Planing narrow planes

To guide the plane securely on the narrow side surface of the board, use a thrust washer made of a piece of board, clamp screwed to its side. It will ensure the perpendicularity of the planed surface to the side. The guide washer should protrude at least 5 cm below the foot of the plow. The greater the extension, the more precise the perpendicularity of the planed surface.