Cut an 8-inch long section of 2-inch-wide angle iron with a hacksaw.
Position the angle iron on a bench grinder's tool rest so that the L faces upward on the right side and the long edge of the iron is perpendicular to the grinding face of the wheel. The leading edge of the angle iron should be about a half-inch away from the wheel.
Clamp the angle iron into place using a C-clamp.
Place a chisel or gouge in the inside V of the angle iron, so the beveled edge faces downward. Loosen the wing nut on the tool rest and adjust the angle of the jig so that the beveled edge of the tool is perfectly flat against the grinding wheel. Tighten the wing nut to lock the tool rest and jig into position.
Turn on the grinder. Ease the tool forward on the homemade tool sharpening jig to engage the tool with the grinding wheel. Grind in short 2 to 3-second bursts, lifting the tool off after each grinding to visually inspect the grinding. If the wheel isn't grinding the entire face of the bevel equally, adjust the angle of the tool rest and try again.