Dark Matter Composites (Redbourn, Hertfordshire, U.K.) has introduced an off-the-shelf Step Sanding Tool Kit for carbon fiber composite repairs. It reportedly enables preparation of step-sanded repair surfaces in less time than scarf surfaces, typically with time savings of 50 to 75 percent, says Dark Matter. The tool kit consists of a modified Dynabrade air router (Dynabrade Inc., Clarence, N.Y.) combined with diamond surface planing heads and flexible jigs that reportedly can produce step-sanded repair surfaces on parts with double curvature. The kit is designed to accommodate repair areas up to 1,220 mm/48 inches in diameter, in step increments as small as 1 mm/0.0625 inch and depth increments of 0.05 mm/0.002 inch. All jigs are laser engraved with metric and imperial scales for both radii and diameters. The jigs also can be used to prepare repair materials. A range of diamond planing heads enable removal of a variety of composite materials, from course to fine, including gel coats, hand-laid chopped strand mats, woven prepreg fabrics and unidirectional, stitched fabrics and veils.