Chisels require a sharp edge with a bevel set at a specific angle. The bevel moves wood shavings away from the cut area and determines the pressure required to cut into wood. Sharpening the angle of a chisel incorrectly causes the chisel to tear rather than cut through wood. Determining the bevel angle prior to sharpening the chisel ensures that the chisel cuts cleanly without damaging delicate woods.
Set the guide of a bench grinder 90 degrees to the face of a medium-grit grinding wheel. Turn on the bench grinder. Hold the chisel -- bevel side up -- on the guide. Push the cutting end of the chisel toward the spinning grinding wheel.
Place a sharpening stone -- coarse side up -- on a firm work surface. Coat the surface of the stone with oil.
Set the cutting tip of the chisel on the end of the oiled stone. Hold the chisel perpendicular to the surface of the stone. Move the chisel back and forth across the stone to sharpen the tip.
Hold the back of the chisel against the lower edge of an angle finder. Pull the angle finder arm tight to the bevel on the chisel blade. Read the angle shown on the angle finder head.
Adjust the bench grinder guide to the angle of the bevel.
Push the chisel blade toward the grinding wheel with the front face of the chisel tight to the guide. Remove the chisel. Check the bevel for grind marks running from the tip to the end of the bevel. Adjust the guide to ensure that the entire surface of the bevel contacts the grinding wheel.
Push the bottom of the chisel across the oiled sharpening stone. Inspect the back edge of the chisel. Stop polishing when no marks remain on the metal. Hold the end of the chisel at a 15-degree angle to the surface of the sharpening stone. Push the chisel across the stone until the edge is free of burrs.
Flip over the sharpening stone. Add oil to the sharpening stone. Work the chisel point across the stone to refine the cutting edge.
Pull the backside of the chisel across a piece of rawhide leather to remove microscopic defects in the cutting edge. Test the chisel on a piece of wood. Continue to hone the chisel until it cuts cleanly through the wood.