3M's 3/4 oz. Bondo® Cream Hardener supports the fill stage of body repair by helping two-part fillers cure into durable, sandable repairs. Once properly mixed, the resulting filler can be used for repairing and shaping compatible surfaces including metal, masonry, concrete, painted wood, bare wood, and drywall. 3M notes that the resulting repair can be sanded in about 15 minutes and painted in about 45 minutes, depending on conditions and the filler used. For DIY bodywork and professional repair, proper mixing technique is important for achieving a smooth, dependable repair and minimizing pinholes.