Abstract: A porous panel cutting and forming device and method is provided including a support and guide block with an "L" shaped guide slot into which a pivot guide pin is inserted depending downwardly from a radial arm with a knife blade depending from an end. The arm member is pushed or pulled along the slot to cut the straight edge and then rotated ninety degrees while the guide pin remains relatively stationary in the guide slot, followed by movement of the arm member along the straight section of the slot to finish the cut forming a top or bottom panel section of a ninety degree angle curved heating and air conditioning duct section. The back of the duct section to be attached to the curved portion of the corner is formed in a curved shape after cutting parallel slits one inch apart transverse across the panel at a forty-five degree angle to the surface.