My Father Sharpening A Folding Knife

This is a short video clip of my father sharpening a folding knife using an oil-stone. He is pressing the edge of the blade on the oil-stone, moving it forwards and back along the entire edge of the blade keeping the edge pressing down on the stone at the same angle. He likes testing the sharpness of the blades he sharpen by shaving a patch of hair from his hairy arms! :)