an inch from the stone and sitting at a 90-degree angle from the stones as they turn.

The blade needs to fit, but if the gap is too wide, the turning stone might suck in the blade—and possibly your fingers. The blade also could fly off the machine or get jammed.

As the grinding stones wear down, the distance between the stones and the tool rest will get wider and have to be adjusted. Check the distance every time you use the bench grinder. Unplug the grinder before making adjustments.

Next, check the blade you’re going to sharpen for deep nicks or cracks. The sharpening process will take most of the small nicks out of the blade, but larger nicks may need to be repaired.

Once you’re satisfied with the blade and wearing personal protective equipment, you can turn on the bench grinder. Hold the blade firmly along the backside of the blade.

Set the blade on the tool rest and slide it along the grinding stone at about a 45-degree angle using a slow, deliberate movement. Notice the sparks. After three or four passes, the blade will be sharp again. Turn the blade around and do the opposite end.

The sharpened edges may be very hot when you’re done sharpening, so you may want to cool the blades with water when you’re finished.

Video: Greenius