3M Wetordry paper sheet enable the user to rinse areas of the workpiece and the sheet during use to prevent dust and debris from clogging the points of the abrasive and reduce air-borne dust, while producing a faster cut at the same time. These versatile sheets are ideal on surfaces that tend to generate a lot of dust, such as paint and primer, and can also be used dry for finishing metal and gel coats. In the marine industry they are used for sanding old finishes, fine feather edging and surface work. - 3M Wetordry paper sheet 431Q features extra-fast cutting silicon carbide on a strong C-weight, waterproof paper backing to provide superior finishing for both wet and dry applications on a variety of substrates, including paint, primer, gel coat, metal and wood. Silicon carbide is a very hard mineral characterized by sharp points that fracture easily, resulting in freshly exposed sharp edges that cut extra fast and produce a smooth, professional-looking finish.