To repair cracks in a Corian sink, clean the crack with soapy solution and hydrogen peroxide; sand the crack; heat the interior of the crack and surrounding areas; fill the crack with epoxy seam sealer; and sand over crack. Clean the area thoroughly before using the sink. You need a hair dryer, a craft stick, sandpaper, orbital sander and paper towels for the repair.
Mix dish detergent with warm water in a cup, dip a stiif-bristled brush into the soultion, and use it to clean the crack. Dry the area with a paper towel. Dampen a cotton swab with hydrogen peroxide, and use it to clean the inside of the crack to remove bacteria and dirt buildup. Allow the crack to dry completely.
Use an orbital sander with a 220-grit sandpaper to sand the inside and edges of the crack to smoothen the area and flatten any protrusions. Moisten a paper towel, and remove dust. Dry the crack. Apply heat to the crack and surrounding areas with a hair dryer for about 15 minutes.
Mix epoxy seam sealer in a paper plate with a craft stick, and apply a bead of the sealer along the crack. Wipe away excess sealer and, according to the manufacturer's recommendations, allow the epoxy to dry. Lightly sand over the crack with 320-and 400-grit sandpapers. Remove any dust with a dampened paper towel. Clean the sink with soapy water.